Java Files和Paths的使用demo详解

import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.io.IOException;

public class CreateFileAndDirectory {
    public static void main(String[] args) throws IOException {
    	//文件
        Path pathToFile = Paths.get("example.txt");
        //目录
        Path pathToDir = Paths.get("exampleDir");
		//多级目录
		Path pathDirectories = Paths.get("java\exampleDir\pathDirectories\dir");

        // 创建文件
        try {
        	Files.createFile(pathToFile);
         } catch (IOException e) {
           throw new RuntimeException(e);
        }

        // 创建目录
        try {
        	Files.createDirectory(pathToDir);
		} catch (IOException e) {
             throw new RuntimeException(e);
        }

		//创建多级目录
         try {
             Files.createDirectories(pathDirectories);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }
}

import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.io.IOException;
import java.util.Arrays;

public class WriteToFile {
    public static void main(String[] args) throws IOException {
        Path path = Paths.get("example.txt");

        // 写入字节数组
        byte[] bytes = "Hello, world!".getBytes();
        try {
			Files.write(path, bytes);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        

        // 写入字符串
        String text = "Hello, world!";
        try {
			Files.write(path, text.getBytes());
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
        

        // 写入字符串列表
        Iterable<String> lines = Arrays.asList("line 1", "line 2", "line 3");
           try {
			Files.write(path, lines);
        } catch (IOException e) {
            throw new RuntimeException(e);
        } 
    }
}

import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.io.IOException;
import java.util.List;

public class ReadFromFile {
    public static void main(String[] args) throws IOException {
        Path path = Paths.get("example.txt");

        // 读取字节数组
        byte[] bytes = Files.readAllBytes(path);
        System.out.println(new String(bytes));

        // 读取字符串列表
        List<String> lines = Files.readAllLines(path);

        // 使用BufferedReader读取文件
        BufferedReader reader = Files.newBufferedReader(path);
        String line = null;
        while ((line = reader.readLine()) != null

// 删除一个文件
Path fileToDeletePath = Paths.get("fileToDelete.txt");
try {
    Files.delete(fileToDeletePath);
    System.out.println("文件删除成功");
} catch (IOException e) {
    System.out.println("文件删除失败");
}

// 删除一个目录
Path dirToDeletePath = Paths.get("dirToDelete");
try {
    Files.delete(dirToDeletePath);
    System.out.println("目录删除成功");
} catch (IOException e) {
    System.out.println("目录删除失败");
}


//如果文件存在才删除，不会抛出异常
 try {
 		//返回布尔值
       Files.deleteIfExists("dirToDelete/dir");
   } catch (IOException e) {
       throw new RuntimeException(e);
   }

// 复制一个文件
//资源地址
Path sourceFilePath = Paths.get("sourceFile.txt");
//目标地址
Path targetFilePath = Paths.get("targetFile.txt");


try {
    Files.copy(sourceFilePath, targetFilePath,StandardCopyOption.REPLACE_EXISTING);
    System.out.println("文件复制成功");
} catch (IOException e) {
    System.out.println("文件复制失败：" + e.getMessage());
}

// 复制一个目录
Path sourceDirPath = Paths.get("C:/Users/username/Desktop/sourceDir");
Path targetDirPath = Paths.get("C:/Users/username/Desktop/targetDir");
try {
//CopyFileVisitor是需要自己实现的

    Files.walkFileTree(sourceDirPath, new CopyFileVisitor(sourceDirPath, targetDirPath));
    System.out.println("目录复制成功");
} catch (IOException e) {
    System.out.println("目录复制失败：" + e.getMessage());
}

import java.io.IOException;
import java.nio.file.*;
import java.nio.file.attribute.BasicFileAttributes;

public class CopyFileVisitor extends SimpleFileVisitor<Path> {
    private final Path sourceDir;
    private final Path targetDir;

    public CopyFileVisitor(Path sourceDir, Path targetDir) {
        this.sourceDir = sourceDir;
        this.targetDir = targetDir;
    }

    @Override
    public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {
        Path targetPath = targetDir.resolve(sourceDir.relativize(dir));
        try {
            Files.copy(dir, targetPath);
        } catch (FileAlreadyExistsException e) {
            if (!Files.isDirectory(targetPath)) {
                throw e;
            }
        }
        return FileVisitResult.CONTINUE;
    }

    @Override
    public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
        Path targetPath = targetDir.resolve(sourceDir.relativize(file));
        Files.copy(file, targetPath, StandardCopyOption.REPLACE_EXISTING);
        return FileVisitResult.CONTINUE;
    }
}

    try {
    //这个操作可以做移动或重命名
       Files.move(Paths.get("source.txt"),Paths.get("target.txt"), StandardCopyOption.REPLACE_EXISTING);
      } catch (IOException e) {
           throw new RuntimeException(e);
       }

 Path start = Paths.get("sourceDir");
        int maxDepth = Integer.MAX_VALUE;

        try {
            Files.walk(start, maxDepth).forEach(System.out::println);
        } catch (IOException e) {
            throw new RuntimeException(e);
        }

 try {

            Path path = Paths.get("F:\\java\\2.txt").toAbsolutePath();
            System.out.println("文件是否存在: " + Files.exists(path));
            System.out.println("是否是目录: " + Files.isDirectory(path));
            System.out.println("是否是可执行文件: " + Files.isExecutable(path));
            System.out.println("是否可读: " + Files.isReadable(path));
            System.out.println("判断是否是一个文件: " + Files.isRegularFile(path));
            System.out.println("是否可写: " + Files.isWritable(path));
            System.out.println("文件是否不存在: " + Files.notExists(path));
            System.out.println("文件是否隐藏: " + Files.isHidden(path));

            System.out.println("文件大小: " + Files.size(path));
            System.out.println("文件存储在SSD还是HDD: " + Files.getFileStore(path));
            System.out.println("文件修改时间：" + Files.getLastModifiedTime(path));
            System.out.println("文件拥有者： " + Files.getOwner(path));
            System.out.println("文件类型: " + Files.probeContentType(path));
        } catch (IOException e) {
            throw new RuntimeException(e);
        }