什么是OKHttp

一般在Java平台上，我们会使用Apache HttpClient作为Http客户端，用于发送 HTTP 请求，并对响应进行处理。比如可以使用http客户端与第三方服务(如SSO服务)进行集成，当然还可以爬取网上的数据等。OKHttp与HttpClient类似，也是一个Http客户端，提供了对 HTTP/2 和 SPDY 的支持，并提供了连接池，GZIP 压缩和 HTTP 响应缓存功能；

官网：

添加依赖

在Java中使用OKHttp很简单，如果是maven工程，往pom.xml添加如下xml片段即可，目前最新版本2.7.5

         
      
       com.squareup.okhttp
          
      
       okhttp
          
      
       2.7.5
      
     

如果是gradle，添加如下依赖

compile group: 'com.squareup.okhttp', name: 'okhttp', version: '2.7.5'

 简单使用

后端Controller

一个简单的spring mvc web应用。

@RequestMapping(value = "/getUserList", produces = "application/json; charset=utf-8")    @ResponseBody    public String getUserList(int pageNo, int pageSize)    {        Map
     
       map = new HashMap
      
       ();        try        {            Map
       
         param = new HashMap
        
         ();            param.put("pageNo", pageNo);            param.put("pageSize", pageSize);            List
         
           userList = userService.queryAll(param);            map.put("userList", userList);            return gson.toJson(map);        }        catch (Exception e)        {            logger.error(e.toString(), e);        }        return gson.toJson(FAILD);    }
         
        
       
      
     

使用OkHttp发送Ge请求

package cn.hdu.edu.okhttpdemo;import java.io.IOException;import com.squareup.okhttp.OkHttpClient;import com.squareup.okhttp.Request;import com.squareup.okhttp.Response;/** * Hello world! * */public class App{    public String run(OkHttpClient client, String url) throws IOException {        Request request = new Request.Builder().url(url).build();        Response response = client.newCall(request).execute();        return response.body().string();      }    public static void main( String[] args )    {        OkHttpClient client = new OkHttpClient();        try        {            String res = new App().run(client, "http://localhost:8080/webbf/user/getUserList.do?pageNo=0&pageSize=10");            System.out.println(res);        }        catch (IOException e)        {            e.printStackTrace();        }    }}

使用OkHttp发送Post请求

package cn.hdu.edu.okhttpdemo;import java.io.IOException;import com.squareup.okhttp.FormEncodingBuilder;import com.squareup.okhttp.MediaType;import com.squareup.okhttp.OkHttpClient;import com.squareup.okhttp.Request;import com.squareup.okhttp.Response;/** * Hello world! * */public class App{    public static final MediaType JSON = MediaType.parse("application/json; charset=utf-8");    public String post(OkHttpClient client, String url) throws IOException    {        Request request = new Request.Builder()        .url(url)        .post(new FormEncodingBuilder()            .add("pageNo", "0")  //参数1            .add("pageSize", "10")  //参数二            .build())        .build();        Response response = client.newCall(request).execute();        return response.body().string();    }    public static void main(String[] args)    {        OkHttpClient client = new OkHttpClient();        try        {            String res = new App().post(client,                "http://localhost:8080/webbf/user/getUserList.do");            System.out.println(res);        }        catch (IOException e)        {            e.printStackTrace();        }    }}

结果打印

请求成功，打印以下数据：

{"userList":[{"id":49,"name":"876","address":"876"},{"id":50,"name":"antd","address":"antd"},{"id":51,"name":"sda","address":"sadsd"},{"id":52,"name":"5545","address":"4646546546"},{"id":53,"name":"sdas","address":"sdasa"},{"id":54,"name":"hggs","address":"sdsd"},{"id":55,"name":"4","address":"5"},{"id":56,"name":"4","address":"4"},{"id":57,"name":"00ba9d8e-0628-4477-857f-ef617c1ff4bc","address":"5906"},{"id":58,"name":"613ee3a3-fb87-4413-a8e0-9272d10ad4a7","address":"6427"}]}