Webview 兼容android4.4版本上传本地图片

针对Webview 支持上传本地图片情况，查询大量资料后发现对版本4.4兼容没有现成的解决方案，目前根据现有开源源码做个修改，可以支持兼容支持4.4版本上传图片：

具体是在onActivityResult 里多加了层判断：

 /*
          * 若当前版本API为19, 则把Uri路径转换成new File性质的Uri路径
          * 若非 则按照之前方法调用即可
          * */
          if (Build.VERSION.SDK_INT == 19) {
          
              String realPathFromURI = getRealPathFromURI(intent.getData());
              File file = new File(realPathFromURI);
              if(file.exists()){
                  Uri uri = Uri.fromFile(file);
                  mFileUploadCallbackFirst.onReceiveValue(uri);
               }
 
            } else {
                 mFileUploadCallbackFirst.onReceiveValue(intent.getData());
            }

根据Uri 获取图片真实路径的方法用的是：

  /*
    * 
    * 获取Uri图片真实路径的方法
    * */
    public String getRealPathFromURI(Uri contentUri) {
        String res = null;
        String[] proj = {MediaStore.Images.Media.DATA};
        Cursor cursor = mContext.getContentResolver().query(contentUri, proj, null, null, null);
        if (cursor.moveToFirst()) {
            int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            res = cursor.getString(column_index);
        }
        cursor.close();
        return res;
    }

此方法，测试后webview可以兼容4.4版本上传本地图片。

修改源码后的所有代码 如下：

import android.annotation.SuppressLint;
import android.app.Activity;
import android.app.DownloadManager;
import android.app.Fragment;
import android.content.Context;
import android.content.Intent;
import android.content.pm.ApplicationInfo;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.net.Uri;
import android.net.http.SslError;
import android.os.Build;
import android.os.Environment;
import android.os.Message;
import android.provider.MediaStore;
import android.util.AttributeSet;
import android.util.Base64;
import android.view.InputEvent;
import android.view.KeyEvent;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.ClientCertRequest;
import android.webkit.ConsoleMessage;
import android.webkit.CookieManager;
import android.webkit.DownloadListener;
import android.webkit.GeolocationPermissions;
import android.webkit.HttpAuthHandler;
import android.webkit.JsPromptResult;
import android.webkit.JsResult;
import android.webkit.PermissionRequest;
import android.webkit.SslErrorHandler;
import android.webkit.URLUtil;
import android.webkit.ValueCallback;
import android.webkit.WebChromeClient;
import android.webkit.WebResourceRequest;
import android.webkit.WebResourceResponse;
import android.webkit.WebSettings;
import android.webkit.WebStorage;
import android.webkit.WebView;
import android.webkit.WebViewClient;
 
 
import java.io.File;
import java.io.UnsupportedEncodingException;
import java.lang.ref.WeakReference;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.MissingResourceException;
 
/*
 * Android-AdvancedWebView (https://github.com/delight-im/Android-AdvancedWebView)
 * Copyright (c) delight.im (https://www.delight.im/)
 * Licensed under the MIT License (https://opensource.org/licenses/MIT)
 */
 
/**
 * Advanced WebView component for Android that works as intended out of the box
 */
@SuppressWarnings("deprecation")
public class MyWebView extends WebView {
 
    private Context mContext;
 
    public interface Listener {
        void onPageStarted(String url, Bitmap favicon);
 
        void onPageFinished(String url);
 
        void onPageError(int errorCode, String description, String failingUrl);
 
        void onDownloadRequested(String url, String suggestedFilename, String mimeType, long contentLength, String contentDisposition, String userAgent);
 
        void onExternalPageRequest(String url);
    }
 
    public static final String PACKAGE_NAME_DOWNLOAD_MANAGER = "com.android.providers.downloads";
    protected static final int REQUEST_CODE_FILE_PICKER = 51426;
    protected static final String DATABASES_SUB_FOLDER = "/databases";
    protected static final String LANGUAGE_DEFAULT_ISO3 = "eng";
    protected static final String CHARSET_DEFAULT = "UTF-8";
    /**
     * Alternative browsers that have their own rendering engine and *may* be installed on this device
     */
    protected static final String[] ALTERNATIVE_BROWSERS = new String[]{"org.mozilla.firefox", "com.android.chrome", "com.opera.browser", "org.mozilla.firefox_beta", "com.chrome.beta", "com.opera.browser.beta"};
    protected WeakReference<Activity> mActivity;
    protected WeakReference<Fragment> mFragment;
    protected Listener mListener;
    protected final List<String> mPermittedHostnames = new LinkedList<String>();
    /**
     * File upload callback for platform versions prior to Android 5.0
     */
    protected ValueCallback<Uri> mFileUploadCallbackFirst;
    /**
     * File upload callback for Android 5.0+
     */
    protected ValueCallback<Uri[]> mFileUploadCallbackSecond;
    protected long mLastError;
    protected String mLanguageIso3;
    protected int mRequestCodeFilePicker = REQUEST_CODE_FILE_PICKER;
    protected WebViewClient mCustomWebViewClient;
    protected WebChromeClient mCustomWebChromeClient;
    protected boolean mGeolocationEnabled;
    protected String mUploadableFileTypes = "*/*";
    protected final Map<String, String> mHttpHeaders = new HashMap<String, String>();
 
    public MyWebView(Context context) {
        super(context);
        init(context);
    }
 
    public MyWebView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context);
    }
 
    public MyWebView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context);
    }
 
    public void setListener(final Activity activity, final Listener listener) {
        setListener(activity, listener, REQUEST_CODE_FILE_PICKER);
    }
 
    public void setListener(final Activity activity, final Listener listener, final int requestCodeFilePicker) {
        if (activity != null) {
            mActivity = new WeakReference<Activity>(activity);
        } else {
            mActivity = null;
        }
 
        setListener(listener, requestCodeFilePicker);
    }
 
    public void setListener(final Fragment fragment, final Listener listener) {
        setListener(fragment, listener, REQUEST_CODE_FILE_PICKER);
    }
 
    public void setListener(final Fragment fragment, final Listener listener, final int requestCodeFilePicker) {
        if (fragment != null) {
            mFragment = new WeakReference<Fragment>(fragment);
        } else {
            mFragment = null;
        }
 
        setListener(listener, requestCodeFilePicker);
    }
 
    protected void setListener(final Listener listener, final int requestCodeFilePicker) {
        mListener = listener;
        mRequestCodeFilePicker = requestCodeFilePicker;
    }
 
