java 发送post请求

Java发送POST请求可以使用HTTPClient库，下面是一个示例代码：

import org.apache.http.HttpEntity;
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.IOException;

public class HttpPostExample {

    public static void main(String[] args) throws IOException {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        HttpPost httpPost = new HttpPost("http://www.example.com/post");
        StringEntity requestEntity = new StringEntity(
                "{\"name\":\"value\"}",
                ContentType.APPLICATION_JSON);
        httpPost.setEntity(requestEntity);
        CloseableHttpResponse response = httpClient.execute(httpPost);
        try {
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                System.out.println(EntityUtils.toString(entity));
            }
        } finally {
            response.close();
        }
    }
}

这个示例代码使用HTTPClient库发送POST请求，请求的URL是http://www.example.com/post，请求体是一个JSON字符串。在发送请求之前，需要创建一个CloseableHttpClient对象，然后创建一个HttpPost对象，并设置请求体。发送请求后，可以通过CloseableHttpResponse对象获取响应结果。