Android 拍照选择图片并上传功能的实现思路(包含权限动态获取)

作为一个android新手，想实现手机拍照并上传的功能，经过查找资料，已实现此功能。在此记录备忘。老鸟请忽略。

一、实现思路：

1.android手机客户端，拍照(或选择图片)，然后上传到服务器。

2.服务器端接收手机端上传上来的图片。

二、实现步骤：

1.按惯例，先放效果图：

项目结构：

2.activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 android:orientation="vertical"
 android:padding="5dp">
 
 <textview
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="图片预览" />
 
 <imageview
 android:id="@+id/imageview"
 android:layout_width="match_parent"
 android:layout_height="400dp"
 android:background="#fff"
 android:padding="1dp"
 android:scaletype="fitxy" />
 
 <linearlayout
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:layout_gravity="center_horizontal"
 android:orientation="horizontal">
 
 <button
 android:id="@+id/btnphoto"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="拍照" />
 
 <button
 android:id="@+id/btnselect"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content"
 android:text="选择" />
 </linearlayout>
</linearlayout>

3.mainactivity.java

package com.qingshan.note;
import androidx.annotation.nonnull;
import androidx.annotation.requiresapi;
import androidx.appcompat.app.appcompatactivity;
import androidx.core.app.activitycompat;
import androidx.core.content.contextcompat;
import android.manifest;
import android.app.alertdialog;
import android.content.contentvalues;
import android.content.dialoginterface;
import android.content.intent;
import android.content.pm.packagemanager;
import android.graphics.bitmap;
import android.graphics.bitmapfactory;
import android.graphics.matrix;
import android.net.uri;
import android.os.build;
import android.os.bundle;
import android.os.environment;
import android.provider.mediastore;
import android.provider.settings;
import android.view.view;
import android.widget.button;
import android.widget.imageview;
import android.widget.toast;
import java.io.bufferedreader;
import java.io.datainputstream;
import java.io.dataoutputstream;
import java.io.file;
import java.io.fileinputstream;
import java.io.filenotfoundexception;
import java.io.fileoutputstream;
import java.io.ioexception;
import java.io.inputstreamreader;
import java.io.outputstream;
import java.net.httpurlconnection;
import java.net.url;
import java.text.simpledateformat;
import java.util.arraylist;
import java.util.date;
import java.util.hashmap;
import java.util.iterator;
import java.util.list;
import java.util.map;
public class mainactivity extends appcompatactivity implements view.onclicklistener {
 private button btnphoto, btnselect;
 private intent intent;
 private final int camera = 1;//事件枚举(可以自定义)
 private final int choose = 2;//事件枚举(可以自定义)
 private final string posturl = "http://qingshanboke.com/home/andoriduploadfile";//接收上传图片的地址
 string photopath = "";//要上传的图片路径
 private final int permissioncode = 100;//权限请求码
 //权限集合，对应在androidmanifest.xml文件中添加配置
 // <uses-permission android:name="android.permission.camera" />
 // <uses-permission android:name="android.permission.write_external_storage" />
 // <uses-permission android:name="android.permission.access_network_state" />
 // <uses-permission android:name="android.permission.access_wifi_state"/>
 // <uses-permission android:name="android.permission.internet"/>
 string[] permissions = new string[]{
 manifest.permission.camera,
 manifest.permission.write_external_storage,
 manifest.permission.access_network_state,
 manifest.permission.access_wifi_state,
 manifest.permission.internet
 };
 alertdialog alertdialog;
 @override
 protected void oncreate(bundle savedinstancestate) {
 super.oncreate(savedinstancestate);
 setcontentview(r.layout.activity_main);
 //6.0才用动态权限
 if (build.version.sdk_int >= 23) {
 checkpermission();
 }
 btnphoto = findviewbyid(r.id.btnphoto);
 btnselect = findviewbyid(r.id.btnselect);
 btnphoto.setonclicklistener(this);
 btnselect.setonclicklistener(this);
 }
 //检查权限
 private void checkpermission() {
 list<string> permissionlist = new arraylist<>();
 for (int i = 0; i < permissions.length; i++) {
 if (contextcompat.checkselfpermission(this, permissions[i]) != packagemanager.permission_granted) {
 permissionlist.add(permissions[i]);
 }
 }
 if (permissionlist.size() <= 0) {
 //说明权限都已经通过，可以做你想做的事情去
 } else {
 //存在未允许的权限
 activitycompat.requestpermissions(this, permissions, permissioncode);
 }
 }
 //授权后回调函数
 @override
 public void onrequestpermissionsresult(int requestcode, @nonnull string[] permissions, @nonnull int[] grantresults) {
 super.onrequestpermissionsresult(requestcode, permissions, grantresults);
 boolean haspermission = false;
 if (permissioncode == requestcode) {
 for (int i = 0; i < grantresults.length; i++) {
 if (grantresults[i] == -1) {
 haspermission = true;
