使用Java进行HTTP请求和响应：GET、POST案例解析

原创喜欢ヅ旅行 2024-12-03 08:48 8阅读 0赞

在Java中，我们可以使用各种库来进行HTTP请求。这里我们主要看两个常用的库：HttpURLConnection和Apache HttpClient。

1. HttpURLConnection (基础版本)

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

public class HttpGetExample {
    public static void main(String[] args) throws Exception {
        String urlStr = "http://example.com"; // 替换为实际URL

URL url = new URL(urlStr);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();

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

// 获取响应状态码，判断请求是否成功
        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 outputLine;
        StringBuilder contentBuilder = new StringBuilder();

while ((outputLine = br.readLine()) != null)) {
            contentBuilder.append(outputLine);
        }

br.close();
        connection.disconnect();

System.out.println("Response Content: " + contentBuilder.toString());
    }
}
```

2. Apache HttpClient (更强大且易于管理)

```java
import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.util.EntityUtils;

public class HttpGetExampleHttpClient {
    public static void main(String[] args) throws Exception {
        // 创建CloseableHttpClient实例
        CloseableHttpClient httpClient = HttpClients.createDefault();

try {
            // 使用HttpGet方法发送GET请求
            HttpGet httpGet = new HttpGet("http://example.com"); // 替换为实际URL
            CloseableHttpResponse response = httpClient.execute(httpGet);

// 检查响应状态码是否成功
            if (response.getStatusLine().getStatusCode() == 200) {
                HttpEntity entity = response.getEntity();
                if (entity != null) {
                    System.out.println("Response Content: " + EntityUtils.toString(entity)));
                }
            }

// 关闭响应和客户端连接
            response.close();
            httpClient.close();

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

以上就是使用Java进行HTTP GET请求和响应的两个示例。根据实际需求，可以选择不同的库来进行操作。