httpclient post 示例

HttpClient是一个在Java中用于HTTP客户端操作的库，常用于发送HTTP请求，包括POST方法。下面是一个简单的示例，展示如何使用Apache HttpClient库进行POST请求：

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 org.apache.http.util.EntityUtils;

public class HttpClientPostExample {
    public static void main(String[] args) throws Exception {
        // 创建HttpClient实例
        CloseableHttpClient httpClient = HttpClients.createDefault();

        try {
            // 创建HttpPost对象并设置URL
            HttpPost httpPost = new HttpPost("http://example.com/api/endpoint");

            // 设置POST数据
            String jsonContent = "{\"key\":\"value\"}";
            StringEntity inputEntity = new StringEntity(jsonContent);
            httpPost.setEntity(inputEntity);

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

            try {
                // 获取响应状态码
                int responseCode = response.getStatusLine().getStatusCode();
                System.out.println("Response Code : " + responseCode);

                // 如果成功，获取响应体作为字符串
                if (responseCode == 200) {
                    HttpEntity entity = response.getEntity();
                    String responseBody = EntityUtils.toString(entity);
                    System.out.println("Response Body : " + responseBody);
                } else {
                    System.err.println("Error posting data. Status code: " + responseCode);
                }
            } finally {
                // 关闭连接
                response.close();
            }
        } finally {
            // 最后关闭HttpClient
            httpClient.close();
        }
    }
}

在这个例子中，我们创建了一个`HttpPost`对象，并设置了目标URL以及POST的数据（这里是一个JSON字符串）。然后通过`HttpClient`执行请求，并处理响应结果。