 }
 }
 if (haspermission) {
 //跳转到系统设置权限页面，或者直接关闭页面，不让他继续访问
 permissiondialog();
 } else {
 //全部权限通过，可以进行下一步操作
 }
 }
 }
 //打开手动设置应用权限
 private void permissiondialog() {
 if (alertdialog == null) {
 alertdialog = new alertdialog.builder(this)
 .settitle("提示信息")
 .setmessage("当前应用缺少必要权限，该功能暂时无法使用。如若需要，请单击【确定】按钮前往设置中心进行权限授权。")
 .setpositivebutton("设置", new dialoginterface.onclicklistener() {
 @override
 public void onclick(dialoginterface dialog, int which) {
 cancelpermissiondialog();
 uri packageuri = uri.parse("package:" + getpackagename());
 intent intent = new intent(settings.action_application_details_settings, packageuri);
 startactivity(intent);
 }
 })
 .setnegativebutton("取消", new dialoginterface.onclicklistener() {
 @override
 public void onclick(dialoginterface dialog, int which) {
 cancelpermissiondialog();
 }
 })
 .create();
 }
 alertdialog.show();
 }
 //用户取消授权
 private void cancelpermissiondialog() {
 alertdialog.cancel();
 }
 @override
 public void onclick(view v) {
 switch (v.getid()) {
 //拍照按钮事件
 case r.id.btnphoto:
 //方法一：这样拍照只能取到缩略图（不清晰）
 //intent = new intent(android.provider.mediastore.action_image_capture);
 //startactivityforresult(intent, camera);
 //方法二：指定加载路径图片路径（保存原图，清晰）
 string sd_path = environment.getexternalstoragedirectory().getpath() + "/拍照上传示例/";
 simpledateformat format = new simpledateformat("yyyymmddhhmmss");
 string filename = format.format(new date(system.currenttimemillis())) + ".jpeg";
 photopath = sd_path + filename;
 file file = new file(photopath);
 if (!file.getparentfile().exists()) {
 file.getparentfile().mkdirs();
 }
 //兼容7.0以上的版本
 if (build.version.sdk_int >= build.version_codes.n) {
 try {
 contentvalues values = new contentvalues(1);
 values.put(mediastore.images.media.mime_type, "image/jpg");
 values.put(mediastore.images.media.data, photopath);
 uri tempuri = getcontentresolver().insert(mediastore.images.media.external_content_uri, values);
 intent intent = new intent(mediastore.action_image_capture);
 intent.addflags(intent.flag_grant_read_uri_permission | intent.flag_grant_write_uri_permission);
 if (tempuri != null) {
 intent.putextra(mediastore.extra_output, tempuri);
 intent.putextra(mediastore.extra_video_quality, 1);
 }
 startactivityforresult(intent, camera);
 } catch (exception e) {
 e.printstacktrace();
 }
 } else {
 intent = new intent(mediastore.action_image_capture);
 uri uri = uri.fromfile(file);
 intent.putextra(mediastore.extra_output, uri); //指定拍照后的存储路径，保存原图
 startactivityforresult(intent, camera);
 }
 break;
 //选择按钮事件
 case r.id.btnselect:
 intent = new intent(intent.action_pick, android.provider.mediastore.images.media.external_content_uri);
 startactivityforresult(intent, choose);
 break;
 }
 }
 @requiresapi(api = build.version_codes.o)
 @override
 protected void onactivityresult(int requestcode, int resultcode, intent data) {
 super.onactivityresult(requestcode, resultcode, data);
 switch (requestcode) {
 // 调用照相机拍照
 case camera:
 if (resultcode == result_ok) {
 //对应方法一：图片未保存，需保存文件到本地
// bundle bundle = data.getextras();
// bitmap bitmap = (bitmap) bundle.get("data");
// string savepath;
// string sd_path = environment.getexternalstoragedirectory().getpath() + "/拍照上传示例/";
// simpledateformat format = new simpledateformat("yyyymmddhhmmss");
// string filename = format.format(new date(system.currenttimemillis())) + ".jpeg";
// if (environment.getexternalstoragestate().equals(environment.media_mounted)) {
// savepath = sd_path;
// } else {
// toast.maketext(mainactivity.this, "保存失败！", toast.length_short).show();
// return;
// }
// photopath = savepath + filename;
// file file = new file(photopath);
// try {
// if (!file.exists()) {
// file.getparentfile().mkdirs();
// file.createnewfile();
// }
// fileoutputstream stream = new fileoutputstream(file);
// bitmap.compress(bitmap.compressformat.jpeg, 100, stream);
// toast.maketext(mainactivity.this, "保存成功,位置:" + file.getabsolutepath(), toast.length_short).show();
// } catch (ioexception e) {
// e.printstacktrace();
// }
 //对应方法二：图片已保存，只需读取就行了
 try {
 fileinputstream stream = new fileinputstream(photopath);
 bitmap bitmap = bitmapfactory.decodestream(stream);
 //预览图片
 imageview image = findviewbyid(r.id.imageview);
 image.setimagebitmap(bitmap);
 //上传图片（android 4.0 之后不能在主线程中请求http请求）
 file file = new file(photopath);
 if (file.exists()) {
 new thread(new runnable() {
 @override
 public void run() {
  //文本字段（用于验证用户身份）
  hashmap<string, string> form = new hashmap<string, string>();
  form.put("username", "zhangqs");
  form.put("password", "123456");
  //图片字段
  hashmap<string, string> file = new hashmap<string, string>();
  file.put(pathhelper.getfilenamefrompath(photopath), photopath);
