@Controller
@RequestMapping("/client")
public class TestController {

    private static final String urlStream = "http://127.0.0.1:8080/MyProject/nezha/getUserStream";

    @RequestMapping(value = "/getUserStream", method = RequestMethod.POST)
    @ResponseBody
    public User getUserStream(@RequestBody User user) {
        System.out.println("請(qǐng)求參數(shù)："+user);
        String userRet = HttpUtil.sendPostByURLConnection(urlStream, user);
        User ret = JSON.toJavaObject(JSONObject.parseObject(userRet), User.class);
        System.out.println("URLConnection方式發(fā)送POST請(qǐng)求："+ret);
        return ret;
    }
}

@Controller
@RequestMapping("/server")
public class PostServerController {

    @RequestMapping(value = "/getUserStream", method = RequestMethod.POST)
    @ResponseBody
    public User getUserStream(HttpServletRequest request) throws IOException {
        String user = IOUtils.toString(request.getInputStream(), StandardCharsets.UTF_8);
        User user1 = JSON.toJavaObject(JSONObject.parseObject(user), User.class);
        user1.setInfo("getUserStream，我 OK 啦");
        System.out.println(user1);
        return user1;
    }
}

@Controller
@RequestMapping("/client")
public class TestController {

    private static final String url = "http://127.0.0.1:8080/MyProject/nezha/getUser";

    @RequestMapping(value = "/getUser", method = RequestMethod.POST)
    @ResponseBody
    public User getUser(@RequestBody User user) {
        System.out.println("請(qǐng)求參數(shù)："+user);
        String json = JSON.toJSONString(user);
        String userRet = HttpUtil.sendHttpPost(url, json);
        User ret = JSON.toJavaObject(JSONObject.parseObject(userRet), User.class);
        System.out.println("HttpPost方式發(fā)送POST請(qǐng)求："+ret);
        return ret;
    }
}

@Controller
@RequestMapping("/server")
public class PostServerController {

    @RequestMapping(value = "/getUser", method = RequestMethod.POST)
    @ResponseBody
    public User getUser(@RequestBody User user) {
        user.setInfo("getUser，我 OK 啦");
        System.out.println(user);
        return user;
    }
}

import org.apache.http.client.config.RequestConfig;
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;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.URL;
import java.net.URLConnection;

public class HttpUtil {
    /**
     * URLConnection方式
     * 發(fā)送POST請(qǐng)求
     */
    public static <T> String sendPostByURLConnection(String url, T entity) {
        PrintWriter out = null;
        BufferedReader in = null;
        String result = "";
        try {
            URL realUrl = new URL(url);
            // 打開(kāi)和URL之間的連接
            URLConnection conn = realUrl.openConnection();
            // 設(shè)置通用的請(qǐng)求屬性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            // 設(shè)置請(qǐng)求類(lèi)型
            //conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            conn.setRequestProperty("Content-Type", "application/json");
            // 發(fā)送POST請(qǐng)求必須設(shè)置如下兩行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 獲取URLConnection對(duì)象對(duì)應(yīng)的輸出流
            out = new PrintWriter(conn.getOutputStream());
            // 發(fā)送請(qǐng)求參數(shù)
            out.print(entity);
            // flush輸出流的緩沖
            out.flush();
            // 定義BufferedReader輸入流來(lái)讀取URL的響應(yīng)
            in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result += line;
            }
        } catch (Exception e) {
            System.out.println(e);
            return null;
        }
        //使用finally塊來(lái)關(guān)閉輸出流、輸入流
        finally {
            try {
                if (out != null) {
                    out.close();
                }
                if (in != null) {
                    in.close();
                }
            } catch (IOException ex) {
            }
        }
        return result;
    }

    /**
     * HttpPost方式
     * 發(fā)送POST請(qǐng)求
     */
    public static String sendHttpPost(String url, String data) {
        String response = null;
        try {
            CloseableHttpClient httpclient = null;
            CloseableHttpResponse httpresponse = null;
            try {
                httpclient = HttpClients.createDefault();
                HttpPost httppost = new HttpPost(url);
                RequestConfig requestConfig = RequestConfig.custom()
                        .setConnectTimeout(5000)  //連接超時(shí)時(shí)間
                        .setSocketTimeout(5000)   //讀取數(shù)據(jù)超時(shí)時(shí)間
                        .build();
                httppost.setConfig(requestConfig);
                StringEntity stringentity = new StringEntity(data, ContentType.create("application/json", "UTF-8"));
                httppost.setEntity(stringentity);
                httpresponse = httpclient.execute(httppost);
                response = EntityUtils.toString(httpresponse.getEntity());
            } finally {
                if (httpclient != null) {
                    httpclient.close();
                }
                if (httpresponse != null) {
                    httpresponse.close();
                }
            }
        } catch (Exception e) {
            return null;
        }
        return response;
    }
}