用Java代码实现发送post请求，RestTemplate发送post请求，Httpclient发送post请求

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestClientException;
import org.springframework.web.client.RestTemplate;



@Service
@Slf4j
public class TestServiceImpl implements TestService {

    @Autowired
    private RestTemplate restTemplate;

    private final String URL = "http://15.15.82.127:8124/api/test/getData";

    private final String USER_NAME = "test";

    private final String PASS_WORD = "test123";

第一种方法
//RestTemplate发送POST请求之带header，入参为json格式

@Override
    public String getData(){
        //1、构建body参数
        JSONObject jsonObject = new JSONObject();
        jsonObject.put("UserName",USER_NAME);
        jsonObject.put("Password",PASS_WORD);

        //2、添加请求头
        HttpHeaders headers = new HttpHeaders();
        headers.add("Content-Type","application/json");

        //3、组装请求头和参数
        HttpEntity formEntity = new HttpEntity(JSON.toJSONString(jsonObject), headers);

        //4、发起post请求
        ResponseEntity stringResponseEntity = null;
        try {
            stringResponseEntity = restTemplate.postForEntity(URL, formEntity, String.class);
            log.info("ResponseEntity----"+stringResponseEntity);
        } catch (RestClientException e) {
            e.printStackTrace();
        }

        //5、获取http状态码
        int statusCodeValue = stringResponseEntity.getStatusCodeValue();
        log.info("httpCode-----"+statusCodeValue);

        //6、获取返回体
        String body = stringResponseEntity.getBody();
        log.info("body-----"+body);

        //7、映射实体类
        Wrapper wrapper = JSONObject.parseObject(body, Wrapper.class);
        String data = wrapper.getData();
        log.info("data-----"+data);

        return data;
    }


第二种方法
//RestTemplate发送POST请求之formData形式
    @Override
    public String getData2(){
        MultiValueMap reqMap = new LinkedMultiValueMap<>();;
        reqMap.add("name","huhansan");
        reqMap.add("sex","man");
//.postForEntity(url,请求数据,返回数据类型)
        return restTemplate.postForEntity("http://localhost:8888/postwithpara", reqMap, String.class).getBody();

    }

}

restTemplate的详细用法可以见此链接 

    public void post(String url, Map params) {

        //创建httppost对象
        HttpPost post = new HttpPost(url);
        String paramStr = JSON.toJSONString(params);
        StringEntity stringEntity = new StringEntity(paramStr, StandardCharsets.UTF_8);

        //请求参数
        post.setEntity(stringEntity);

        //请求头
        post.setHeader("Content-Type", "application/json;charset=UTF-8");
        String msg = null;
        InetAddress ipaddr;
        try {

            //设置长/短连接 此处为短连接
            post.setHeader(HttpHeaders.CONNECTION, HTTP.CONN_CLOSE);

            //通过hostname获取本机ip地址
            ipaddr = InetAddress.getLocalHost();
            post.addHeader(new BasicHeader("API-RemoteIP", ipaddr.getHostAddress()));

            //创建httpclient对象发送post请求
            CloseableHttpClient httpClient = HttpClients.createDefault();
            CloseableHttpResponse resp = httpClient.execute(post);

            try {

                //返回信息
                HttpEntity entity = resp.getEntity();

                //获取请求状态码
                int statusCode = resp.getStatusLine().getStatusCode();
                if (entity != null) {
                    msg = EntityUtils.toString(entity);

                     //输出日志
                    logger.info("url:" + url + "参数：" + params.toString() + "返回信息：" + msg);
                }
                if (statusCode != 200 && statusCode != 302) {

                     //输出日志
                    logger.info("url:" + url + "失败信息：" + msg);
                }
            } finally {
                resp.close();
            }
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException(e.getMessage(), e);
        } finally {
            post.reset();
            post.releaseConnection();
        }
    }