如何使用Java进行文件操作，比如读写、复制等？

原创旧城等待， 2025-03-21 00:39 6阅读 0赞

在Java中，我们可以使用`java.io`包中的类来进行文件的操作。以下是一些基本的文件操作：

1. **读取文件**：
```java
import java.io.BufferedReader;
import java.io.FileReader;

String filename = "path_to_your_file.txt"; // replace with your file path

try (BufferedReader br = new BufferedReader(new FileReader(filename)))) {
    String line;
    while ((line = br.readLine()) != null) {
        System.out.println(line);
    }
}
catch (Exception e) {
    e.printStackTrace();
}
```

2. **写入文件**：
```java
String content = "Your content here"; // replace with your content

import java.io.FileWriter;
import java.io.IOException;

try (FileWriter writer = new FileWriter("path_to_your_file.txt"));) {
    writer.write(content);
} catch (IOException e) {
    e.printStackTrace();
}
```

3. **复制文件**：
```java
String sourcePath = "path_to_source_file.txt"; // replace with your source file path
String destinationPath = "path_to_destination_directory/your_file_name.txt"; // replace with your destination directory and file name

import java.io.File;
import java.io.IOException;

try {
    File sourceFile = new File(sourcePath);
    if (sourceFile.exists()) { // check if the source file exists

File destinationDirectory = new File(destinationPath.substring(0, destinationPath.length() - 17))); // extract the directory part from the destination path
        if (!destinationDirectory.mkdirs()) { // create the directory if it doesn't exist
            System.out.println("Failed to create destination directory.");
            return;
        }

String fileName = sourceFile.getName(); // get the file name
        File destinationFile = new File(destinationPath + "/" + fileName)); // build the full path of the destination file

if (destinationFile.exists()) { // check if the destination file already exists
            System.out.println("Destination file already exists. Skipping.");
            return;
        }

try (FileInputStream fis = new FileInputStream(sourceFile); FileOutputStream fos = new FileOutputStream(destinationFile))) {
            byte[] buffer = new byte[1024]; // create a buffer of size 1KB
            int bytesRead;
            while ((bytesRead = fis.read(buffer))) != -1) { // read from the source file and write to the destination file
                fos.write(buffer, 0, bytesRead);
            }
        } catch (IOException e) {
            System.out.println("An error occurred while copying the file: " + e.getMessage());
            e.printStackTrace();
        }
    } else { // check if the source file exists
        System.out.println("Source file doesn't exist. Skipping.");
        return;
    }
} catch (IOException e) {
    System.out.println("An error occurred while copying the file: " + e.getMessage());
    e.printStackTrace();
}
```

以上就是使用Java进行文件操作的一些基本示例。根据实际需求，你可能需要处理更复杂的文件操作，例如移动文件、删除文件等。