apache-httpclient 快速使用

apache-httpclient 快速使用

HttpClient 是 Apache Jakarta Common下的子项目，用于提供高效的、最新的、功能丰富的支持HTTP协议的客户端编程工具包，支持 HTTP1.0 和 HTTP 1.1，支持 HTTP 的全部方法（GET，POST，PUT，DELETE 等）；

HttpClient 官网： http://hc.apache.org/httpcomponents-client-4.5.x/index.html

使用 HttpClient 需要导入以下依赖：

org.apache.httpcomponents:httpclient

发送 GET 请求

CloseableHttpClient httpclient = HttpClients.createDefault();  //构建默认HttpClient对象
HttpGet httpGet = new HttpGet("http://blog.csdn.net/");
//如果要设置发送头，可以通过 httpGet.setHeader(String name, String value) 方法

CloseableHttpResponse response = httpclient.execute(httpGet);  //执行HttpClinet，获取HttpResponse 对象

//获取响应状态行
System.out.println(response.getStatusLine());

//获取响应头
Header[] headers = response.getAllHeaders();
Arrays.stream(headers).forEach(System.out::println);

//获取响应实体
HttpEntity entity = response.getEntity();
System.out.println(entity.getContentLength());  //获取响应正文长度
//以字符流的方式读取响应正文
String content = new BufferedReader(new InputStreamReader(entity.getContent())).lines().collect(Collectors.joining("\n"));
System.out.println(content);

发送 POST 请求

//构建默认HttpClient对象
CloseableHttpClient httpClient = HttpClients.createDefault();

HttpPost httpPost = new HttpPost("http://127.0.0.1:8080/checkLogin");
//构建请求参数
Map params = new HashMap<>();
params.put("username","assad");
params.put("password","1234");
List formparams = new ArrayList<>();
for(Map.Entry entry : params.entrySet())
            formparams.add(new BasicNameValuePair(entry.getKey(),entry.getValue()));
UrlEncodedFormEntity encodedEntity = new UrlEncodedFormEntity(formparams, Consts.UTF_8);

httpPost.setEntity(encodedEntity);

//执行HttpClinet，获取HttpResponse 对象
CloseableHttpResponse response = httpClient.execute(httpPost);
//如果要设置发送头，可以通过 httpGet.setHeader(String name, String value) 方法

//获取响应状态行
System.out.println(response.getStatusLine());

//获取响应头
Header[] headers = response.getAllHeaders();
Arrays.stream(headers).forEach(System.out::println);

//获取响应实体
HttpEntity entity = response.getEntity();
System.out.println(entity.getContentLength());  //获取响应正文长度
 //以字符流的方式读取响应正文
String content = new BufferedReader(new InputStreamReader(entity.getContent())).lines().collect(Collectors.joining("\n"));
System.out.println(content);