Java文件操作基础：读写文件的内容示例

原创逃离我推掉我的手 2024-10-07 03:15 64阅读 0赞

在Java中，我们可以使用`FileInputStream`和`FileOutputStream`来读写文件内容。以下是一些基本的示例：

1. **读取文件**：
```java
import java.io.File;
import java.io.FileInputStream;

public class ReadFile {
    public static void main(String[] args) {
        File file = new File("path_to_your_file.txt"); // replace with your file path

if (file.exists()) { // check if file exists
            FileInputStream fis = new FileInputStream(file);
            try {
                byte[] content = new byte[(int)file.length()]; // read entire file into a byte array
                fis.read(content); // read from the fis and store in content array

// Display the content of the file
                for (byte b : content) {
                    System.out.print((char)b) + " ";
                }
            } finally {
                if (fis != null) {
                    fis.close();
                }
            }
        } else {
            System.out.println("File does not exist.");
        }
    }
}
```

2. **写入文件**：
```java
import java.io.File;
import java.io.FileWriter;

public class WriteToFile {
    public static void main(String[] args) {
        File file = new File("path_to_your_file.txt"); // replace with your file path

if (!file.exists()) { // check if file doesn't exist already
            try (FileWriter writer = new FileWriter(file)) { // create a FileWriter to write into the file
                writer.write("This is content written to the file."); // write some sample content
            } catch (IOException e) {
                System.out.println("Error writing to file: " + e.getMessage());
            }
        } else {
            System.out.println("File already exists.");
        }
    }
}
```

这些示例展示了如何在Java中读取和写入文件内容。请根据你的实际需求替换路径。