java代码：

import org.apache.http.HttpEntity;
import org.apache.http.client.ClientProtocolException;
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.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import java.io.IOException;
public class DoPostWithBody {
    public static String doPostBody(String url, String paramString) {
        CloseableHttpClient httpClient = null;
        CloseableHttpResponse httpResponse = null;
        String result = "";
        httpClient = HttpClients.createDefault();
        HttpPost httpPost = new HttpPost(url);
        // 配置请求参数实例
        RequestConfig requestConfig = RequestConfig.custom().setConnectTimeout(35000)// 设置连接主机服务超时时间
                .setConnectionRequestTimeout(35000)// 设置连接请求超时时间
                .setSocketTimeout(60000)// 设置读取数据连接超时时间
                .build();
        // 为httpPost实例设置配置
        httpPost.setConfig(requestConfig);
        // 设置请求头
        httpPost.addHeader("Content-Type", "application/json");
        // 为httpPost设置封装好的请求参数
        try {
            httpPost.setEntity(new StringEntity(paramString, "UTF-8"));
        } catch (Exception e) {
            e.printStackTrace();
        }
        try {
            // httpClient对象执行post请求,并返回响应参数对象
            httpResponse = httpClient.execute(httpPost);
            // 从响应对象中获取响应内容
            HttpEntity entity = httpResponse.getEntity();
            result = EntityUtils.toString(entity);
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 关闭资源
            if (null != httpResponse) {
                try {
                    httpResponse.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (null != httpClient) {
                try {
                    httpClient.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return result;
    }
}

默认参数为两个字符串，请求地址和body字符串，返回类型为JSON字符串。