java发送POST/GET/PUT/DELETE请求，header传参，body参数为json格式

一、maven引入

<dependency>
 <groupId>org.apache.httpcomponents</groupId>
 <artifactId>httpclient</artifactId>
 <version>4.5</version>
</dependency>

<dependency>
 <groupId>org.apache.httpcomponents</groupId>
 <artifactId>httpcore</artifactId>
 <version>4.4.4</version>
</dependency>

<dependency>
 <groupId>org.apache.httpcomponents</groupId>
 <artifactId>httpmime</artifactId>
 <version>4.5</version>
</dependency>

二、封装post请求方法

public static String httpPost(String url,Map map){
 // 返回body
 String body = null;
 // 获取链接客户端工具
 CloseableHttpClient httpClient = HttpClients.createDefault();
 CloseableHttpResponse httpResponse=null;
 // 二、建立一个HttpPost请求
 HttpPost post = new HttpPost(url);
 // 五、设置header信息

　　　/**header中通用属性*/
　　　　post.setHeader("Accept","*/*");
　　　　post.setHeader("Accept-Encoding","gzip, deflate");
　　　　post.setHeader("Cache-Control","no-cache");
　　　　post.setHeader("Connection", "keep-alive");
　　　　post.setHeader("Content-Type", "application/json;charset=UTF-8");
　　　　/**业务参数*/
　　　　post.setHeader("test1","test1");
　　　　post.setHeader("test2",2);
　　

 // 设置参数
 if (map != null) {
 
 //System.out.println(JSON.toJSONString(map));
 try {
 StringEntity entity1=new StringEntity(JSON.toJSONString(map),"UTF-8");
 entity1.setContentEncoding("UTF-8");
 entity1.setContentType("application/json");
 post.setEntity(entity1);

 // 七、执行post请求操做，并拿到结果
 httpResponse = httpClient.execute(post);
 // 获取结果实体
 HttpEntity entity = httpResponse.getEntity();
 if (entity != null) {
 // 按指定编码转换结果实体为String类型
 body = EntityUtils.toString(entity, "UTF-8");
 }
 try {
 httpResponse.close();
 httpClient.close();
 } catch (IOException e) {
 e.printStackTrace();
 }
 } catch (Exception e) {
 e.printStackTrace();
 }
 }
 return body;
}

三、封装GET请求方法

public static String httpGet(String url){
 // 获取链接客户端工具
 CloseableHttpClient httpClient = HttpClients.createDefault();
 CloseableHttpResponse httpResponse=null;
 String finalString = null;
 HttpGet httpGet = new HttpGet(url);
 /**公共参数添加至httpGet*/

/**header中通用属性*/
　　　　httpGet.setHeader("Accept","*/*");
　　　　httpGet.setHeader("Accept-Encoding","gzip, deflate");
　　　　httpGet.setHeader("Cache-Control","no-cache");
　　　　httpGet.setHeader("Connection", "keep-alive");
　　　　httpGet.setHeader("Content-Type", "application/json;charset=UTF-8");
　　　　/**业务参数*/
　　　　httpGet.setHeader("test1","test1");
　　　　httpGet.setHeader("test2",2);

 try {
 httpResponse = httpClient.execute(httpGet);
 HttpEntity entity = httpResponse.getEntity();
 finalString= EntityUtils.toString(entity, "UTF-8");
 try {
 httpResponse.close();
 httpClient.close();
 } catch (IOException e) {
 e.printStackTrace();
 }
 } catch (IOException e) {
 e.printStackTrace();
 }
 return finalString;
}

四、封装put请求

public static String httpPut(String url,Map map){

 String encode = "utf-8";

 //HttpClients.createDefault()等价于 HttpClientBuilder.create().build();
 CloseableHttpClient closeableHttpClient = HttpClients.createDefault();
 HttpPut httpput = new HttpPut(url);
 // 五、设置header信息

/**header中通用属性*/
　　　　httpput.setHeader("Accept","*/*");
　　　　httpput.setHeader("Accept-Encoding","gzip, deflate");
　　　　httpput.setHeader("Cache-Control","no-cache");
　　　　httpput.setHeader("Connection", "keep-alive");
　　　　httpput.setHeader("Content-Type", "application/json;charset=UTF-8");
　　　　/**业务参数*/
　　　　httpput.setHeader("test1","test1");
　　　　httpput.setHeader("test2",2);

 //组织请求参数
 StringEntity stringEntity = new StringEntity(JSON.toJSONString(map), encode);
 httpput.setEntity(stringEntity);
 String content = null;
 CloseableHttpResponse httpResponse = null;
 try {
 //响应信息
 httpResponse = closeableHttpClient.execute(httpput);
 HttpEntity entity = httpResponse.getEntity();
 content = EntityUtils.toString(entity, encode);
 } catch (Exception e) {
 e.printStackTrace();
 }finally{
 try {
 httpResponse.close();
 } catch (IOException e) {
 e.printStackTrace();
 }
 }
 try {
 closeableHttpClient.close(); //关闭链接、释放资源
 } catch (IOException e) {
 e.printStackTrace();
 }
 return content;
}

五、封装delete请求

public static String httpDelete(String url){

 //HttpResponse response = new HttpResponse();

 String encode = "utf-8";

 String content = null;
 //since 4.3 再也不使用 DefaultHttpClient
 CloseableHttpClient closeableHttpClient = HttpClientBuilder.create().build();
 HttpDelete httpdelete = new HttpDelete(url);
 // 五、设置header信息
 

/**header中通用属性*/
　　　　httpdelete.setHeader("Accept","*/*");
　　　　httpdelete.setHeader("Accept-Encoding","gzip, deflate");
　　　　httpdelete.setHeader("Cache-Control","no-cache");
　　　　httpdelete.setHeader("Connection", "keep-alive");
　　　　httpdelete.setHeader("Content-Type", "application/json;charset=UTF-8");
　　　　/**业务参数*/
　　　　httpdelete.setHeader("test1","test1");
　　　　httpdelete.setHeader("test2",2);

 CloseableHttpResponse httpResponse = null;
 try {
 httpResponse = closeableHttpClient.execute(httpdelete);
 HttpEntity entity = httpResponse.getEntity();
 content = EntityUtils.toString(entity, encode);

 } catch (Exception e) {
 e.printStackTrace();
 }finally{
 try {
 httpResponse.close();
 } catch (IOException e) {
 e.printStackTrace();
 }
 }
 try { //关闭链接、释放资源
 closeableHttpClient.close();
 } catch (IOException e) {
 e.printStackTrace();
 }
 return content;}