HttpClient简单使用

1、创建HTTP客户端

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

2、发送基本的GET请求

　　instance.execute(new HttpGet(“http://www.baidu.com”));

3、获取HTTP响应的状态码

　　String url = “http://www.baidu.com”;
　　CloseableHttpResponse response = instance.execute(new HttpGet(url));
　　assertThat(response.getStatusLine().getStatusCode(), equalTo(200));
4、获取响应的媒体类型

　　String url = “http://www.baidu.com”;
　　CloseableHttpResponse response = instance.execute(new HttpGet(url));
　　String contentMimeType = ContentType.getOrDefault(response.getEntity()).getMimeType();
　　assertThat(contentMimeType, equalTo(ContentType.TEXT_HTML.getMimeType()));
5、获取响应的BODY部分

　　String url = “http://www.baidu.com”;
　　CloseableHttpResponse response = instance.execute(new HttpGet(url));
　　String bodyAsString = EntityUtils.toString(response.getEntity());
　　assertThat(bodyAsString, notNullValue());
6、配置请求的超时设置

　　@Test(expected=SocketTimeoutException.class)

　　public void givenLowTimeout_whenExecutingRequestWithTimeout_thenException() throws ClientProtocolException, IOException{
　　　　RequestConfig requestConfig = RequestConfig.custom() .setConnectionRequestTimeout(50).setConnectTimeout(50) .setSocketTimeout(50).build();
　　　　HttpGet request = new HttpGet(SAMPLE_URL);
　　　　request.setConfig(requestConfig);
　　　　instance.execute(request);
　　}

7、发送POST请求

　　instance.execute(new HttpPost(SAMPLE_URL));
8、为HTTP请求配置重定向

　　CloseableHttpClient instance = HttpClientBuilder.create().disableRedirectHandling().build();
　　CloseableHttpResponse response = instance.execute(new HttpGet(SAMPLE_URL));
　　assertThat(reponse.getStatusLine().getStatusCode(), equalTo(301));
9、配置请求的HEADER部分

　　HttpGet request = new HttpGet(SAMPLE_URL);
　　request.addHeader(HttpHeaders.ACCEPT, “application/xml”);
　　response = instance.execute(request);

10、获取响应的HEADER部分

　　CloseableHttpResponse response = instance.execute(new HttpGet(SAMPLE_URL));
　　Header[] headers = response.getHeaders(HttpHeaders.CONTENT_TYPE);
　　assertThat(headers, not(emptyArray()));
11、关闭或释放资源

　　response = instance.execute(new HttpGet(SAMPLE_URL));
　　try{
　　　　HttpEntity entity = response.getEntity();
　　　　if(entity!=null){
　　　　　　InputStream instream = entity.getContent();
　　　　　　instream.close();
　　　　}
　　} finally{
　　　　　　response.close();
　　}