Java网络编程：HTTP客户端与服务器端通信示例

原创妖狐艹你老母 2024-09-27 10:51 69阅读 0赞

在Java中，我们可以使用HttpURLConnection或者现代的HttpClient来实现HTTP客户端与服务器端的通信。下面是一些基本示例：

1. **HttpURLConnection示例**：
```java
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;

public class SimpleHttpClient {
    public static void main(String[] args) {
        String urlStr = "http://example.com/api/data";
        try {
            URL url = new URL(urlStr);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();

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

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

// 读取响应内容（如果需要的话）
            BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()))));
            String inputLine;
            StringBuilder content = new StringBuilder();

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

System.out.println("Response Content: " + content.toString());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
```

2. **HttpClient（Apache HttpClient）示例**：
在Java 8及更高版本中，你可以使用`java.net.http.HttpClient`来访问HTTP服务器。以下是一个简单的示例：

```java
import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

public class HttpClientExample {
    public static void main(String[] args) {
        // 创建HttpClient实例
        HttpClient httpClient = HttpClient.newHttpClient();

// 定义请求URI
        URI uri = URI.create("http://example.com/api/data");

// 发送GET请求
        HttpRequest request = HttpRequest.newBuilder()
                .uri(uri)
                .method(HttpMethod.GET.name())
                .build();

try (HttpResponse response = httpClient.send(request, HttpResponse.class))) {
            // 处理响应内容（如果需要的话）
            System.out.println("Response Code: " + response.statusCode());
            if (response.statusCode() == 200) {
                String content = response.body().toString();
                System.out.println("Response Content: " + content);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
```

以上示例展示了如何使用HttpURLConnection和HttpClient来实现HTTP客户端与服务器端的通信。