    @Override
    public void setWebViewClient(final WebViewClient client) {
        mCustomWebViewClient = client;
    }
 
    @Override
    public void setWebChromeClient(final WebChromeClient client) {
        mCustomWebChromeClient = client;
    }
 
    @SuppressLint("SetJavaScriptEnabled")
    public void setGeolocationEnabled(final boolean enabled) {
        if (enabled) {
            getSettings().setJavaScriptEnabled(true);
            getSettings().setGeolocationEnabled(true);
            setGeolocationDatabasePath();
        }
 
        mGeolocationEnabled = enabled;
    }
 
    @SuppressLint("NewApi")
    protected void setGeolocationDatabasePath() {
        final Activity activity;
 
        if (mFragment != null && mFragment.get() != null && Build.VERSION.SDK_INT >= 11 && mFragment.get().getActivity() != null) {
            activity = mFragment.get().getActivity();
        } else if (mActivity != null && mActivity.get() != null) {
            activity = mActivity.get();
        } else {
            return;
        }
 
        getSettings().setGeolocationDatabasePath(activity.getFilesDir().getPath());
    }
 
    public void setUploadableFileTypes(final String mimeType) {
        mUploadableFileTypes = mimeType;
    }
 
    /**
     * Loads and displays the provided HTML source text
     *
     * @param html the HTML source text to load
     */
    public void loadHtml(final String html) {
        loadHtml(html, null);
    }
 
    /**
     * Loads and displays the provided HTML source text
     *
     * @param html    the HTML source text to load
     * @param baseUrl the URL to use as the page's base URL
     */
    public void loadHtml(final String html, final String baseUrl) {
        loadHtml(html, baseUrl, null);
    }
 
    /**
     * Loads and displays the provided HTML source text
     *
     * @param html       the HTML source text to load
     * @param baseUrl    the URL to use as the page's base URL
     * @param historyUrl the URL to use for the page's history entry
     */
    public void loadHtml(final String html, final String baseUrl, final String historyUrl) {
        loadHtml(html, baseUrl, historyUrl, "utf-8");
    }
 
    /**
     * Loads and displays the provided HTML source text
     *
     * @param html       the HTML source text to load
     * @param baseUrl    the URL to use as the page's base URL
     * @param historyUrl the URL to use for the page's history entry
     * @param encoding   the encoding or charset of the HTML source text
     */
    public void loadHtml(final String html, final String baseUrl, final String historyUrl, final String encoding) {
        loadDataWithBaseURL(baseUrl, html, "text/html", encoding, historyUrl);
    }
 
    @SuppressLint("NewApi")
    @SuppressWarnings("all")
    public void onResume() {
        if (Build.VERSION.SDK_INT >= 11) {
            super.onResume();
        }
        resumeTimers();
    }
 
    @SuppressLint("NewApi")
    @SuppressWarnings("all")
    public void onPause() {
        pauseTimers();
        if (Build.VERSION.SDK_INT >= 11) {
            super.onPause();
        }
    }
 
    public void onDestroy() {
        // try to remove this view from its parent first
        try {
            ((ViewGroup) getParent()).removeView(this);
        } catch (Exception ignored) {
        }
 
        // then try to remove all child views from this view
        try {
            removeAllViews();
        } catch (Exception ignored) {
        }
 
        // and finally destroy this view
        destroy();
    }
 
    public void onActivityResult(final int requestCode, final int resultCode, final Intent intent) {
        if (requestCode == mRequestCodeFilePicker) {
            if (resultCode == Activity.RESULT_OK) {
                if (intent != null) {
                    int sdkInt = Build.VERSION.SDK_INT;
                    android.util.Log.e("tag", "当前的版本为" + sdkInt);
                    if (mFileUploadCallbackFirst != null) {
                        /*
                        * 若当前版本API为19, 则把Uri路径转换成new File性质的Uri路径
                        * 若非 则按照之前方法调用即可
                        * */
                       <span style="color:#3333FF;"> if (Build.VERSION.SDK_INT == 19) {
 
                            String realPathFromURI = getRealPathFromURI(intent.getData());
                            File file = new File(realPathFromURI);
                           if(file.exists()){
                               Uri uri = Uri.fromFile(file);
                               mFileUploadCallbackFirst.onReceiveValue(uri);
                           }
 
                        } else {
                            mFileUploadCallbackFirst.onReceiveValue(intent.getData());
                        }</span>
 
                        mFileUploadCallbackFirst = null;
                    } else if (mFileUploadCallbackSecond != null) {
                        Uri[] dataUris = null;
 
                        try {
                            if (intent.getDataString() != null) {
                                dataUris = new Uri[]{Uri.parse(intent.getDataString())};
                            } else {
                                if (Build.VERSION.SDK_INT >= 16) {
                                    if (intent.getClipData() != null) {
                                        final int numSelectedFiles = intent.getClipData().getItemCount();
 
                                        dataUris = new Uri[numSelectedFiles];
 
                                        for (int i = 0; i < numSelectedFiles; i++) {
                                            dataUris[i] = intent.getClipData().getItemAt(i).getUri();
                                        }
                                    }
                                }
                            }
                        } catch (Exception ignored) {
                        }
 
                        mFileUploadCallbackSecond.onReceiveValue(dataUris);
                        mFileUploadCallbackSecond = null;
                    }
                }
            } else {
                if (mFileUploadCallbackFirst != null) {
                    mFileUploadCallbackFirst.onReceiveValue(null);
                    mFileUploadCallbackFirst = null;
                } else if (mFileUploadCallbackSecond != null) {
                    mFileUploadCallbackSecond.onReceiveValue(null);
                    mFileUploadCallbackSecond = null;
                }
            }
        }
    }
 
