Java 后台调用接口

网上找的HTTP 请求工具类

package com.spt.utils;

import org.apache.commons.io.IOUtils;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;

import javax.net.ssl.SSLContext;
import javax.net.ssl.TrustManager;
import javax.net.ssl.X509TrustManager;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.StandardCharsets;
import java.security.KeyManagementException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
import java.util.*;

/**
 * HTTP 请求工具类
 */
public class HttpUtils {
    private static PoolingHttpClientConnectionManager connMgr;
    private static RequestConfig requestConfig;
    private static final int MAX_TIMEOUT = 20000;

    static {
        // 设置连接池
        connMgr = new PoolingHttpClientConnectionManager();
        // 设置连接池大小
        connMgr.setMaxTotal(100);
        connMgr.setDefaultMaxPerRoute(connMgr.getMaxTotal());

        RequestConfig.Builder configBuilder = RequestConfig.custom();
        // 设置连接超时
        configBuilder.setConnectTimeout(MAX_TIMEOUT);
        // 设置读取超时
        configBuilder.setSocketTimeout(MAX_TIMEOUT);
        // 设置从连接池获取连接实例的超时
        configBuilder.setConnectionRequestTimeout(MAX_TIMEOUT);
        // 在提交请求之前 测试连接是否可用
//        configBuilder.setStaleConnectionCheckEnabled(true);
        requestConfig = configBuilder.build();
    }

    /**
     * 发送 GET 请求（HTTP），不带输入数据
     *
     * @param url
     * @param headers 需要添加的httpHeader参数
     * @return
     */
    public static String doGet(String url, Map<String, String> headers, Map<String, Object> params) {

        if (url.startsWith("https://")) {
            return doGetSSL(url, headers, params);
        } else {
            return doGetHttp(url, headers, params);
        }

    }

    /**
     * 发送 GET 请求（HTTP），K-V形式
     *
     * @param url
     * @param headers 需要添加的httpHeader参数
     * @param params
     * @return
     */
    public static String doGetHttp(String url, Map<String, String> headers, Map<String, Object> params) {
        //DefaultHttpClient() 过时了 换为HttpClientBuilder.create().build();
        //HttpClient httpclient = new DefaultHttpClient();
        HttpClient httpclient = HttpClientBuilder.create().build();
        String apiUrl = url;
        StringBuffer param = new StringBuffer();
        int i = 0;
        if (params != null) {
            for (String key : params.keySet()) {
                if (i == 0) {
                    param.append("?");
                } else {
                    param.append("&");
                }
                param.append(key).append("=").append(params.get(key));
                i++;
            }
            apiUrl += param;
        }
        String result = null;
        log("url: " + apiUrl);
        try {
            HttpGet httpGet = new HttpGet(apiUrl);
            // 添加http headers
            if (headers != null && headers.size() > 0) {
                for (String key : headers.keySet()) {
                    httpGet.addHeader(key, headers.get(key));
                }
            }

            HttpResponse response = httpclient.execute(httpGet);
            int statusCode = response.getStatusLine().getStatusCode();

            log("code : " + statusCode);

            HttpEntity entity = response.getEntity();
            if (entity != null) {
                InputStream instream = entity.getContent();
                result = IOUtils.toString(instream, StandardCharsets.UTF_8);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return result;
    }

    /**
     * 发送 SSL Get 请求（HTTPS），K-V形式
     *
     * @param url     API接口URL
     * @param headers
     * @param params  参数map
     * @return
     */
    public static String doGetSSL(String url, Map<String, String> headers, Map<String, Object> params) {
        CloseableHttpClient httpClient = HttpClients.custom().setSSLSocketFactory(createSSLConnSocketFactory())
                .setConnectionManager(connMgr).setDefaultRequestConfig(requestConfig).build();
        CloseableHttpResponse response = null;
        String apiUrl = url;
        String httpStr = null;
        StringBuffer param = new StringBuffer();
        if (params != null) {
            int i = 0;
            for (String key : params.keySet()) {
                if (i == 0) {
                    param.append("?");
                } else {
                    param.append("&");
                }
                param.append(key).append("=").append(params.get(key));
                i++;
            }
            apiUrl += param;
        }
        log("url: " + apiUrl);

        try {
            HttpGet httpGet = new HttpGet(apiUrl);
            httpGet.setConfig(requestConfig);
            // 添加http headers
            if (headers != null && headers.size() > 0) {
                for (String key : headers.keySet()) {
                    httpGet.addHeader(key, headers.get(key));
                }
            }
            response = httpClient.execute(httpGet);
            int statusCode = response.getStatusLine().getStatusCode();
            log("code : " + statusCode);
            if (statusCode != HttpStatus.SC_OK) {
                return null;
            }
            HttpEntity entity = response.getEntity();
            if (entity == null) {
                return null;
            }
            httpStr = EntityUtils.toString(entity, "utf-8");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (response != null) {
                try {
                    EntityUtils.consume(response.getEntity());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return httpStr;

