怎么使用HttpClient和OkHttp

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使用

HttpClient和OkHttp一般用于调用其它服务，一般服务暴露出来的接口都为http，http常用请求类型就为GET、PUT、POST和DELETE，因此主要介绍这些请求类型的调用

HttpClient使用介绍

使用HttpClient发送请求主要分为以下几步骤：

• 创建 CloseableHttpClient对象或CloseableHttpAsyncClient对象，前者同步，后者为异步

• 创建Http请求对象

• 调用execute方法执行请求，如果是异步请求在执行之前需调用start方法

创建连接：

CloseableHttpClient httpClient = HttpClientBuilder.create().build();

该连接为同步连接

GET请求：

@Test  public void testGet() throws IOException {      String api = "/api/files/1";      String url = String.format("%s%s", BASE_URL, api);      HttpGet httpGet = new HttpGet(url);      CloseableHttpResponse response = httpClient.execute(httpGet);      System.out.println(EntityUtils.toString(response.getEntity()));  }

使用HttpGet表示该连接为GET请求，HttpClient调用execute方法发送GET请求

PUT请求：

@Test  public void testPut() throws IOException {      String api = "/api/user";      String url = String.format("%s%s", BASE_URL, api);      HttpPut httpPut = new HttpPut(url);      UserVO userVO = UserVO.builder().name("h3t").id(16L).build();      httpPut.setHeader("Content-Type", "application/json;charset=utf8");      httpPut.setEntity(new StringEntity(JSONObject.toJSONString(userVO), "UTF-8"));      CloseableHttpResponse response = httpClient.execute(httpPut);      System.out.println(EntityUtils.toString(response.getEntity()));  }

POST请求：

添加对象

@Test  public void testPost() throws IOException {      String api = "/api/user";      String url = String.format("%s%s", BASE_URL, api);      HttpPost httpPost = new HttpPost(url);      UserVO userVO = UserVO.builder().name("h3t2").build();      httpPost.setHeader("Content-Type", "application/json;charset=utf8");      httpPost.setEntity(new StringEntity(JSONObject.toJSONString(userVO), "UTF-8"));      CloseableHttpResponse response = httpClient.execute(httpPost);      System.out.println(EntityUtils.toString(response.getEntity()));  }

该请求是一个创建对象的请求，需要传入一个json字符串

上传文件

@Test  public void testUpload1() throws IOException {      String api = "/api/files/1";      String url = String.format("%s%s", BASE_URL, api);      HttpPost httpPost = new HttpPost(url);      File file = new File("C:/Users/hetiantian/Desktop/学习/docker_practice.pdf");      FileBody fileBody = new FileBody(file);      MultipartEntityBuilder builder = MultipartEntityBuilder.create();      builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);      builder.addPart("file", fileBody);  //addPart上传文件      HttpEntity entity = builder.build();      httpPost.setEntity(entity);      CloseableHttpResponse response = httpClient.execute(httpPost);      System.out.println(EntityUtils.toString(response.getEntity()));  }

通过addPart上传文件

DELETE请求：

@Test  public void testDelete() throws IOException {      String api = "/api/user/12";      String url = String.format("%s%s", BASE_URL, api);      HttpDelete httpDelete = new HttpDelete(url);      CloseableHttpResponse response = httpClient.execute(httpDelete);      System.out.println(EntityUtils.toString(response.getEntity()));  }

请求的取消：

@Test  public void testCancel() throws IOException {      String api = "/api/files/1";      String url = String.format("%s%s", BASE_URL, api);      HttpGet httpGet = new HttpGet(url);      httpGet.setConfig(requestConfig);  //设置超时时间      //测试连接的取消      long begin = System.currentTimeMillis();      CloseableHttpResponse response = httpClient.execute(httpGet);      while (true) {          if (System.currentTimeMillis() - begin > 1000) {            httpGet.abort();            System.out.println("task canceled");            break;        }      }      System.out.println(EntityUtils.toString(response.getEntity()));  }

调用abort方法取消请求 执行结果：

task canceled  cost 8098 msc  Disconnected from the target VM, address: '127.0.0.1:60549', transport: 'socket'  java.net.SocketException: socket closed...【省略】

OkHttp使用

使用OkHttp发送请求主要分为以下几步骤：

• 创建OkHttpClient对象

• 创建Request对象

• 将Request 对象封装为Call

• 通过Call 来执行同步或异步请求，调用execute方法同步执行，调用enqueue方法异步执行

创建连接：

private OkHttpClient client = new OkHttpClient();

GET请求：

@Test  public void testGet() throws IOException {      String api = "/api/files/1";      String url = String.format("%s%s", BASE_URL, api);      Request request = new Request.Builder()              .url(url)              .get()               .build();      final Call call = client.newCall(request);      Response response = call.execute();      System.out.println(response.body().string());  }

PUT请求：

@Test  public void testPut() throws IOException {      String api = "/api/user";      String url = String.format("%s%s", BASE_URL, api);      //请求参数      UserVO userVO = UserVO.builder().name("h3t").id(11L).build();      RequestBody requestBody = RequestBody.create(MediaType.parse("application/json; charset=utf-8"),      JSONObject.toJSONString(userVO));      Request request = new Request.Builder()              .url(url)              .put(requestBody)              .build();      final Call call = client.newCall(request);      Response response = call.execute();      System.out.println(response.body().string());  }