    /**
     * Adds an additional HTTP header that will be sent along with every HTTP `GET` request
     * <p/>
     * This does only affect the main requests, not the requests to included resources (e.g. images)
     * <p/>
     * If you later want to delete an HTTP header that was previously added this way, call `removeHttpHeader()`
     * <p/>
     * The `WebView` implementation may in some cases overwrite headers that you set or unset
     *
     * @param name  the name of the HTTP header to add
     * @param value the value of the HTTP header to send
     */
    public void addHttpHeader(final String name, final String value) {
        mHttpHeaders.put(name, value);
    }
 
    /**
     * Removes one of the HTTP headers that have previously been added via `addHttpHeader()`
     * <p/>
     * If you want to unset a pre-defined header, set it to an empty string with `addHttpHeader()` instead
     * <p/>
     * The `WebView` implementation may in some cases overwrite headers that you set or unset
     *
     * @param name the name of the HTTP header to remove
     */
    public void removeHttpHeader(final String name) {
        mHttpHeaders.remove(name);
    }
 
    public void addPermittedHostname(String hostname) {
        mPermittedHostnames.add(hostname);
    }
 
    public void addPermittedHostnames(Collection<? extends String> collection) {
        mPermittedHostnames.addAll(collection);
    }
 
    public List<String> getPermittedHostnames() {
        return mPermittedHostnames;
    }
 
    public void removePermittedHostname(String hostname) {
        mPermittedHostnames.remove(hostname);
    }
 
    public void clearPermittedHostnames() {
        mPermittedHostnames.clear();
    }
 
    public boolean onBackPressed() {
        if (canGoBack()) {
            goBack();
            return false;
        } else {
            return true;
        }
    }
 
    @SuppressLint("NewApi")
    protected static void setAllowAccessFromFileUrls(final WebSettings webSettings, final boolean allowed) {
        if (Build.VERSION.SDK_INT >= 16) {
            webSettings.setAllowFileAccessFromFileURLs(allowed);
            webSettings.setAllowUniversalAccessFromFileURLs(allowed);
        }
    }
 
    @SuppressWarnings("static-method")
    public void setCookiesEnabled(final boolean enabled) {
        CookieManager.getInstance().setAcceptCookie(enabled);
    }
 
    @SuppressLint("NewApi")
    public void setThirdPartyCookiesEnabled(final boolean enabled) {
        if (Build.VERSION.SDK_INT >= 21) {
            CookieManager.getInstance().setAcceptThirdPartyCookies(this, enabled);
        }
    }
 
    public void setMixedContentAllowed(final boolean allowed) {
        setMixedContentAllowed(getSettings(), allowed);
    }
 
    @SuppressWarnings("static-method")
    @SuppressLint("NewApi")
    protected void setMixedContentAllowed(final WebSettings webSettings, final boolean allowed) {
        if (Build.VERSION.SDK_INT >= 21) {
            webSettings.setMixedContentMode(allowed ? WebSettings.MIXED_CONTENT_ALWAYS_ALLOW : WebSettings.MIXED_CONTENT_NEVER_ALLOW);
        }
    }
 
    public void setDesktopMode(final boolean enabled) {
        final WebSettings webSettings = getSettings();
 
        final String newUserAgent;
        if (enabled) {
            newUserAgent = webSettings.getUserAgentString().replace("Mobile", "eliboM").replace("Android", "diordnA");
        } else {
            newUserAgent = webSettings.getUserAgentString().replace("eliboM", "Mobile").replace("diordnA", "Android");
        }
 
        webSettings.setUserAgentString(newUserAgent);
        webSettings.setUseWideViewPort(enabled);
        webSettings.setLoadWithOverviewMode(enabled);
        webSettings.setSupportZoom(enabled);
        webSettings.setBuiltInZoomControls(enabled);
    }
 
    @SuppressLint({"SetJavaScriptEnabled"})
    protected void init(Context context) {
        // in IDE's preview mode
        if (isInEditMode()) {
            // do not run the code from this method
            return;
        }
        this.mContext = context;
        if (context instanceof Activity) {
            mActivity = new WeakReference<Activity>((Activity) context);
        }
 
        mLanguageIso3 = getLanguageIso3();
 
        setFocusable(true);
        setFocusableInTouchMode(true);
 
        setSaveEnabled(true);
 
        final String filesDir = context.getFilesDir().getPath();
        final String databaseDir = filesDir.substring(0, filesDir.lastIndexOf("/")) + DATABASES_SUB_FOLDER;
 
        final WebSettings webSettings = getSettings();
        webSettings.setAllowFileAccess(false);
        setAllowAccessFromFileUrls(webSettings, false);
        webSettings.setBuiltInZoomControls(false);
        webSettings.setJavaScriptEnabled(true);
        webSettings.setDomStorageEnabled(true);
        if (Build.VERSION.SDK_INT < 18) {
            webSettings.setRenderPriority(WebSettings.RenderPriority.HIGH);
        }
        webSettings.setDatabaseEnabled(true);
        if (Build.VERSION.SDK_INT < 19) {
            webSettings.setDatabasePath(databaseDir);
        }
        setMixedContentAllowed(webSettings, true);
 
        setThirdPartyCookiesEnabled(true);
 
        super.setWebViewClient(new WebViewClient() {
 
            @Override
            public void onPageStarted(WebView view, String url, Bitmap favicon) {
                if (!hasError()) {
                    if (mListener != null) {
                        mListener.onPageStarted(url, favicon);
                    }
                }
 
                if (mCustomWebViewClient != null) {
                    mCustomWebViewClient.onPageStarted(view, url, favicon);
                }
            }
 
            @Override
            public void onPageFinished(WebView view, String url) {
                if (!hasError()) {
                    if (mListener != null) {
                        mListener.onPageFinished(url);
                    }
                }
 
                if (mCustomWebViewClient != null) {
                    mCustomWebViewClient.onPageFinished(view, url);
                }
            }
 
            @Override
            public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
                setLastError();
 
                if (mListener != null) {
                    mListener.onPageError(errorCode, description, failingUrl);
                }
 
                if (mCustomWebViewClient != null) {
                    mCustomWebViewClient.onReceivedError(view, errorCode, description, failingUrl);
                }
            }
 
