java，http post请求，多个不同方式请求示例

以下是 Java 中进行 HTTP POST 请求的示例代码，包括使用 HttpURLConnection 和 HttpClient 两种方式，供您参考。
使用 HttpURLConnection 发送 POST 请求示例代码：

import java.io.BufferedReader;
import java.io.DataOutputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.nio.charset.StandardCharsets;
public class HttpPostWithHttpURLConnection {
    public static void main(String[] args) throws Exception {
        String url = "http://httpbin.org/post";
        String data = "name=value";
        URL obj = new URL(url);
        HttpURLConnection con = (HttpURLConnection) obj.openConnection();
        con.setRequestMethod("POST");
        con.setRequestProperty("User-Agent", "Mozilla/5.0");
        con.setRequestProperty("Accept-Language", "en-US,en;q=0.5");
        con.setDoOutput(true);
        try (DataOutputStream wr = new DataOutputStream(con.getOutputStream())) {
            wr.write(data.getBytes(StandardCharsets.UTF_8));
        }
        try (BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()))) {
            String line;
            StringBuilder response = new StringBuilder();
            while ((line = in.readLine()) != null) {
                response.append(line);
            }
            System.out.println(response.toString());
        }
    }
}

使用 HttpClient 发送 POST 请求示例代码：

import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
public class HttpPostWithHttpClient {
    public static void main(String[] args) throws Exception {
        String url = "http://httpbin.org/post";
        String data = "name=value";
        HttpPost httpPost = new HttpPost(url);
        httpPost.setHeader("Content-Type", "application/x-www-form-urlencoded");
        httpPost.setEntity(new StringEntity(data));
        try (CloseableHttpClient httpClient = HttpClients.createDefault();
             CloseableHttpResponse response = httpClient.execute(httpPost)) {
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                System.out.println(EntityUtils.toString(entity));
            }
        }
    }
}

需要注意的是，在实际使用中，需要根据具体需求设置请求头、请求参数等信息。另外，这里的示例代码中使用了 try-with-resources 语句来自动关闭资源，建议在实际使用中也使用这种方式来规避资源泄漏的风险。