使用Java进行HTTP请求与响应

原创以你之姓@ 2024-09-17 15:45 137阅读 0赞

在Java中，我们可以使用各种库来发送HTTP请求和处理响应。以下是两个常用的库：`java.net.URLConnection` 和 `java.util.concurrent Executors`。

1. 使用URLConnection：

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

public class Main {
    public static void main(String[] args) {
        // 创建URL对象
        URL url = new URL("https://example.com/api");

try (HttpURLConnection connection = (HttpURLConnection) url.openConnection()) {

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

// 获取响应码
            int responseCode = connection.getResponseCode();
            System.out.println("Response Code: " + responseCode);

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

String line;
                StringBuilder responseContent = new StringBuilder();

while ((line = reader.readLine()) != null) {
                    responseContent.append(line);
                }

reader.close();
                System.out.println("Response Content: " + responseContent.toString());

} else {
                System.out.println("Error occurred. Response Code: " + responseCode);
            }

} catch (Exception e) {
            e.printStackTrace();
        }
    }
}
```

2. 使用Executors：

使用Java的`java.util.concurrent Executors`工具类可以创建线程来执行HTTP请求。以下是一个简单的例子：

```java
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class Main {
    public static void main(String[] args) {
        // 创建URL对象
        URL url = new URL("https://example.com/api");

ExecutorService executor = Executors.newSingleThreadExecutor();
        
        try (HttpURLConnection connection = (HttpURLConnection) url.openConnection()); {

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

// 获取响应码
            int responseCode = connection.getResponseCode();
            System.out.println("Response Code: " + responseCode);

if (responseCode == HttpURLConnection.HTTP_OK) {
                // 使用线程处理读取内容的操作
                executor.execute(() -> {
                    BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()))));

String line;
                    StringBuilder responseContent = new StringBuilder();

while ((line = reader.readLine()) != null) {
                        responseContent.append(line);
                    }

reader.close();
                    System.out.println("Response Content: " + responseContent.toString());
                }));
            } else {
                System.out.println("Error occurred. Response Code: " + responseCode);
            }

} catch (Exception e) {
            e.printStackTrace();
        }
        // 关闭线程池
        executor.shutdown();
    }
}
```

这两个示例都使用了Java的`HttpURLConnection`来发送HTTP请求。通过创建一个线程，可以异步地处理响应内容。