            @Override
            public boolean shouldOverrideUrlLoading(final WebView view, final String url) {
                // if the hostname may not be accessed
                if (!isHostnameAllowed(url)) {
                    // if a listener is available
                    if (mListener != null) {
                        // inform the listener about the request
                        mListener.onExternalPageRequest(url);
                    }
 
                    // cancel the original request
                    return true;
                }
 
                // if there is a user-specified handler available
                if (mCustomWebViewClient != null) {
                    // if the user-specified handler asks to override the request
                    if (mCustomWebViewClient.shouldOverrideUrlLoading(view, url)) {
                        // cancel the original request
                        return true;
                    }
                }
 
                // route the request through the custom URL loading method
                view.loadUrl(url);
 
                // cancel the original request
                return true;
            }
 
            @Override
            public void onLoadResource(WebView view, String url) {
                if (mCustomWebViewClient != null) {
                    mCustomWebViewClient.onLoadResource(view, url);
                } else {
                    super.onLoadResource(view, url);
                }
            }
 
            @SuppressLint("NewApi")
            @SuppressWarnings("all")
            public WebResourceResponse shouldInterceptRequest(WebView view, String url) {
                if (Build.VERSION.SDK_INT >= 11) {
                    if (mCustomWebViewClient != null) {
                        return mCustomWebViewClient.shouldInterceptRequest(view, url);
                    } else {
                        return super.shouldInterceptRequest(view, url);
                    }
                } else {
                    return null;
                }
            }
 
            @SuppressLint("NewApi")
            @SuppressWarnings("all")
            public WebResourceResponse shouldInterceptRequest(WebView view, WebResourceRequest request) {
                if (Build.VERSION.SDK_INT >= 21) {
                    if (mCustomWebViewClient != null) {
                        return mCustomWebViewClient.shouldInterceptRequest(view, request);
                    } else {
                        return super.shouldInterceptRequest(view, request);
                    }
                } else {
                    return null;
                }
            }
 
            @Override
            public void onFormResubmission(WebView view, Message dontResend, Message resend) {
                if (mCustomWebViewClient != null) {
                    mCustomWebViewClient.onFormResubmission(view, dontResend, resend);
                } else {
                    super.onFormResubmission(view, dontResend, resend);
                }
            }
 
            @Override
            public void doUpdateVisitedHistory(WebView view, String url, boolean isReload) {
                if (mCustomWebViewClient != null) {
                    mCustomWebViewClient.doUpdateVisitedHistory(view, url, isReload);
                } else {
                    super.doUpdateVisitedHistory(view, url, isReload);
                }
            }
 
            @Override
            public void onReceivedSslError(WebView view, SslErrorHandler handler, SslError error) {
                if (mCustomWebViewClient != null) {
                    mCustomWebViewClient.onReceivedSslError(view, handler, error);
                } else {
                    super.onReceivedSslError(view, handler, error);
                }
            }
 
            @SuppressLint("NewApi")
            @SuppressWarnings("all")
            public void onReceivedClientCertRequest(WebView view, ClientCertRequest request) {
                if (Build.VERSION.SDK_INT >= 21) {
                    if (mCustomWebViewClient != null) {
                        mCustomWebViewClient.onReceivedClientCertRequest(view, request);
                    } else {
                        super.onReceivedClientCertRequest(view, request);
                    }
                }
            }
 
            @Override
            public void onReceivedHttpAuthRequest(WebView view, HttpAuthHandler handler, String host, String realm) {
                if (mCustomWebViewClient != null) {
                    mCustomWebViewClient.onReceivedHttpAuthRequest(view, handler, host, realm);
                } else {
                    super.onReceivedHttpAuthRequest(view, handler, host, realm);
                }
            }
 
            @Override
            public boolean shouldOverrideKeyEvent(WebView view, KeyEvent event) {
                if (mCustomWebViewClient != null) {
                    return mCustomWebViewClient.shouldOverrideKeyEvent(view, event);
                } else {
                    return super.shouldOverrideKeyEvent(view, event);
                }
            }
 
            @Override
            public void onUnhandledKeyEvent(WebView view, KeyEvent event) {
                if (mCustomWebViewClient != null) {
                    mCustomWebViewClient.onUnhandledKeyEvent(view, event);
                } else {
                    super.onUnhandledKeyEvent(view, event);
                }
            }
 
            @SuppressLint("NewApi")
            @SuppressWarnings("all")
            public void onUnhandledInputEvent(WebView view, InputEvent event) {
                if (Build.VERSION.SDK_INT >= 21) {
                    if (mCustomWebViewClient != null) {
                        mCustomWebViewClient.onUnhandledInputEvent(view, event);
                    } else {
                        super.onUnhandledInputEvent(view, event);
                    }
                }
            }
 
            @Override
            public void onScaleChanged(WebView view, float oldScale, float newScale) {
                if (mCustomWebViewClient != null) {
                    mCustomWebViewClient.onScaleChanged(view, oldScale, newScale);
                } else {
                    super.onScaleChanged(view, oldScale, newScale);
                }
            }
 
            @SuppressLint("NewApi")
            @SuppressWarnings("all")
            public void onReceivedLoginRequest(WebView view, String realm, String account, String args) {
                if (Build.VERSION.SDK_INT >= 12) {
                    if (mCustomWebViewClient != null) {
                        mCustomWebViewClient.onReceivedLoginRequest(view, realm, account, args);
                    } else {
                        super.onReceivedLoginRequest(view, realm, account, args);
                    }
                }
            }
 
        });
 
        super.setWebChromeClient(new WebChromeClient() {
 
            // file upload callback (Android 2.2 (API level 8) -- Android 2.3 (API level 10)) (hidden method)
            @SuppressWarnings("unused")
            public void openFileChooser(ValueCallback<Uri> uploadMsg) {
                openFileChooser(uploadMsg, null);
            }
 
            // file upload callback (Android 3.0 (API level 11) -- Android 4.0 (API level 15)) (hidden method)
            public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType) {
                openFileChooser(uploadMsg, acceptType, null);
            }
 
