文件与路径操作

1import java.nio.file.Path;
2
3public class AbsolutePathExample {
4    public static void main(String[] args) {
5        Path relative = Path.of("config.xml");
6        
7        // 转换为绝对路径
8        Path absolute = relative.toAbsolutePath();
9        
10        System.out.println("相对路径: " + relative);
11        System.out.println("绝对路径: " + absolute);
12    }
13}

1import java.nio.file.Path;
2
3public class PathOperations {
4    public static void main(String[] args) {
5        Path baseDir = Path.of("/home/user/project");
6        Path subDir = Path.of("src/main");
7
8        // 1. Resolve：连接路径
9        Path fullPath = baseDir.resolve(subDir);
10        System.out.println("已解析: " + fullPath);
11
12        // 2. Normalize：移除冗余的 ".."
13        Path messyPath = Path.of("/home/user/project/./build/../src");
14        System.out.println("已规范化: " + messyPath.normalize());
15
16        // 3. Relativize：如何从 A 到 B？
17        Path pathA = Path.of("/home/user/docs");
18        Path pathB = Path.of("/home/user/music/song.mp3");
19        Path pathAtoB = pathA.relativize(pathB);
20        
21        System.out.println("从文档目录到音乐目录: " + pathAtoB);
22    }
23}

1import java.nio.file.Files;
2import java.nio.file.Path;
3import java.io.IOException;
4
5public class MetadataExample {
6    public static void main(String[] args) throws IOException {
7        // 假设我们在此位置有一个文件
8        Path target = Path.of("build.gradle");
9
10        // 检查是否存在而不抛出异常
11        if (Files.exists(target)) {
12            System.out.println("存在: 是");
13            System.out.println("可读: " + Files.isReadable(target));
14            System.out.println("可写: " + Files.isWritable(target));
15            
16            // 这些操作在文件访问失败时可能会抛出 IOException
17            System.out.println("大小: " + Files.size(target) + " 字节");
18            System.out.println("最后修改时间: " + Files.getLastModifiedTime(target));
19        } else {
20            System.out.println("文件不存在。");
21        }
22    }
23}

1import java.io.File;
2import java.nio.file.Path;
3
4public class InteropExample {
5    public static void main(String[] args) {
6        File legacyFile = new File("legacy.txt");
7        
8        // 将 File 转换为 Path
9        Path modernPath = legacyFile.toPath();
10        System.out.println("转换为 Path: " + modernPath);
11        
12        // 将 Path 转换为 File
13        File backToFile = modernPath.toFile();
14        System.out.println("转换回 File: " + backToFile);
15    }
16}