  formupload(posturl, form, file);
 }
 }).start();
 }
 } catch (filenotfoundexception e) {
 e.printstacktrace();
 }
 }
 break;
 // 选择图片库的图片
 case choose:
 if (resultcode == result_ok) {
 try {
 uri uri = data.getdata();
 photopath = pathhelper.getrealpathfromuri(mainactivity.this, uri);
 bitmap bitmap = mediastore.images.media.getbitmap(this.getcontentresolver(), uri);
 //压缩图片
 bitmap = scalebitmap(bitmap, (float) 0.5);
 //预览图片
 imageview image = findviewbyid(r.id.imageview);
 image.setimagebitmap(bitmap);
 //上传图片（android 4.0 之后不能在主线程中请求http请求）
 file file = new file(photopath);
 if (file.exists()) {
 new thread(new runnable() {
 @override
 public void run() {
  //文本字段（用于验证用户身份）
  hashmap<string, string> form = new hashmap<string, string>();
  form.put("username", "zhangqs");
  form.put("password", "123456");
  //图片字段
  hashmap<string, string> file = new hashmap<string, string>();
  file.put(pathhelper.getfilenamefrompath(photopath), photopath);
  formupload(posturl, form, file);
 }
 }).start();
 }
 } catch (ioexception e) {
 e.printstacktrace();
 }
 }
 break;
 }
 }
 //压缩图片
 public bitmap scalebitmap(bitmap origin, float ratio) {
 if (origin == null) {
 return null;
 }
 int width = origin.getwidth();
 int height = origin.getheight();
 matrix matrix = new matrix();
 matrix.prescale(ratio, ratio);
 bitmap newbm = bitmap.createbitmap(origin, 0, 0, width, height, matrix, false);
 return newbm;
 }
 //post 表单提交
 @requiresapi(api = build.version_codes.o)
 public static string formupload(string posturl, map<string, string> textmap, map<string, string> filemap) {
 string res = "";
 httpurlconnection conn = null;
 string boundary = "---------------------------123821742118716"; //boundary就是request头和上传文件内容的分隔符
 try {
 url url = new url(posturl);
 conn = (httpurlconnection) url.openconnection();
 conn.setconnecttimeout(5000);
 conn.setreadtimeout(30000);
 conn.setdooutput(true);
 conn.setdoinput(true);
 conn.setusecaches(false);
 conn.setrequestmethod("post");
 conn.setrequestproperty("connection", "keep-alive");
 conn.setrequestproperty("user-agent", "mozilla/5.0 (windows; u; windows nt 6.1; zh-cn; rv:1.9.2.6)");
 conn.setrequestproperty("content-type", "multipart/form-data; boundary=" + boundary);
 outputstream out = new dataoutputstream(conn.getoutputstream());
 // text
 if (textmap != null) {
 stringbuffer buffer = new stringbuffer();
 iterator iter = textmap.entryset().iterator();
 while (iter.hasnext()) {
 map.entry entry = (map.entry) iter.next();
 string inputname = (string) entry.getkey();
 string inputvalue = (string) entry.getvalue();
 if (inputvalue == null) {
 continue;
 }
 buffer.append("\r\n").append("--").append(boundary).append("\r\n");
 buffer.append("content-disposition: form-data; name=\"" + inputname + "\"\r\n\r\n");
 buffer.append(inputvalue);
 }
 out.write(buffer.tostring().getbytes());
 }
 // file
 if (filemap != null) {
 iterator iter = filemap.entryset().iterator();
 while (iter.hasnext()) {
 map.entry entry = (map.entry) iter.next();
 string inputname = (string) entry.getkey();
 string inputvalue = (string) entry.getvalue();
 if (inputvalue == null) {
 continue;
 }
 file file = new file(inputvalue);
 string filename = file.getname();
 string contenttype = "";
 if (filename.endswith(".jpg")) {
 contenttype = "image/jpg";
 } else if (filename.endswith(".png")) {
 contenttype = "image/png";
 } else if (contenttype == null || contenttype.equals("")) {
 contenttype = "application/octet-stream";
 }
 stringbuffer buffer = new stringbuffer();
 buffer.append("\r\n").append("--").append(boundary).append("\r\n");
 buffer.append("content-disposition: form-data; name=\"" + inputname + "\"; filename=\"" + filename + "\"\r\n");
 buffer.append("content-type:" + contenttype + "\r\n\r\n");
 out.write(buffer.tostring().getbytes());
 datainputstream in = new datainputstream(new fileinputstream(file));
 int bytes = 0;
 byte[] bufferout = new byte[1024];
 while ((bytes = in.read(bufferout)) != -1) {
 out.write(bufferout, 0, bytes);
 }
 in.close();
 }
 }
 byte[] enddata = ("\r\n--" + boundary + "--\r\n").getbytes();
 out.write(enddata);
 out.flush();
 out.close();
 // 读取返回数据
 stringbuffer buffer = new stringbuffer();
 bufferedreader reader = new bufferedreader(new inputstreamreader(conn.getinputstream()));
 string line = null;
 while ((line = reader.readline()) != null) {
 buffer.append(line).append("\n");
 }
 res = buffer.tostring();
 reader.close();
 reader = null;
 } catch (exception e) {
 system.out.println("发送post请求出错。" + posturl);
 e.printstacktrace();
 } finally {
 if (conn != null) {
 conn.disconnect();
 conn = null;
 }
 }
 return res;
 }
}