    }

    /**
     * 发送 POST 请求（HTTP），K-V形式
     *
     * @param url
     * @param headers 需要添加的httpheader参数
     * @return
     */
    public static String doPostByForm(String url, Map<String, String> headers, Map<String, Object> params) {
        if (url.startsWith("https://")) {
            return doPostSSL(url, headers, params);
        } else {
            return doPostHttp(url, headers, params);
        }

    }

    /**
     * 发送 POST 请求（HTTP），JSON形式
     *
     * @param url
     * @param headers 需要添加的httpheader参数
     * @return
     */
    public static String doPostByJson(String url, Map<String, String> headers, Object json) {
        if (url.startsWith("https://")) {
            return doPostSSL(url, headers, json);
        } else {
            return doPostHttp(url, headers, json);
        }

    }

    /**
     * 发送 POST 请求（HTTP），K-V形式
     *
     * @param apiUrl  API接口URL
     * @param headers 需要添加的httpheader参数
     * @param params  参数map
     * @return
     */
    public static String doPostHttp(String apiUrl, Map<String, String> headers, Map<String, Object> params) {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        String httpStr = null;
        HttpPost httpPost = new HttpPost(apiUrl);
        CloseableHttpResponse response = null;
        if (headers != null) {
            Set<String> keys = headers.keySet();
            for (String key : keys) {
                httpPost.addHeader(key, headers.get(key));
            }
        }
        try {
            httpPost.setConfig(requestConfig);
            List<NameValuePair> pairList = new ArrayList<>(params.size());
            for (Iterator<Map.Entry<String, Object>> iterator = params.entrySet().iterator(); iterator.hasNext(); ) {
                Map.Entry<String, Object> entry = iterator.next();
                NameValuePair pair = new BasicNameValuePair(entry.getKey(), entry.getValue().toString());
                pairList.add(pair);
            }
            httpPost.setEntity(new UrlEncodedFormEntity(pairList, StandardCharsets.UTF_8));
            response = httpClient.execute(httpPost);
            log(response.toString());
            HttpEntity entity = response.getEntity();
            httpStr = EntityUtils.toString(entity, "UTF-8");
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (response != null) {
                try {
                    EntityUtils.consume(response.getEntity());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return httpStr;
    }

    /**
     * 发送 POST 请求（HTTP），JSON形式
     *
     * @param apiUrl
     * @param headers 需要添加的httpheader参数
     * @param json    json对象
     * @return
     */
    public static String doPostHttp(String apiUrl, Map<String, String> headers, Object json) {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        String httpStr = null;
        HttpPost httpPost = new HttpPost(apiUrl);
        CloseableHttpResponse response = null;
        if (headers != null) {
            Set<String> keys = headers.keySet();
            for (Iterator<String> i = keys.iterator(); i.hasNext(); ) {
                String key = i.next();
                httpPost.addHeader(key, headers.get(key));

            }
        }
        try {
            httpPost.setConfig(requestConfig);
            // 解决中文乱码问题
            StringEntity stringEntity = new StringEntity(json.toString(), "UTF-8");
            stringEntity.setContentEncoding("UTF-8");
            stringEntity.setContentType("application/json");
            httpPost.setEntity(stringEntity);
            response = httpClient.execute(httpPost);
            HttpEntity entity = response.getEntity();
            log(response.getStatusLine().getStatusCode() + "");
            httpStr = EntityUtils.toString(entity, "UTF-8");
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (response != null) {
                try {
                    EntityUtils.consume(response.getEntity());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return httpStr;
    }

    /**
     * 发送 SSL POST 请求（HTTPS），K-V形式
     *
     * @param apiUrl API接口URL
     * @param params 参数map
     * @return
     */
    public static String doPostSSL(String apiUrl, Map<String, String> headers, Map<String, Object> params) {
        CloseableHttpClient httpClient = HttpClients.custom().setSSLSocketFactory(createSSLConnSocketFactory())
                .setConnectionManager(connMgr).setDefaultRequestConfig(requestConfig).build();
        HttpPost httpPost = new HttpPost(apiUrl);
        CloseableHttpResponse response = null;
        String httpStr = null;
        if (headers != null) {
            Set<String> keys = headers.keySet();
            for (String key : keys) {
                httpPost.addHeader(key, headers.get(key));