            // file upload callback (Android 4.1 (API level 16) -- Android 4.3 (API level 18)) (hidden method)
            @SuppressWarnings("unused")
            public void openFileChooser(ValueCallback<Uri> uploadMsg, String acceptType, String capture) {
                openFileInput(uploadMsg, null, false);
            }
 
            // file upload callback (Android 5.0 (API level 21) -- current) (public method)
            @SuppressWarnings("all")
            public boolean onShowFileChooser(WebView webView, ValueCallback<Uri[]> filePathCallback, WebChromeClient.FileChooserParams fileChooserParams) {
                if (Build.VERSION.SDK_INT >= 21) {
                    final boolean allowMultiple = fileChooserParams.getMode() == FileChooserParams.MODE_OPEN_MULTIPLE;
 
                    openFileInput(null, filePathCallback, allowMultiple);
 
                    return true;
                } else {
                    return false;
                }
            }
 
            @Override
            public void onProgressChanged(WebView view, int newProgress) {
                if (mCustomWebChromeClient != null) {
                    mCustomWebChromeClient.onProgressChanged(view, newProgress);
                } else {
                    super.onProgressChanged(view, newProgress);
                }
            }
 
            @Override
            public void onReceivedTitle(WebView view, String title) {
                if (mCustomWebChromeClient != null) {
                    mCustomWebChromeClient.onReceivedTitle(view, title);
                } else {
                    super.onReceivedTitle(view, title);
                }
            }
 
            @Override
            public void onReceivedIcon(WebView view, Bitmap icon) {
                if (mCustomWebChromeClient != null) {
                    mCustomWebChromeClient.onReceivedIcon(view, icon);
                } else {
                    super.onReceivedIcon(view, icon);
                }
            }
 
            @Override
            public void onReceivedTouchIconUrl(WebView view, String url, boolean precomposed) {
                if (mCustomWebChromeClient != null) {
                    mCustomWebChromeClient.onReceivedTouchIconUrl(view, url, precomposed);
                } else {
                    super.onReceivedTouchIconUrl(view, url, precomposed);
                }
            }
 
            @Override
            public void onShowCustomView(View view, CustomViewCallback callback) {
                if (mCustomWebChromeClient != null) {
                    mCustomWebChromeClient.onShowCustomView(view, callback);
                } else {
                    super.onShowCustomView(view, callback);
                }
            }
 
            @SuppressLint("NewApi")
            @SuppressWarnings("all")
            public void onShowCustomView(View view, int requestedOrientation, CustomViewCallback callback) {
                if (Build.VERSION.SDK_INT >= 14) {
                    if (mCustomWebChromeClient != null) {
                        mCustomWebChromeClient.onShowCustomView(view, requestedOrientation, callback);
                    } else {
                        super.onShowCustomView(view, requestedOrientation, callback);
                    }
                }
            }
 
            @Override
            public void onHideCustomView() {
                if (mCustomWebChromeClient != null) {
                    mCustomWebChromeClient.onHideCustomView();
                } else {
                    super.onHideCustomView();
                }
            }
 
            @Override
            public boolean onCreateWindow(WebView view, boolean isDialog, boolean isUserGesture, Message resultMsg) {
                if (mCustomWebChromeClient != null) {
                    return mCustomWebChromeClient.onCreateWindow(view, isDialog, isUserGesture, resultMsg);
                } else {
                    return super.onCreateWindow(view, isDialog, isUserGesture, resultMsg);
                }
            }
 
            @Override
            public void onRequestFocus(WebView view) {
                if (mCustomWebChromeClient != null) {
                    mCustomWebChromeClient.onRequestFocus(view);
                } else {
                    super.onRequestFocus(view);
                }
            }
 
            @Override
            public void onCloseWindow(WebView window) {
                if (mCustomWebChromeClient != null) {
                    mCustomWebChromeClient.onCloseWindow(window);
                } else {
                    super.onCloseWindow(window);
                }
            }
 
            @Override
            public boolean onJsAlert(WebView view, String url, String message, JsResult result) {
                if (mCustomWebChromeClient != null) {
                    return mCustomWebChromeClient.onJsAlert(view, url, message, result);
                } else {
                    return super.onJsAlert(view, url, message, result);
                }
            }
 
            @Override
            public boolean onJsConfirm(WebView view, String url, String message, JsResult result) {
                if (mCustomWebChromeClient != null) {
                    return mCustomWebChromeClient.onJsConfirm(view, url, message, result);
                } else {
                    return super.onJsConfirm(view, url, message, result);
                }
            }
 
            @Override
            public boolean onJsPrompt(WebView view, String url, String message, String defaultValue, JsPromptResult result) {
                if (mCustomWebChromeClient != null) {
                    return mCustomWebChromeClient.onJsPrompt(view, url, message, defaultValue, result);
                } else {
                    return super.onJsPrompt(view, url, message, defaultValue, result);
                }
            }
 
            @Override
            public boolean onJsBeforeUnload(WebView view, String url, String message, JsResult result) {
                if (mCustomWebChromeClient != null) {
                    return mCustomWebChromeClient.onJsBeforeUnload(view, url, message, result);
                } else {
                    return super.onJsBeforeUnload(view, url, message, result);
                }
            }
 
            @Override
            public void onGeolocationPermissionsShowPrompt(String origin, GeolocationPermissions.Callback callback) {
                if (mGeolocationEnabled) {
                    callback.invoke(origin, true, false);
                } else {
                    if (mCustomWebChromeClient != null) {
                        mCustomWebChromeClient.onGeolocationPermissionsShowPrompt(origin, callback);
                    } else {
                        super.onGeolocationPermissionsShowPrompt(origin, callback);
                    }
                }
            }
 
            @Override
            public void onGeolocationPermissionsHidePrompt() {
                if (mCustomWebChromeClient != null) {
                    mCustomWebChromeClient.onGeolocationPermissionsHidePrompt();
                } else {
                    super.onGeolocationPermissionsHidePrompt();
                }
            }
 
            @SuppressLint("NewApi")
            @SuppressWarnings("all")
            public void onPermissionRequest(PermissionRequest request) {
                if (Build.VERSION.SDK_INT >= 21) {
                    if (mCustomWebChromeClient != null) {
                        mCustomWebChromeClient.onPermissionRequest(request);
                    } else {
                        super.onPermissionRequest(request);
                    }
                }
            }
 
