java使用httpcomponents post發送json數據

一、適用場景

　　當我們向第三方系統提交數據的時候，需要調用第三方系統提供的接口。不同的系統提供的接口也不一樣，有的是SOAP Webservice、RESTful Webservice 或其他的。當使用的是RESTful webservice的時候，就可以使用httpcomponents組件來完成調用。

　　如我們需要發起post請求，並將數據轉成json格式，設置到post請求中並提交。

　　url："http://www.xxxxx.com/message"

　　json數據格式 {"name":"zhangsan", "age":20, "gender": "mail"}   // 一個用戶的基本信息

二、實例代碼

 

package com.demo.test;

import java.io.IOException;

import org.apache.http.HttpEntity;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.ContentType;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class Test {

    public static String sendInfo(String sendurl, String data) {
        CloseableHttpClient client = HttpClients.createDefault();
        HttpPost post = new HttpPost(sendurl);
        StringEntity myEntity = new StringEntity(data,
                ContentType.APPLICATION_JSON);// 構造請求數據
        post.setEntity(myEntity);// 設置請求體
        String responseContent = null; // 響應內容
        CloseableHttpResponse response = null;
        try {
            response = client.execute(post);
            if (response.getStatusLine().getStatusCode() == 200) {
                HttpEntity entity = response.getEntity();
                responseContent = EntityUtils.toString(entity, "UTF-8");
            }
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (response != null)
                    response.close();

            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                try {
                    if (client != null)
                        client.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return responseContent;
    }

    public static void main(String[] args) {
        String json = "{\"name\":\"zhangsan\", \"age\":20, \"gender\": \"mail\"} ";
        String result = sendInfo("http://www.xxxxx.com/message", json);
        System.out.println(result);
    }
}

　　發送請求之后，后台會打印返回的信息。