Java IO操作：文件读写问题实例分析-蒲公英云

Java IO操作：文件读写问题实例分析

在Java编程中，IO（Input/Output）操作主要涉及文件的读取、写入以及文件的各种属性管理。以下是一些具体问题实例和分析：

文件读写：
```java
import java.io.File;
import java.io.IOException;

public class FileReadWrite {
public static void main(String[] args) {
// 读文件
try {
File file = new File(“example.txt”);
String content = readFile(file);
System.out.println(content);
} catch (IOException e) {
e.printStackTrace();
}

    // 写文件
    try {
        String newContent = "Updated content!";
        writeToFile(newContent, "updated_example.txt"));
        System.out.println("File updated successfully.");
    } catch (IOException i) {
        i.printStackTrace();
        System.out.println("Error occurred while updating file.");
    }
}
// 读文件
private static String readFile(File file) throws IOException {
    StringBuilder content = new StringBuilder();
    try (BufferedReader br = new BufferedReader(new FileReader(file)))) {
        String line;
        while ((line = br.readLine()) != null)) {
            content.append(line).append("\n");
        }
    }
    return content.toString().trim(); // 去除末尾的空格
}
// 写文件
private static void writeToFile(String content, String fileName) throws IOException {
    File file = new File(fileName);
    try (PrintWriter writer = new PrintWriter(file)) {
        writer.write(content);
        writer.flush(); // 确保内容立即写入磁盘
    }
}

}

2. 文件属性管理：
```java
import java.io.File;
import java.io.IOException;
public class FileAttributeManagement {
    public static void main(String[] args) throws IOException {
        // 获取文件属性
        File file = new File("example.txt");
        String fileName = file.getName();
        long fileSize = file.length(); // 文件大小
        System.out.println("File Name: " + fileName);
        System.out.println("File Size (in bytes): " + fileSize);
        // 修改文件属性
        if (file.exists() && !file.isDirectory())) {
            file.setLength(1024); // 设置文件大小为1KB
            System.out.println("File size modified successfully to 1 KB.");
        } else {
            System.out.println("Error: File does not exist or is a directory.");
        }
    }
}