网络编程问题：Java如何进行HTTP请求和响应

原创 Myth丶恋晨 2024-10-15 22:42 75阅读 0赞

在Java中，你可以使用多种库来实现HTTP请求和响应。以下是两种常用的库：`java.net.HttpURLConnection` 和 `java.util.concurrent Executors` 进行的简单示例：

1. 使用HttpURLConnection:

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

public class HttpExample {
    public static void main(String[] args) throws Exception {
        // 创建URL对象
        URL url = new URL("http://www.example.com");

// 打开连接
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();

// 设置请求方法（GET或POST等）
        connection.setRequestMethod("GET");

// 获取响应状态码，如200表示成功
        int responseCode = connection.getResponseCode();
        System.out.println("Response Code: " + responseCode);

// 读取响应内容
        BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()))));
        String inputLine;
        StringBuffer content = new StringBuffer();

while ((inputLine = br.readLine()) != null)) {
            content.append(inputLine);
        }

br.close();
        System.out.println("Response Content: " + content.toString());
    }
}
```

2. 使用Executors并配合第三方库（如OkHttp、HttpURLConnection-Java7等）：

```java
import java.io.IOException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class HttpExampleUsingExecutor {
    public static void main(String[] args) throws IOException {
        ExecutorService executor = Executors.newSingleThreadExecutor();

// 使用OkHttp或者其他HTTP客户端发送请求
        // 这里以OkHttp为例，其他库实现方式类似
        OkHttpHttpClient httpClient = new OkHttpHttpClient();
        httpClient.execute("http://www.example.com", null, new OkHttpCallback() {
            @Override
            public void onFailure(Call call, IOException e) {
                executor.shutdown(); // 关闭线程池
                System.out.println("Error: " + e.getMessage());
            }

@Override
            public void onResponse(Call call, Response response) throws IOException {
                if (response.isSuccessful()) {
                    String content = response.body().string();
                    System.out.println("Response Content: " + content);
                } else {
                    System.out.println("Unexpected code " + response.code() + ": " + response.message());
                }
            }
        }));

// 等待线程池关闭
        executor.shutdown();
        while (!executor.isTerminated())) {
            Thread.sleep(100); // 暂停一秒，模拟耗时操作
        }

System.out.println("Executor Service is terminated.");
    }
}
```

注意：在实际项目中，推荐使用OkHttp、 Retrofit 或者 HttpURLConnection-Java7等成熟的HTTP客户端库。