使用Java API发送HTTP请求示例

原创 ╰半橙微兮° 2024-11-12 06:39 1阅读 0赞

在Java中，你可以使用多种方式来发送HTTP请求。以下是使用Java标准库中的`HttpURLConnection`类来发送一个简单的GET请求的示例代码：

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

public class HttpGetRequestExample {

public static void main(String[] args) {
String urlString = "http://example.com"; //替换为你想要请求的URL try {
URL url = new URL(urlString);
 HttpURLConnection connection = (HttpURLConnection) url.openConnection();
// 设置请求方法，默认是GET connection.setRequestMethod("GET");
// 设置接受响应格式 connection.setRequestProperty("Accept", "application/json");
// 发送请求并获取响应码int responseCode = connection.getResponseCode();
 System.out.println("Response Code: " + responseCode);
//读取响应 BufferedReader in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
String inputLine;
 StringBuffer response = new StringBuffer();
 while ((inputLine = in.readLine()) != null) {
 response.append(inputLine);
 }
in.close();
//打印结果 System.out.println(response.toString());
} catch (Exception e) {
e.printStackTrace();
 }
 }
}
```这个示例展示了如何创建一个GET请求，设置请求头，并读取响应。如果你需要发送POST请求或者需要处理更复杂的HTTP特性（如HTTPS、连接池等），你可能需要使用更高级的库，比如Apache HttpClient或者Java11中引入的`HttpClient`。

以下是使用Java11的`HttpClient`发送GET请求的示例：

```javaimport 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) {
String urlString = "http://example.com"; //替换为你想要请求的URL HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
.uri(URI.create(urlString))
.header("Accept", "application/json")
.build();

try {
 HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
 System.out.println("Response Code: " + response.statusCode());
 System.out.println("Response Body: " + response.body());
} catch (Exception e) {
e.printStackTrace();
 }
 }
}
```这个示例使用了Java11中引入的`HttpClient`，它提供了一个更现代和更强大的API来处理HTTP请求。记得在实际使用时替换`urlString`为你想要请求的实际URL。