OkHttp简介
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:http://square.github.io/okhttp/
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
<dependency> <groupId>com.squareup.okhttp</groupId> <artifactId>okhttp</artifactId> <version>2.7.5</version> </dependency>
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<String, Object> map = new HashMap<String, Object>(); try { Map<String, Object> param = new HashMap<String, Object>(); param.put("pageNo", pageNo); param.put("pageSize", pageSize); List<User> 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"}]}