POST请求：

添加对象

@Test  public void testPost() throws IOException {      String api = "/api/user";      String url = String.format("%s%s", BASE_URL, api);      //请求参数      JSONObject json = new JSONObject();      json.put("name", "hetiantian");      RequestBody requestBody = RequestBody.create(MediaType.parse("application/json; charset=utf-8"),     String.valueOf(json));      Request request = new Request.Builder()             .url(url)              .post(requestBody) //post请求             .build();      final Call call = client.newCall(request);      Response response = call.execute();      System.out.println(response.body().string());  }

上传文件

@Test  public void testUpload() throws IOException {      String api = "/api/files/1";      String url = String.format("%s%s", BASE_URL, api);      RequestBody requestBody = new MultipartBody.Builder()              .setType(MultipartBody.FORM)              .addFormDataPart("file", "docker_practice.pdf",                      RequestBody.create(MediaType.parse("multipart/form-data"),                              new File("C:/Users/hetiantian/Desktop/学习/docker_practice.pdf")))              .build();      Request request = new Request.Builder()              .url(url)              .post(requestBody)  //默认为GET请求，可以不写              .build();      final Call call = client.newCall(request);      Response response = call.execute();      System.out.println(response.body().string());  }

通过addFormDataPart方法模拟表单方式上传文件

DELETE请求：

@Test  public void testDelete() throws IOException {    String url = String.format("%s%s", BASE_URL, api);    //请求参数    Request request = new Request.Builder()            .url(url)            .delete()            .build();    final Call call = client.newCall(request);    Response response = call.execute();    System.out.println(response.body().string());  }

请求的取消：

@Test  public void testCancelSysnc() throws IOException {      String api = "/api/files/1";      String url = String.format("%s%s", BASE_URL, api);      Request request = new Request.Builder()              .url(url)              .get()                .build();      final Call call = client.newCall(request);      Response response = call.execute();      long start = System.currentTimeMillis();      //测试连接的取消      while (true) {           //1分钟获取不到结果就取消请求          if (System.currentTimeMillis() - start > 1000) {              call.cancel();              System.out.println("task canceled");              break;          }      }      System.out.println(response.body().string());  }

调用cancel方法进行取消 测试结果：

task canceled  cost 9110 msc  java.net.SocketException: socket closed...【省略】

小结

OkHttp使用build模式创建对象来的更简洁一些，并且使用.post/.delete/.put/.get方法表示请求类型，不需要像HttpClient创建HttpGet、HttpPost等这些方法来创建请求类型

依赖包上，如果HttpClient需要发送异步请求、实现文件上传，需要额外的引入异步请求依赖

          org.apache.httpcomponents       httpmime       4.5.3                org.apache.httpcomponents       httpasyncclient       4.5.3   

请求的取消，HttpClient使用abort方法，OkHttp使用cancel方法，都挺简单的，如果使用的是异步client，则在抛出异常时调用取消请求的方法即可

超时设置

HttpClient超时设置：

在HttpClient4.3+版本以上，超时设置通过RequestConfig进行设置

private CloseableHttpClient httpClient = HttpClientBuilder.create().build();  private RequestConfig requestConfig =  RequestConfig.custom()          .setSocketTimeout(60 * 1000)          .setConnectTimeout(60 * 1000).build();  String api = "/api/files/1";  String url = String.format("%s%s", BASE_URL, api);  HttpGet httpGet = new HttpGet(url);  httpGet.setConfig(requestConfig);  //设置超时时间

超时时间是设置在请求类型HttpGet上，而不是HttpClient上

OkHttp超时设置：

直接在OkHttp上进行设置

private OkHttpClient client = new OkHttpClient.Builder()          .connectTimeout(60, TimeUnit.SECONDS)//设置连接超时时间          .readTimeout(60, TimeUnit.SECONDS)//设置读取超时时间          .build();

小结：

如果client是单例模式，HttpClient在设置超时方面来的更灵活，针对不同请求类型设置不同的超时时间，OkHttp一旦设置了超时时间，所有请求类型的超时时间也就确定

HttpClient和OkHttp性能比较

测试环境：

• CPU 六核

• 内存 8G

• windows10

每种测试用例都测试五次，排除偶然性

client连接为单例：

client连接不为单例：

单例模式下，HttpClient的响应速度要更快一些，单位为毫秒，性能差异相差不大

非单例模式下，OkHttp的性能更好，HttpClient创建连接比较耗时，因为多数情况下这些资源都会写成单例模式，因此图一的测试结果更具有参考价值

感谢各位的阅读，以上就是"怎么使用HttpClient和OkHttp"的内容了，经过本文的学习后，相信大家对怎么使用HttpClient和OkHttp这一问题有了更深刻的体会，具体使用情况还需要大家实践验证。这里是，小编将为大家推送更多相关知识点的文章，欢迎关注！