使用Java实现文件操作：读写、复制和删除

原创喜欢ヅ旅行 2024-09-24 14:45 137阅读 0赞

在Java中，我们可以使用`java.io.File`类进行文件操作。以下是一些基本的文件操作方法：

1. **创建文件**：
```java
File file = new File("path_to_file"); // path can be relative or absolute
if (file.exists()) { // check if the file already exists
    System.out.println("File already exists.");
} else {
    file.createNewFile(); // create a new file, if it doesn't exist yet
    System.out.println("File created successfully.");
}
```

2. **读写文件**：
```java
// Write to file
try (BufferedWriter writer = new BufferedWriter(new FileWriter(file)))) {
    writer.write("Hello, World!");
    writer.newLine(); // write a newline character
    writer.flush(); // flush the buffer to ensure the data is written immediately
}
catch (IOException e) {
    System.out.println("Error occurred while writing to file: " + e.getMessage());
}

// Read from file
try (BufferedReader reader = new BufferedReader(new FileReader(file)))) {
    String line;
    while ((line = reader.readLine()) != null) { // read until the end of file or a null value
        System.out.println(line);
    }
}
catch (IOException e) {
    System.out.println("Error occurred while reading from file: " + e.getMessage());
}
```

3. **复制文件**：
```java
// Copy file to another location using absolute path
try (FileInputStream fis = new FileInputStream(file));
     FileOutputStream fos = new FileOutputStream("path_to_destination_file")) as FileInputStream, FileOutputStream {
    byte[] buffer = new byte[1024]; // define buffer size
    int bytesRead = fis.read(buffer); // read from source file

if (bytesRead != -1) { // if data is read successfully
        fos.write(buffer, 0, bytesRead); // write to destination file
        System.out.println("File copied successfully.");
    } else {
        System.out.println("Error occurred while copying file: " + fis.readError()));
    }
}
catch (IOException e) {
    System.out.println("Error occurred while copying file: " + e.getMessage());
}
```

4. **删除文件**：
```java
// Delete file using absolute path
try {
    File fileToDelete = new File("path_to_file"); // replace with your file's path
    if (fileToDelete.exists()) { // check if the file exists
        fileToDelete.delete(); // delete the file
        System.out.println("File deleted successfully.");
    } else {
        System.out.println("Error occurred while deleting file: File doesn't exist.");
    }
} catch (IOException e) {
    System.out.println("Error occurred while deleting file: " + e.getMessage());
}
```

请确保提供正确的文件路径，否则可能会抛出`FileNotFoundException`。