            @SuppressLint("NewApi")
            @SuppressWarnings("all")
            public void onPermissionRequestCanceled(PermissionRequest request) {
                if (Build.VERSION.SDK_INT >= 21) {
                    if (mCustomWebChromeClient != null) {
                        mCustomWebChromeClient.onPermissionRequestCanceled(request);
                    } else {
                        super.onPermissionRequestCanceled(request);
                    }
                }
            }
 
            @Override
            public boolean onJsTimeout() {
                if (mCustomWebChromeClient != null) {
                    return mCustomWebChromeClient.onJsTimeout();
                } else {
                    return super.onJsTimeout();
                }
            }
 
            @Override
            public void onConsoleMessage(String message, int lineNumber, String sourceID) {
                if (mCustomWebChromeClient != null) {
                    mCustomWebChromeClient.onConsoleMessage(message, lineNumber, sourceID);
                } else {
                    super.onConsoleMessage(message, lineNumber, sourceID);
                }
            }
 
            @Override
            public boolean onConsoleMessage(ConsoleMessage consoleMessage) {
                if (mCustomWebChromeClient != null) {
                    return mCustomWebChromeClient.onConsoleMessage(consoleMessage);
                } else {
                    return super.onConsoleMessage(consoleMessage);
                }
            }
 
            @Override
            public Bitmap getDefaultVideoPoster() {
                if (mCustomWebChromeClient != null) {
                    return mCustomWebChromeClient.getDefaultVideoPoster();
                } else {
                    return super.getDefaultVideoPoster();
                }
            }
 
            @Override
            public View getVideoLoadingProgressView() {
                if (mCustomWebChromeClient != null) {
                    return mCustomWebChromeClient.getVideoLoadingProgressView();
                } else {
                    return super.getVideoLoadingProgressView();
                }
            }
 
            @Override
            public void getVisitedHistory(ValueCallback<String[]> callback) {
                if (mCustomWebChromeClient != null) {
                    mCustomWebChromeClient.getVisitedHistory(callback);
                } else {
                    super.getVisitedHistory(callback);
                }
            }
 
            @Override
            public void onExceededDatabaseQuota(String url, String databaseIdentifier, long quota, long estimatedDatabaseSize, long totalQuota, WebStorage.QuotaUpdater quotaUpdater) {
                if (mCustomWebChromeClient != null) {
                    mCustomWebChromeClient.onExceededDatabaseQuota(url, databaseIdentifier, quota, estimatedDatabaseSize, totalQuota, quotaUpdater);
                } else {
                    super.onExceededDatabaseQuota(url, databaseIdentifier, quota, estimatedDatabaseSize, totalQuota, quotaUpdater);
                }
            }
 
            @Override
            public void onReachedMaxAppCacheSize(long requiredStorage, long quota, WebStorage.QuotaUpdater quotaUpdater) {
                if (mCustomWebChromeClient != null) {
                    mCustomWebChromeClient.onReachedMaxAppCacheSize(requiredStorage, quota, quotaUpdater);
                } else {
                    super.onReachedMaxAppCacheSize(requiredStorage, quota, quotaUpdater);
                }
            }
 
        });
 
        setDownloadListener(new DownloadListener() {
 
            @Override
            public void onDownloadStart(final String url, final String userAgent, final String contentDisposition, final String mimeType, final long contentLength) {
                final String suggestedFilename = URLUtil.guessFileName(url, contentDisposition, mimeType);
 
                if (mListener != null) {
                    mListener.onDownloadRequested(url, suggestedFilename, mimeType, contentLength, contentDisposition, userAgent);
                }
            }
 
        });
    }
 
    @Override
    public void loadUrl(final String url, Map<String, String> additionalHttpHeaders) {
        if (additionalHttpHeaders == null) {
            additionalHttpHeaders = mHttpHeaders;
        } else if (mHttpHeaders.size() > 0) {
            additionalHttpHeaders.putAll(mHttpHeaders);
        }
 
        super.loadUrl(url, additionalHttpHeaders);
    }
 
    @Override
    public void loadUrl(final String url) {
        if (mHttpHeaders.size() > 0) {
            super.loadUrl(url, mHttpHeaders);
        } else {
            super.loadUrl(url);
        }
    }
 
    public void loadUrl(String url, final boolean preventCaching) {
        if (preventCaching) {
            url = makeUrlUnique(url);
        }
 
        loadUrl(url);
    }
 
    public void loadUrl(String url, final boolean preventCaching, final Map<String, String> additionalHttpHeaders) {
        if (preventCaching) {
            url = makeUrlUnique(url);
        }
 
        loadUrl(url, additionalHttpHeaders);
    }
 
    protected static String makeUrlUnique(final String url) {
        StringBuilder unique = new StringBuilder();
        unique.append(url);
 
        if (url.contains("?")) {
            unique.append('&');
        } else {
            if (url.lastIndexOf('/') <= 7) {
                unique.append('/');
            }
            unique.append('?');
        }
 
        unique.append(System.currentTimeMillis());
        unique.append('=');
        unique.append(1);
 
        return unique.toString();
    }
 
    protected boolean isHostnameAllowed(final String url) {
        // if the permitted hostnames have not been restricted to a specific set
        if (mPermittedHostnames.size() == 0) {
            // all hostnames are allowed
            return true;
        }
 
        // get the actual hostname of the URL that is to be checked
        final String actualHost = Uri.parse(url).getHost();
 
        // for every hostname in the set of permitted hosts
        for (String expectedHost : mPermittedHostnames) {
            // if the two hostnames match or if the actual host is a subdomain of the expected host
            if (actualHost.equals(expectedHost) || actualHost.endsWith("." + expectedHost)) {
                // the actual hostname of the URL to be checked is allowed
                return true;
            }
        }
 
        // the actual hostname of the URL to be checked is not allowed since there were no matches
        return false;
    }
 
    protected void setLastError() {
        mLastError = System.currentTimeMillis();
    }
 
    protected boolean hasError() {
        return (mLastError + 500) >= System.currentTimeMillis();
    }
 
    protected static String getLanguageIso3() {
        try {
            return Locale.getDefault().getISO3Language().toLowerCase(Locale.US);
        } catch (MissingResourceException e) {
            return LANGUAGE_DEFAULT_ISO3;
        }
    }
 
