通过Java实现HTTP请求与响应的基本步骤实例

原创逃离我推掉我的手 2024-10-12 13:48 27阅读 0赞

在Java中，我们可以使用java.net包中的类来发送HTTP请求和接收响应。以下是一个基本的步骤实例：

1. 导入所需的类：
```java
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
```

2. 创建一个方法来发送GET请求：
```java
public String sendGetRequest(String url) throws Exception {
    HttpURLConnection connection = (HttpURLConnection) new URL(url).openConnection();
    connection.setRequestMethod("GET");
    
    int responseCode = connection.getResponseCode();
    if (responseCode == 200) { // Success
        BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream()))));
        StringBuilder responseContent = new StringBuilder();
        String line;
        while ((line = br.readLine()) != null) {
            responseContent.append(line);
        }
        br.close();
        
        return responseContent.toString(); // Return the content
    } else { // Error or not a GET request
        throw new Exception("Error occurred during HTTP GET request. Response Code: " + responseCode);
    }
}
```

3. 使用这个方法来发送GET请求并获取响应内容：
```java
public void sendGetRequestAndPrintResponse(String url) throws Exception {
    String response = sendGetRequest(url);
    
    if (response != null && !response.isEmpty()) { // Response received and not empty
        System.out.println("Received Response from URL: " + url);
        System.out.println("Response Content: " + response);
    } else { // No response or response is empty
        System.out.println("No Response Received from URL: " + url);
    }
}
```

4. 调用`sendGetRequestAndPrintResponse(url)`方法，替换`url`为你想要请求的URL。

以上就是使用Java实现HTTP请求与响应的基本步骤实例。