4.辅助类 pathhelper.java

package com.qingshan.note;
import android.annotation.suppresslint;
import android.content.contenturis;
import android.content.context;
import android.database.cursor;
import android.net.uri;
import android.os.build;
import android.provider.documentscontract;
import android.provider.mediastore;
//android 路径辅助类
public class pathhelper {
 //适配api19以下(不包括api19),根据uri获取图片的绝对路径
 public static string getrealpathfromuri(context context, uri uri) {
 int sdkversion = build.version.sdk_int;
 if (sdkversion >= 19) { // api >= 19
 return getrealpathfromuriaboveapi19(context, uri);
 } else { // api < 19
 return getrealpathfromuribelowapi19(context, uri);
 }
 }
 /**
 * 适配api19以下(不包括api19),根据uri获取图片的绝对路径
 *
 * @param context 上下文对象
 * @param uri 图片的uri
 * @return 如果uri对应的图片存在, 那么返回该图片的绝对路径, 否则返回null
 */
 private static string getrealpathfromuribelowapi19(context context, uri uri) {
 return getdatacolumn(context, uri, null, null);
 }
 /**
 * 适配api19及以上,根据uri获取图片的绝对路径
 *
 * @param context 上下文对象
 * @param uri 图片的uri
 * @return 如果uri对应的图片存在, 那么返回该图片的绝对路径, 否则返回null
 */
 @suppresslint("newapi")
 private static string getrealpathfromuriaboveapi19(context context, uri uri) {
 string filepath = null;
 if (documentscontract.isdocumenturi(context, uri)) {
 // 如果是document类型的 uri, 则通过document id来进行处理
 string documentid = documentscontract.getdocumentid(uri);
 if (ismediadocument(uri)) { // mediaprovider
 // 使用':'分割
 string id = documentid.split(":")[1];
 string selection = mediastore.images.media._id + "=?";
 string[] selectionargs = {id};
 filepath = getdatacolumn(context, mediastore.images.media.external_content_uri, selection, selectionargs);
 } else if (isdownloadsdocument(uri)) { // downloadsprovider
 uri contenturi = contenturis.withappendedid(uri.parse("content://downloads/public_downloads"), long.valueof(documentid));
 filepath = getdatacolumn(context, contenturi, null, null);
 }
 } else if ("content".equalsignorecase(uri.getscheme())) {
 // 如果是 content 类型的 uri
 filepath = getdatacolumn(context, uri, null, null);
 } else if ("file".equals(uri.getscheme())) {
 // 如果是 file 类型的 uri,直接获取图片对应的路径
 filepath = uri.getpath();
 }
 return filepath;
 }
 private static string getdatacolumn(context context, uri uri, string selection, string[] selectionargs) {
 string path = null;
 string[] projection = new string[]{mediastore.images.media.data};
 cursor cursor = null;
 try {
 cursor = context.getcontentresolver().query(uri, projection, selection, selectionargs, null);
 if (cursor != null && cursor.movetofirst()) {
 int columnindex = cursor.getcolumnindexorthrow(projection[0]);
 path = cursor.getstring(columnindex);
 }
 } catch (exception e) {
 e.printstacktrace();
 } finally {
 if (cursor != null) {
 cursor.close();
 }
 }
 return path;
 }
 private static boolean ismediadocument(uri uri) {
 return "com.android.providers.media.documents".equals(uri.getauthority());
 }
 private static boolean isdownloadsdocument(uri uri) {
 return "com.android.providers.downloads.documents".equals(uri.getauthority());
 }
 //从路径中提取文件名
 public static string getfilenamefrompath(string path) {
 int start = path.lastindexof("/");
 int end = path.lastindexof(".");
 if (start != -1 && end != -1) {
 return path.substring(start + 1, end);
 } else {
 return null;
 }
 }
}