    /**
     * Provides localizations for the 25 most widely spoken languages that have a ISO 639-2/T code
     */
    protected String getFileUploadPromptLabel() {
        try {
            if (mLanguageIso3.equals("zho")) return decodeBase64("6YCJ5oup5LiA5Liq5paH5Lu2");
            else if (mLanguageIso3.equals("spa")) return decodeBase64("RWxpamEgdW4gYXJjaGl2bw==");
            else if (mLanguageIso3.equals("hin"))
                return decodeBase64("4KSP4KSVIOCkq+CkvOCkvuCkh+CksiDgpJrgpYHgpKjgpYfgpII=");
            else if (mLanguageIso3.equals("ben"))
                return decodeBase64("4KaP4KaV4Kaf4Ka/IOCmq+CmvuCmh+CmsiDgpqjgpr/gprDgp43gpqzgpr7gpprgpqg=");
            else if (mLanguageIso3.equals("ara"))
                return decodeBase64("2KfYrtiq2YrYp9ixINmF2YTZgSDZiNin2K3Yrw==");
            else if (mLanguageIso3.equals("por")) return decodeBase64("RXNjb2xoYSB1bSBhcnF1aXZv");
            else if (mLanguageIso3.equals("rus"))
                return decodeBase64("0JLRi9Cx0LXRgNC40YLQtSDQvtC00LjQvSDRhNCw0LnQuw==");
            else if (mLanguageIso3.equals("jpn"))
                return decodeBase64("MeODleOCoeOCpOODq+OCkumBuOaKnuOBl+OBpuOBj+OBoOOBleOBhA==");
            else if (mLanguageIso3.equals("pan"))
                return decodeBase64("4KiH4Kmx4KiVIOCoq+CovuCoh+CosiDgqJrgqYHgqKPgqYs=");
            else if (mLanguageIso3.equals("deu")) return decodeBase64("V8OkaGxlIGVpbmUgRGF0ZWk=");
            else if (mLanguageIso3.equals("jav")) return decodeBase64("UGlsaWggc2lqaSBiZXJrYXM=");
            else if (mLanguageIso3.equals("msa")) return decodeBase64("UGlsaWggc2F0dSBmYWls");
            else if (mLanguageIso3.equals("tel"))
                return decodeBase64("4LCS4LCVIOCwq+CxhuCxluCwsuCxjeCwqOCxgSDgsI7gsILgsJrgsYHgsJXgsYvgsILgsKHgsL8=");
            else if (mLanguageIso3.equals("vie"))
                return decodeBase64("Q2jhu41uIG3hu5l0IHThuq1wIHRpbg==");
            else if (mLanguageIso3.equals("kor"))
                return decodeBase64("7ZWY64KY7J2YIO2MjOydvOydhCDshKDtg50=");
            else if (mLanguageIso3.equals("fra"))
                return decodeBase64("Q2hvaXNpc3NleiB1biBmaWNoaWVy");
            else if (mLanguageIso3.equals("mar"))
                return decodeBase64("4KSr4KS+4KSH4KSyIOCkqOCkv+CkteCkoeCkvg==");
            else if (mLanguageIso3.equals("tam"))
                return decodeBase64("4K6S4K6w4K+BIOCuleCvh+CuvuCuquCvjeCuquCviCDgrqTgr4fgrrDgr43grrXgr4E=");
            else if (mLanguageIso3.equals("urd"))
                return decodeBase64("2KfbjNqpINmB2KfYptmEINmF24zauiDYs9uSINin2YbYqtiu2KfYqCDaqdix24zaug==");
            else if (mLanguageIso3.equals("fas"))
                return decodeBase64("2LHYpyDYp9mG2KrYrtin2Kgg2qnZhtuM2K8g24zaqSDZgdin24zZhA==");
            else if (mLanguageIso3.equals("tur")) return decodeBase64("QmlyIGRvc3lhIHNlw6dpbg==");
            else if (mLanguageIso3.equals("ita")) return decodeBase64("U2NlZ2xpIHVuIGZpbGU=");
            else if (mLanguageIso3.equals("tha"))
                return decodeBase64("4LmA4Lil4Li34Lit4LiB4LmE4Lif4Lil4LmM4Lir4LiZ4Li24LmI4LiH");
            else if (mLanguageIso3.equals("guj"))
                return decodeBase64("4KqP4KqVIOCqq+CqvuCqh+CqsuCqqOCrhyDgqqrgqrjgqoLgqqY=");
        } catch (Exception ignored) {
        }
 
        // return English translation by default
        return "Choose a file";
    }
 
    protected static String decodeBase64(final String base64) throws IllegalArgumentException, UnsupportedEncodingException {
        final byte[] bytes = Base64.decode(base64, Base64.DEFAULT);
        return new String(bytes, CHARSET_DEFAULT);
    }
 
    @SuppressLint("NewApi")
    protected void openFileInput(final ValueCallback<Uri> fileUploadCallbackFirst, final ValueCallback<Uri[]> fileUploadCallbackSecond, final boolean allowMultiple) {
        if (mFileUploadCallbackFirst != null) {
            mFileUploadCallbackFirst.onReceiveValue(null);
        }
        mFileUploadCallbackFirst = fileUploadCallbackFirst;
 
        if (mFileUploadCallbackSecond != null) {
            mFileUploadCallbackSecond.onReceiveValue(null);
        }
        mFileUploadCallbackSecond = fileUploadCallbackSecond;
 
        Intent i = new Intent(Intent.ACTION_GET_CONTENT);
        i.addCategory(Intent.CATEGORY_OPENABLE);
 
        if (allowMultiple) {
            if (Build.VERSION.SDK_INT >= 18) {
                i.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);
            }
        }
 
        i.setType(mUploadableFileTypes);
 
        if (mFragment != null && mFragment.get() != null && Build.VERSION.SDK_INT >= 11) {
            mFragment.get().startActivityForResult(Intent.createChooser(i, getFileUploadPromptLabel()), mRequestCodeFilePicker);
        } else if (mActivity != null && mActivity.get() != null) {
            mActivity.get().startActivityForResult(Intent.createChooser(i, getFileUploadPromptLabel()), mRequestCodeFilePicker);
        }
    }
 
