OkHttpClient 介绍

整体分为 5 步：

package com.maodou.autotest.utils; import okhttp3.Interceptor; import org.apache.http.client.HttpClient; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import okhttp3.*; import java.io.IOException; import java.net.SocketTimeoutException; import java.net.URLEncoder; import java.util.HashMap; import java.util.Iterator; import java.util.Map; import java.util.concurrent.TimeUnit; public class HttpClients { 
    / * 设置超时时间 */ private static final int CONNECT_TIMEOUT = 6; private static final int READ_TIMEOUT = 60; private static final int WRITE_TIMEOUT = 6; / * 设置编码集 */ private static final String ENCODE = "UTF-8"; / * public Builder() { * dispatcher = new Dispatcher(); * protocols = DEFAULT_PROTOCOLS; //默认支持的协议 * connectionSpecs = DEFAULT_CONNECTION_SPECS; //默认的连接规范 * proxySelector = ProxySelector.getDefault(); //默认的代理选择器，直连 * cookieJar = CookieJar.NO_COOKIES; //默认不进行管理Cookie * socketFactory = SocketFactory.getDefault(); * hostnameVerifier = OkHostnameVerifier.INSTANCE; //主机验证 * certificatePinner = CertificatePinner.DEFAULT; //证书锁，默认不开启 * proxyAuthenticator = Authenticator.NONE; //默认不进行授权 * authenticator = Authenticator.NONE; * connectionPool = new ConnectionPool(); //连接池 * dns = Dns.SYSTEM; * followSslRedirects = true; * followRedirects = true; * retryOnConnectionFailure = true; * //超时时间 * connectTimeout = 10_000; * readTimeout = 10_000; * writeTimeout = 10_000; * } */ public static String doGet(String url, String path, Map<String, Object> mapParams) { 
    String resultString = ""; Response response = null; try { 
    // 一、 创建 httpClient 对象* OkHttpClient httpClient = new OkHttpClient.Builder() .connectTimeout(CONNECT_TIMEOUT, TimeUnit.SECONDS) .readTimeout(READ_TIMEOUT, TimeUnit.SECONDS) .writeTimeout(WRITE_TIMEOUT, TimeUnit.SECONDS) .build(); String params = setUrlParams(mapParams); StringBuffer strinb = new StringBuffer(); strinb.append(url); strinb.append(path); strinb.append(params); // 二、创建request 对象* Request request = new Request.Builder() .url(strinb.toString()) .get() .build(); //* 三、发送请求  response = httpClient.newCall(request).execute(); //* 四、对响应进行处理 * //1、如果 http 状态码不在 【200 ，300】区间内，抛出异常 if (!response.isSuccessful()) { 
    throw new IOException("Unexpected code " + response); } // 因为服务器返回的数据可能非常大，所以必须通过数据流的方式来进行访问 // 提供了诸如 string() 和 bytes() 这样的方法将流内的数据一次性读取完毕 resultString = response.body().string(); return resultString; } catch (SocketTimeoutException e) { 
    // 超时 System.out.println("executeHttpRequest TimeOut, e: " + e); } catch (IOException e) { 
    // 网络IO异常 System.out.println("executeHttpRequest IOException, e: " + e); } catch (Exception e) { 
    // 其他异常 e.printStackTrace(); } finally { 
    if (response != null) { 
    // body 必须被关闭，否则会发生资源泄漏； response.body().close(); } } return resultString; } public static String doPost(String url, String path, Map<String, Object> mapParams){ 
    Response response = null; String resultString = ""; try{ 
    //* 一、创建 httpClient 对象  OkHttpClient httpClient = new OkHttpClient.Builder() .connectTimeout(CONNECT_TIMEOUT, TimeUnit.SECONDS) .readTimeout(READ_TIMEOUT, TimeUnit.SECONDS) .writeTimeout(WRITE_TIMEOUT, TimeUnit.SECONDS) .build(); StringBuffer stringB = new StringBuffer(); stringB.append(url); stringB.append(path); FormBody.Builder body = new FormBody.Builder(); for(Map.Entry<String,Object> entry : mapParams.entrySet()){ 
    body = new FormBody.Builder() .add(entry.getKey(), entry.getValue().toString()); } // 二、创建 request 对象  Request request = new Request.Builder() .url(stringB.toString()) .post(body.build()) .build(); // 三、执行请求  response = httpClient.newCall(request).execute(); // 四、处理响应  if(!response.isSuccessful()){ 
    throw new IOException( " Unexpect code " + response); } resultString = response.body().string(); }catch (SocketTimeoutException e) { 
    // 超时 System.out.println("executeHttpRequest TimeOut, e: " + e); } catch (IOException e) { 
    // 网络IO异常 System.out.println("executeHttpRequest IOException, e: " + e); } catch (Exception e) { 
    // 其他异常 e.printStackTrace(); } finally { 
    if (response != null) { 
    // body 必须被关闭，否则会发生资源泄漏； response.body().close(); } } return resultString; } public static String setUrlParams(Map<String, Object> mapParams) { 
    // 是否已经设置了问号 boolean hasSetQuestionMark = false; StringBuffer strParams = new StringBuffer(""); if (mapParams != null) { 
    Iterator<String> iterator = mapParams.keySet().iterator(); String key = ""; while (iterator.hasNext()) { 
    try { 
    key = iterator.next().toString(); if (!hasSetQuestionMark) { 
    strParams.append("?").append(key).append("=") .append(URLEncoder.encode(mapParams.get(key).toString(), "utf-8")); hasSetQuestionMark = true; continue; } strParams.append("&").append(key).append("=") .append(URLEncoder.encode(mapParams.get(key).toString(), "utf-8")); } catch (Exception e) { 
    e.printStackTrace(); } } } return strParams.toString(); } public static void main(String[] args){ 
    Map<String, Object> getParams = new HashMap<>(); Map<String, Object> postParams = new HashMap<>(); getParams.put("word", "%E4%BD%A0%E5%A5%BD"); postParams.put("url","/search"); String result1 = doGet("http://wenku.baidu.com", "/search/interface/getrelatequery", getParams); System.out.println(result1); String result2 = doPost("http://wenku.baidu.com", "/message/getnotice", postParams); System.out.println(result2); } }