JAVA发送POST/GET/PUT/DELETE请求，HEADER传参，BODY参数为JSON格式

1、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>

2、封装post请求方法

public static String httpPost(String url,Map map){
            // 返回body
            String body = null;
            // 获取连接客户端工具
            CloseableHttpClient httpClient = HttpClients.createDefault();
            CloseableHttpResponse httpResponse=null;
            // 2、创建一个HttpPost请求
            HttpPost post = new HttpPost(url);
            // 5、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);

                    // 7、执行post请求操作，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;
}

3、封装GET请求方法

public static String httpGet(String url){
    // 获取连接客户端工具
    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;
}

4、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);
    // 5、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();  //关闭连接、释放资源
    } catch (IOException e) {
        e.printStackTrace();
    }
    return content;
}

5、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 不再使用 DefaultHttpClient
    CloseableHttpClient closeableHttpClient = HttpClientBuilder.create().build();
    HttpDelete httpdelete = new HttpDelete(url);
    // 5、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 {   //关闭连接、释放资源
        closeableHttpClient.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return content;
}