java jdk1.6 post请求 json对象放body中传递， 接收方从body中获取并输出 demo

在Java JDK 1.6版本中，发送POST请求并携带JSON数据通常使用HTTP客户端库如Apache HttpClient或者更现代的HttpURLConnection。以下是一个简单的示例，展示如何通过HttpClient发送POST请求，将JSON对象作为Body内容：

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

public class PostJsonExample {
    private static final String JSON_OBJECT = "{\"key\":\"value\"}";

    public void sendPostRequest() throws IOException {
        CloseableHttpClient httpClient = HttpClients.createDefault();
        try {
            HttpPost httpPost = new HttpPost("http://example.com/api endpoint"); // 替换为你实际的API地址

            // 将JSON转换为StringEntity
            HttpEntity entity = new StringEntity(JSON_OBJECT, "application/json");
            httpPost.setEntity(entity);

            // 发送请求
            CloseableHttpResponse response = httpClient.execute(httpPost);

            // 检查响应状态码
            int responseCode = response.getStatusLine().getStatusCode();
            if (responseCode == 200) {
                System.out.println("Received response:");
                // 读取并打印响应体
                HttpEntity respEntity = response.getEntity();
                if (respEntity != null) {
                    System.out.println(EntityUtils.toString(respEntity));
                } else {
                    System.out.println("No content received.");
                }
            } else {
                System.err.println("Failed with status code: " + responseCode);
            }

        } finally {
            httpClient.close();
        }
    }

    public static void main(String[] args) {
        try {
            PostJsonExample example = new PostJsonExample();
            example.sendPostRequest();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

在这个例子中，`sendPostRequest`方法会向指定URL发送POST请求，并附带JSON对象。接收端（服务器端）需要解析请求体（即body部分），一般可以使用类似Spring框架的`org.springframework.web.bind.annotation.PostMapping`注解处理JSON请求。