API调用失败：Java处理REST API异常的实例

原创叁歲伎倆 2024-11-29 01:45 73阅读 0赞

在Java中，处理REST API异常通常会涉及HttpURLConnection或者更现代的RestTemplate。以下是一个处理API调用失败的例子：

1. 使用`HttpURLConnection`:

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

public class RestApiExceptionHandler {
    public static void main(String[] args) {
        try {
            String apiUrl = "http://api.example.com/data";
            HttpURLConnection connection = (HttpURLConnection) new URL(apiUrl).openConnection();
            connection.setRequestMethod("GET");
            int responseCode = connection.getResponseCode();
            if (responseCode == 200) { // Success
                BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream())));
                String line;
                StringBuilder apiResponse = new StringBuilder();
                while ((line = reader.readLine()) != null) {
                    apiResponse.append(line).append("\n");
                }
                System.out.println("API Response: " + apiResponse.toString());
            } else {
                System.out.println("API Call Failed. Response Code: " + responseCode);
            }
        } catch (Exception e) {
            // Log the error or display to user
            System.err.println("Error occurred while handling API call failure: " + e.getMessage());
        }
    }
}
```

2. 使用`RestTemplate`:

```java
import org.springframework.http.HttpMethod;
import org.springframework.http.ResponseEntity;
import org.springframework.web.client.RestTemplate;

public class RestApiExceptionHandlerSpring {
    public static void main(String[] args) {
        try {
            String apiUrl = "http://api.example.com/data";
            ResponseEntity<String> response = restTemplate.exchange(apiUrl, HttpMethod.GET));
            if (response.getStatusCode() == 200) { // Success
                System.out.println("API Response: " + response.getBody()));
            } else {
                System.out.println("API Call Failed. Response Code: " + response.getStatusCode()));
            }
        } catch (Exception e) {
            // Log the error or display to user
            System.err.println("Error occurred while handling API call failure: " + e.getMessage());
        }
    }
}
```

无论使用哪种方式，关键是要对API调用的结果进行适当的处理，并在出现错误时提供有用的反馈。