            }
        }
        try {
            httpPost.setConfig(requestConfig);
            List<NameValuePair> pairList = new ArrayList<>(params.size());
            for (Map.Entry<String, Object> entry : params.entrySet()) {
                NameValuePair pair = new BasicNameValuePair(entry.getKey(), entry.getValue().toString());
                pairList.add(pair);
            }
            httpPost.setEntity(new UrlEncodedFormEntity(pairList, StandardCharsets.UTF_8));
            response = httpClient.execute(httpPost);
            int statusCode = response.getStatusLine().getStatusCode();
            if (statusCode != HttpStatus.SC_OK) {
                return null;
            }
            HttpEntity entity = response.getEntity();
            if (entity == null) {
                return null;
            }
            httpStr = EntityUtils.toString(entity, "utf-8");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (response != null) {
                try {
                    EntityUtils.consume(response.getEntity());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return httpStr;
    }

    /**
     * 发送 SSL POST 请求（HTTPS），JSON形式
     *
     * @param apiUrl API接口URL
     * @param json   JSON对象
     * @return
     */
    public static String doPostSSL(String apiUrl, Map<String, String> headers, Object json) {
        CloseableHttpClient httpClient = HttpClients.custom().setSSLSocketFactory(createSSLConnSocketFactory())
                .setConnectionManager(connMgr).setDefaultRequestConfig(requestConfig).build();
        HttpPost httpPost = new HttpPost(apiUrl);
        CloseableHttpResponse response = null;
        String httpStr = null;
        if (headers != null) {
            Set<String> keys = headers.keySet();
            for (String key : keys) {
                httpPost.addHeader(key, headers.get(key));

            }
        }
        try {
            httpPost.setConfig(requestConfig);
            StringEntity stringEntity = new StringEntity(json.toString(), "UTF-8");// 解决中文乱码问题
            stringEntity.setContentEncoding("UTF-8");
            stringEntity.setContentType("application/json");
            httpPost.setEntity(stringEntity);
            response = httpClient.execute(httpPost);
            int statusCode = response.getStatusLine().getStatusCode();
            if (statusCode != HttpStatus.SC_OK) {
                return null;
            }
            HttpEntity entity = response.getEntity();
            if (entity == null) {
                return null;
            }
            httpStr = EntityUtils.toString(entity, "utf-8");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (response != null) {
                try {
                    EntityUtils.consume(response.getEntity());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return httpStr;
    }

    /**
     * 创建SSL安全连接
     *
     * @return
     * @throws NoSuchAlgorithmException
     * @throws KeyManagementException
     */
    private static SSLConnectionSocketFactory createSSLConnSocketFactory() {
        // 创建TrustManager
        X509TrustManager xtm = new X509TrustManager() {
            @Override
            public void checkClientTrusted(X509Certificate[] chain, String authType) throws CertificateException {
            }

            @Override
            public void checkServerTrusted(X509Certificate[] chain, String authType) throws CertificateException {
            }

            @Override
            public X509Certificate[] getAcceptedIssuers() {
                return null;
            }
        };
        // TLS1.0与SSL3.0基本上没有太大的差别，可粗略理解为TLS是SSL的继承者，但它们使用的是相同的SSLContext
        SSLContext ctx;
        try {
            ctx = SSLContext.getInstance("TLS");
            // 使用TrustManager来初始化该上下文，TrustManager只是被SSL的Socket所使用
            ctx.init(null, new TrustManager[]{xtm}, null);
            SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(ctx);
            return sslsf;
        } catch (NoSuchAlgorithmException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (KeyManagementException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return null;
    }

    public static void log(String msg) {
        System.out.println(new Date() + "\t: " + msg);
    }

}

实现

    public void getStudentList() {
        Map<String, String> headers = new HashMap<>(); //头部
        headers.put("Authorization", "Bearer auth:token:xxxxxx");
        String url = "http://127.0.0.1:8008/getStudentInfo"; //请求url
        Map<String, Object> params = new HashMap<>(); //参数
        String studentResult = HttpUtils.doGet(url, headers, params);
        //将字符串转化 fastjson
        List<Student> studentList = (List<Student>) JSONObject.parse(studentResult);
    }

本文地址：https://blog.csdn.net/zmz200225/article/details/110847206