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、封裝post請求方法

public static String httpPost(String url,Map map){
            // 返回body
            String body = null;
            // 獲取連線客戶端工具
            CloseableHttpClient httpClient = HttpClients.createDefault();
            CloseableHttpResponse httpResponse=null;
            // 2、建立一個HttpPost請求
            HttpPost post = new HttpPost(url);
            // 5、設定header資訊

　　　/**header中通用屬性*/
　　　　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");
　　　　/**業務引數*/
　　　　post.setHeader("test1","test1");
　　　　post.setHeader("test2",2);
　　

            // 設定引數
            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、執行post請求操作，並拿到結果
                    httpResponse = httpClient.execute(post);
                    // 獲取結果實體
                    HttpEntity entity = httpResponse.getEntity();
                    if (entity != null) {
                        // 按指定編碼轉換結果實體為String型別
                        body = EntityUtils.toString(entity, "UTF-8");
                    }
                    try {
                        httpResponse.close();
                        httpClient.close();
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
            return body;
}

3、封裝GET請求方法

public static String httpGet(String url){
    // 獲取連線客戶端工具
    CloseableHttpClient httpClient = HttpClients.createDefault();
    CloseableHttpResponse httpResponse=null;
    String finalString = null;
    HttpGet httpGet = new HttpGet(url);
    /**公共引數新增至httpGet*/

/**header中通用屬性*/
　　　　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");
　　　　/**業務引數*/
　　　　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、封裝put請求

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

    String encode = "utf-8";

    //HttpClients.createDefault()等價於 HttpClientBuilder.create().build();
    CloseableHttpClient closeableHttpClient = HttpClients.createDefault();
    HttpPut httpput = new HttpPut(url);
    // 5、設定header資訊

/**header中通用屬性*/
　　　　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");
　　　　/**業務引數*/
　　　　httpput.setHeader("test1","test1");
　　　　httpput.setHeader("test2",2);

    //組織請求引數
    StringEntity stringEntity = new StringEntity(JSON.toJSONString(map), encode);
    httpput.setEntity(stringEntity);
    String content = null;
    CloseableHttpResponse  httpResponse = null;
    try {
        //響應資訊
        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();  //關閉連線、釋放資源
    } catch (IOException e) {
        e.printStackTrace();
    }
    return content;
}

5、封裝delete請求

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、設定header資訊
    

/**header中通用屬性*/
　　　　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");
　　　　/**業務引數*/
　　　　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 {   //關閉連線、釋放資源
        closeableHttpClient.close();
    } catch (IOException e) {
        e.printStackTrace();
    }
    return content;
}