5.androidmanifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
 package="com.qingshan.note">
 <!-- 因为拍照需要写入文件 所以需要申请读取内存的权限 -->
 <uses-permission android:name="android.permission.camera" />
 <uses-permission android:name="android.permission.write_external_storage" />
 <uses-permission android:name="android.permission.access_network_state" />
 <uses-permission android:name="android.permission.access_wifi_state"/>
 <uses-permission android:name="android.permission.internet"/>
 <application
 android:networksecurityconfig="@xml/network_security_config"
 android:allowbackup="true"
 android:icon="@mipmap/ic_launcher"
 android:label="@string/app_name"
 android:usescleartexttraffic="true"
 android:roundicon="@mipmap/ic_launcher_round"
 android:supportsrtl="true"
 android:theme="@style/apptheme">
 <activity android:name=".mainactivity">
 <intent-filter>
 <action android:name="android.intent.action.main" />
 <category android:name="android.intent.category.launcher" />
 </intent-filter>
 </activity>
 </application>
</manifest>

6.\res\xml\network_security_config.xml

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
 <base-config cleartexttrafficpermitted="true" />
 <domain-config cleartexttrafficpermitted="true" >
 <domain includesubdomains="true">127.0.0.1</domain>
 <domain includesubdomains="true">192.168.100.192</domain>
 <domain includesubdomains="true">localhost</domain>
 <domain includesubdomains="true">qingshanboke.com</domain>
 </domain-config>
</network-security-config>

7.服务器端接收（asp.net mvc 接收）

       

public actionresult andoriduploadfile()
 {
 var username = request.params["username"];
 var password = request.params["password"];
 if (string.isnullorempty(username) || string.isnullorempty(password))
 {
 return content("抱歉，用户名和密码错误！");
 }
 //todo:身份验证
 
 var dir = pathhelper.getmappath("~/uploadfiles/" + datetime.now.tostring("yyyy-mm"));
 if (!directory.exists(dir))
 {
 directory.createdirectory(dir);
 }
 for (int i = 0; i < request.files.count; i++)
 {
 var path = path.combine(dir, datetime.now.tostring("yyyymmddhhmmss") + ".jpg");
 if (request.files[i] != null)
 {
 request.files[i].saveas(path);
 }
 }
 return content("{\"issuccess\":true}");
 }

三、注意事项

1.android发起http请求时，默认请求地址需https，需要增加 network-security-config 配置来允许使用http。（详见上面6.\res\xml\network_security_config.xml）

2.发起post提交时，往往需要做接口身份识别，需要将文本字段和图片字段一起提交，构造表单时，需要 "content-type", "multipart/form-data; boundary..."。

3.拍照时，默认只能取到缩略图，不够清晰，若要取到原图，需要在拍照时，传入指定保存位置，在回调函数中只需读取就可以了。

总结

以上所述是小编给大家介绍的android 拍照选择图片并上传功能的实现思路(包含权限动态获取)，希望对大家有所帮助