    /**
     * Returns whether file uploads can be used on the current device (generally all platform versions except for 4.4)
     *
     * @return whether file uploads can be used
     */
    public static boolean isFileUploadAvailable() {
        return isFileUploadAvailable(false);
    }
 
    /**
     * Returns whether file uploads can be used on the current device (generally all platform versions except for 4.4)
     * <p/>
     * On Android 4.4.3/4.4.4, file uploads may be possible but will come with a wrong MIME type
     *
     * @param needsCorrectMimeType whether a correct MIME type is required for file uploads or `application/octet-stream` is acceptable
     * @return whether file uploads can be used
     */
    public static boolean isFileUploadAvailable(final boolean needsCorrectMimeType) {
        if (Build.VERSION.SDK_INT == 19) {
            final String platformVersion = (Build.VERSION.RELEASE == null) ? "" : Build.VERSION.RELEASE;
 
            return !needsCorrectMimeType && (platformVersion.startsWith("4.4.3") || platformVersion.startsWith("4.4.4"));
        } else {
            return true;
        }
    }
 
    /**
     * Handles a download by loading the file from `fromUrl` and saving it to `toFilename` on the external storage
     * <p/>
     * This requires the two permissions `android.permission.INTERNET` and `android.permission.WRITE_EXTERNAL_STORAGE`
     * <p/>
     * Only supported on API level 9 (Android 2.3) and above
     *
     * @param context    a valid `Context` reference
     * @param fromUrl    the URL of the file to download, e.g. the one from `AdvancedWebView.onDownloadRequested(...)`
     * @param toFilename the name of the destination file where the download should be saved, e.g. `myImage.jpg`
     * @return whether the download has been successfully handled or not
     */
    @SuppressLint("NewApi")
    public static boolean handleDownload(final Context context, final String fromUrl, final String toFilename) {
        if (Build.VERSION.SDK_INT < 9) {
            throw new RuntimeException("Method requires API level 9 or above");
        }
 
        final DownloadManager.Request request = new DownloadManager.Request(Uri.parse(fromUrl));
        if (Build.VERSION.SDK_INT >= 11) {
            request.allowScanningByMediaScanner();
            request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
        }
        request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, toFilename);
 
        final DownloadManager dm = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);
        try {
            try {
                dm.enqueue(request);
            } catch (SecurityException e) {
                if (Build.VERSION.SDK_INT >= 11) {
                    request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE);
                }
                dm.enqueue(request);
            }
 
            return true;
        }
        // if the download manager app has been disabled on the device
        catch (IllegalArgumentException e) {
            // show the settings screen where the user can enable the download manager app again
            openAppSettings(context, MyWebView.PACKAGE_NAME_DOWNLOAD_MANAGER);
 
            return false;
        }
    }
 
    @SuppressLint("NewApi")
    private static boolean openAppSettings(final Context context, final String packageName) {
        if (Build.VERSION.SDK_INT < 9) {
            throw new RuntimeException("Method requires API level 9 or above");
        }
 
        try {
            final Intent intent = new Intent(android.provider.Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
            intent.setData(Uri.parse("package:" + packageName));
            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
 
            context.startActivity(intent);
 
            return true;
        } catch (Exception e) {
            return false;
        }
    }
 
    /**
     * Wrapper for methods related to alternative browsers that have their own rendering engines
     */
    public static class Browsers {
 
        /**
         * Package name of an alternative browser that is installed on this device
         */
        private static String mAlternativePackage;
 
        /**
         * Returns whether there is an alternative browser with its own rendering engine currently installed
         *
         * @param context a valid `Context` reference
         * @return whether there is an alternative browser or not
         */
        public static boolean hasAlternative(final Context context) {
            return getAlternative(context) != null;
        }
 
        /**
         * Returns the package name of an alternative browser with its own rendering engine or `null`
         *
         * @param context a valid `Context` reference
         * @return the package name or `null`
         */
        public static String getAlternative(final Context context) {
            if (mAlternativePackage != null) {
                return mAlternativePackage;
            }
 
            final List<String> alternativeBrowsers = Arrays.asList(ALTERNATIVE_BROWSERS);
            final List<ApplicationInfo> apps = context.getPackageManager().getInstalledApplications(PackageManager.GET_META_DATA);
 
            for (ApplicationInfo app : apps) {
                if (!app.enabled) {
                    continue;
                }
 
                if (alternativeBrowsers.contains(app.packageName)) {
                    mAlternativePackage = app.packageName;
 
                    return app.packageName;
                }
            }
 
            return null;
        }
 
        /**
         * Opens the given URL in an alternative browser
         *
         * @param context a valid `Activity` reference
         * @param url     the URL to open
         */
        public static void openUrl(final Activity context, final String url) {
            openUrl(context, url, false);
        }
 
        /**
         * Opens the given URL in an alternative browser
         *
         * @param context           a valid `Activity` reference
         * @param url               the URL to open
         * @param withoutTransition whether to switch to the browser `Activity` without a transition
         */
        public static void openUrl(final Activity context, final String url, final boolean withoutTransition) {
            final Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(url));
            intent.setPackage(getAlternative(context));
            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
 
            context.startActivity(intent);
 
            if (withoutTransition) {
                context.overridePendingTransition(0, 0);
            }
        }
 
    }
    /*
    *
    * 获取Uri图片真实路径的方法
    * */
   public String getRealPathFromURI(Uri contentUri) {
        String res = null;
        String[] proj = {MediaStore.Images.Media.DATA};
        Cursor cursor = mContext.getContentResolver().query(contentUri, proj, null, null, null);
        if (cursor.moveToFirst()) {
            int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
            res = cursor.getString(column_index);
        }
        cursor.close();
        return res;
    }
}

若有不足之处，还请谅解指正，希望能帮到你…

源码来源地址 github：https://github.com/delight-im/Android-AdvancedWebView