在Java應用程序中，處理異常的主要方法是使用try-catch語句

1. 使用try-catch語句捕獲異常：

public class ExceptionHandlingExample {
    public static void main(String[] args) {
        try {
            // 可能會拋出異常的代碼
            int result = riskyOperation();
            System.out.println("Result: " + result);
        } catch (Exception e) {
            // 處理異常的代碼
            System.err.println("An exception occurred: " + e.getMessage());
        }
    }

    private static int riskyOperation() throws ArithmeticException {
        int a = 10;
        int b = 0;
        return a / b; // 這將導致ArithmeticException（除以零）
    }
}

2. 使用finally塊確保資源被正確關閉：

public class ExceptionHandlingWithFinally {
    public static void main(String[] args) {
        FileInputStream fis = null;
        try {
            fis = new FileInputStream("example.txt");
            // 讀取和處理文件內容的代碼
        } catch (IOException e) {
            System.err.println("An I/O exception occurred: " + e.getMessage());
        } finally {
            if (fis != null) {
                try {
                    fis.close(); // 確保文件輸入流被正確關閉
                } catch (IOException e) {
                    System.err.println("Failed to close the file input stream: " + e.getMessage());
                }
            }
        }
    }
}

3. 使用自定義異常類處理特定錯誤：

public class CustomExceptionExample {
    public static void main(String[] args) {
        try {
            validateInput("invalid_input");
        } catch (InvalidInputException e) {
            System.err.println("Invalid input: " + e.getMessage());
        }
    }

    private static void validateInput(String input) throws InvalidInputException {
        if (input == null || input.isEmpty()) {
            throw new InvalidInputException("Input cannot be null or empty");
        }
        // 其他驗證邏輯
    }

    static class InvalidInputException extends Exception {
        public InvalidInputException(String message) {
            super(message);
        }
    }
}

4. 使用多個catch塊處理不同類型的異常：

public class MultipleCatchBlocks {
    public static void main(String[] args) {
        try {
            performDifferentOperations();
        } catch (ArithmeticException e) {
            System.err.println("An arithmetic exception occurred: " + e.getMessage());
        } catch (ArrayIndexOutOfBoundsException e) {
            System.err.println("An array index out of bounds exception occurred: " + e.getMessage());
        } catch (Exception e) {
            System.err.println("An unexpected exception occurred: " + e.getMessage());
        }
    }

    private static void performDifferentOperations() {
        // 可能會拋出不同類型異常的代碼
    }
}

5. 使用異常鏈傳遞異常信息：

public class ExceptionChaining {
    public static void main(String[] args) {
        try {
            processData();
        } catch (DataProcessingException e) {
            System.err.println("Data processing failed: " + e.getMessage());
            e.printStackTrace();
        }
    }

    private static void processData() throws DataProcessingException {
        try {
            readData();
        } catch (IOException e) {
            throw new DataProcessingException("Failed to read data", e);
        }
    }

    private static void readData() throws IOException {
        // 讀取數據的代碼，可能會拋出IOException
    }

    static class DataProcessingException extends Exception {
        public DataProcessingException(String message, Throwable cause) {
            super(message, cause);
        }
    }
}

通過使用這些方法，你可以更有效地處理Java應用程序中的異常。