给我一个Java发送POST请求的模板

### 回答1：
以下是 Java 发送 POST 请求的简单模板代码：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class Main {
    public static void main(String[] args) throws IOException {
        URL url = new URL("https://www.example.com");
        HttpURLConnection con = (HttpURLConnection) url.openConnection();
        con.setRequestMethod("POST");
        con.setDoOutput(true);
        con.setDoInput(true);
        con.setRequestProperty("Content-Type", "application/json");

        String body = "{\"key\":\"value\"}";
        OutputStream os = con.getOutputStream();
        os.write(body.getBytes());
        os.flush();
        os.close();

        int responseCode = con.getResponseCode();
        System.out.println("Response code: " + responseCode);

        BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
        String inputLine;
        StringBuilder response = new StringBuilder();
        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
        in.close();

        System.out.println("Response body: " + response.toString());
    }
}

注意：请根据自己的需求修改 URL、请求头、请求体等内容。

### 回答2：
给你一个Java发送POST请求的模板：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class PostRequestExample {

    public static void main(String[] args) {
        try {
            // 设置请求URL和参数
            String url = "http://example.com/api/endpoint";
            String parameters = "param1=value1&param2=value2";

            // 创建URL对象
            URL obj = new URL(url);
            // 打开连接
            HttpURLConnection con = (HttpURLConnection) obj.openConnection();

            // 设置请求方法为POST
            con.setRequestMethod("POST");
            // 允许输入输出流
            con.setDoOutput(true);

            // 设置请求体参数
            OutputStream os = con.getOutputStream();
            os.write(parameters.getBytes("UTF-8"));
            os.flush();
            os.close();

            // 获取响应状态码
            int responseCode = con.getResponseCode();
            
            // 读取响应内容
            BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
            String inputLine;
            StringBuilder response = new StringBuilder();
            
            while ((inputLine = in.readLine()) != null) {
                response.append(inputLine);
            }
            in.close();
            
            // 输出响应结果
            System.out.println("响应状态码: " + responseCode);
            System.out.println("响应内容:\n" + response.toString());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

这个模板是一个简单的Java程序，用于发送POST请求。你需要提供请求的URL和参数，并根据需要修改代码中的变量。这个模板使用了`HttpURLConnection`类来建立连接，并发送和接收数据。在发送请求之后，它会获取响应状态码和内容，并在控制台输出。

请注意，这只是一个基础模板，你可能需要根据具体需求进行更多的定制和错误处理。

### 回答3：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

public class PostRequestTemplate {
    public static void main(String[] args) throws Exception {
        // 请求URL
        String url = "http://example.com/api";

        // 构造请求参数
        String requestData = "param1=value1&param2=value2";

        // 创建URL对象
        URL obj = new URL(url);

        // 创建HttpURLConnection对象
        HttpURLConnection connection = (HttpURLConnection) obj.openConnection();

        // 设置请求方法为POST
        connection.setRequestMethod("POST");

        // 设置请求Header
        connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");

        // 允许输入输出流
        connection.setDoOutput(true);
        connection.setDoInput(true);

        // 获取请求输出流
        OutputStream outputStream = connection.getOutputStream();
        outputStream.write(requestData.getBytes());
        outputStream.flush();
        outputStream.close();

        // 获取响应码
        int responseCode = connection.getResponseCode();

        // 读取响应内容
        BufferedReader reader;
        if (responseCode == HttpURLConnection.HTTP_OK) {
            reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
        } else {
            reader = new BufferedReader(new InputStreamReader(connection.getErrorStream()));
        }

        // 打印响应内容
        String line;
        StringBuilder response = new StringBuilder();
        while ((line = reader.readLine()) != null) {
            response.append(line);
        }
        reader.close();

        System.out.println("Response Code: " + responseCode);
        System.out.println("Response Content: " + response.toString());
    }
}

以上是一个Java发送POST请求的模板代码。通过构建URL对象和HttpURLConnection对象，设置请求方法为POST，并设置请求参数和Header。通过获取输出流将请求参数写入请求体，然后通过获取响应码和响应内容进行处理。