Java文件操作异常处理：IOException示例

原创桃扇骨 2024-11-28 22:30 49阅读 0赞

在Java中，`IOException`是一个基类，用于表示在读写数据到流时发生的任何错误。下面是一些关于如何捕获和处理`IOException`的示例：

1. **文件不存在**：
```java
import java.io.File;
import java.io.IOException;

public class FileNotFoundExample {
    public static void main(String[] args) {
        String filePath = "non_existent_file.txt";

// Try to read file, which will throw IOException if file doesn't exist
        try (File file = new File(filePath)) {
            System.out.println("File exists: " + file.exists());
        } catch (IOException e) {
            System.err.println("Error reading file: " + e.getMessage());
            e.printStackTrace(); // Print stack trace for better debugging
        }
    }
}
```
2. **文件读写**：
```java
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;

public class FileReadWriteExample {
    public static void main(String[] args) {
        String filePath = "input.txt";

// Try to read file and write it back, which will throw IOException if file doesn't exist or cannot be read/written
        try (BufferedReader br = new BufferedReader(new FileReader(filePath)))) {
            StringBuilder sb = new StringBuilder();
            String line;

while ((line = br.readLine()) != null) {
                sb.append(line).append("\n");
            }

// Write back the processed file
            try (FileWriter fw = new FileWriter(filePath)) {
                fw.write(sb.toString());
            }
        } catch (IOException e) {
            System.err.println("Error reading/writing file: " + e.getMessage());
            e.printStackTrace(); // Print stack trace for better debugging
        }
    }
}
```
在上述示例中，我们首先检查文件是否存在。如果不存在，`File`构造函数会抛出`FileNotFoundException`。然后，我们在读写文件时处理可能的`IOException`。

注意：在实际开发中，应尽量使用异常处理器或编程模式来捕获和处理这些异常，而不是简单地打印堆栈跟踪。