Java中的异常处理机制：自定义异常、try-catch-finally示例

原创短命女 2024-12-11 16:45 2阅读 0赞

在Java中，异常处理机制帮助我们捕获和处理程序运行时可能出现的错误。以下是一个自定义异常和try-catch-finally示例：

1. 自定义异常（PersonNotExistException）：

```java
public class PersonNotExistException extends Exception {
    public PersonNotExistException(String message) {
        super(message);
    }
}
```

2. try-catch-finally结构：

```java
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

System.out.println("Enter a person's name: ");
        String nameInput = scanner.nextLine();

try {
            // Check if person exists
            if (!checkPersonExist(nameInput))) {
                throw new PersonNotExistException("Person does not exist.");
            }

System.out.println("Person found. Details: " + getPersonDetails(nameInput));
        } catch (PersonNotExistException e) {
            System.err.println(e.getMessage());
        } finally {
            scanner.close();
        }
    }

// Method to check if a person exists in the system
    private boolean checkPersonExist(String nameInput) {
        // (Insert your own method to check if a person exists)
        return true; // For demonstration purposes only
    }

// Method to fetch person details based on their name
    private String getPersonDetails(String nameInput) {
        // (Insert your own logic or database access to retrieve person details)
        return "Person details for " + nameInput + ": [Details go here]"; // For demonstration purposes only
    }
}
```

在这个示例中，我们定义了一个自定义异常`PersonNotExistException`。然后在主函数中，我们通过try-catch-finally结构来捕获可能的异常，并提供相应的处理逻辑。