Java 文件 - Java.nio.file.Files 类

1Path path1 = Paths.get("/tmp/file.txt"); // For UNIX
2
3Path path2 = Paths.get("D:/data/file.txt"); // For Windows

1Path path1 = Paths.get("/tmp", "file.txt");
2
3Path path2 = Paths.get("D:", "data", "file.txt");
4
5Path path3 = Paths.get("D:/data", "file.txt") ;

 1package com.journaldev.examples;
 2
 3import java.io.IOException;
 4import java.nio.file.Files;
 5import java.nio.file.Path;
 6import java.nio.file.Paths;
 7
 8/**
 9 * Java Create file using Files class
10 * 
11 * @author pankaj
12 *
13 */
14public class FilesCreateFileExample {
15
16    public static void main(String[] args) {
17    	
18    	//initialize Path object
19    	Path path = Paths.get("D:/data/file.txt");
20    	//create file
21    	try {
22    		Path createdFilePath = Files.createFile(path);
23    		System.out.println("File Created at Path : "+createdFilePath);
24    	} catch (IOException e) {
25    		e.printStackTrace();
26    	}
27    }
28}

1File Created at Path : D:\data\file.txt

 1package com.journaldev.examples;
 2
 3import java.nio.file.Files;
 4import java.nio.file.Path;
 5import java.nio.file.Paths;
 6
 7/**
 8 * Java Create directories using Files class
 9 * 
10 * @author pankaj
11 *
12 */
13public class FilesCreateDirectoriesExample {
14
15    public static void main(String[] args) {
16    	// initialize Path objects
17    	Path path1 = Paths.get("D:/pankaj");
18    	Path path2 = Paths.get("D:/pankaj/java7");
19    	Path path3 = Paths.get("D:/pankaj/java7/Files");
20    	
21    	try {
22    		Path createdDir1 = Files.createDirectory(path1);//first level directory
23    		Path createdDir2 = Files.createDirectory(path2);//second level directory
24    		Path createdDir3 = Files.createDirectory(path3);//all level directories
25    		System.out.println("First Level Directory Created at Path : "+createdDir1);
26    		System.out.println("Second Level Directory Created at Path : "+createdDir2);
27    		System.out.println("All Level Directories Created at Path : "+createdDir3);
28    	} catch (Exception e) {
29    		e.printStackTrace();
30    	}
31    }
32}

1First Level Directory Created at Path : D:\pankaj
2Second Level Directory Created at Path : D:\pankaj\java7
3All Level Directories Created at Path : D:\pankaj\java7\Files

1File file = new File(“D:/data/file.txt”);
2
3Path path = file.toPath();
4
5File file1 = path.toFile();

 1package com.journaldev.examples;
 2
 3import java.nio.file.Files;
 4import java.nio.file.Path;
 5import java.nio.file.Paths;
 6import java.util.List;
 7
 8/**
 9 * Java Files read file example
10 * 
11 * @author pankaj
12 *
13 */
14public class FilesReadFileExample {
15
16    public static void main(String[] args) {
17    	
18    	Path path = Paths.get("D:/data/file.txt");
19    	try {
20    		byte[] bs = Files.readAllBytes(path);
21    		List<String> strings = Files.readAllLines(path);
22    		
23    		System.out.println("Read bytes: \n"+new String(bs));
24    		System.out.println("Read lines: \n"+strings);
25    	} catch (Exception e) {
26    		e.printStackTrace();
27    	}
28    }
29
30}

1Read bytes: 
2Hello world
3This is Read file example
4Thank you
5Read lines: 
6[Hello world, This is Read file example, Thank you]

 1package com.journaldev.examples;
 2
 3import java.nio.file.Files;
 4import java.nio.file.Path;
 5import java.nio.file.Paths;
 6import java.nio.file.StandardCopyOption;
 7
 8/**
 9 * Java Files copy file example
10 * 
11 * @author pankaj
12 *
13 */
14public class FilesCopyFileExample {
15
16    public static void main(String[] args) {
17    	Path sourcePath = Paths.get("D:/data/sourceFile.txt");
18    	Path targetPath = Paths.get("D:/data/targetFile.txt");
19    	
20    	try {
21    		Path path = Files.copy(sourcePath, targetPath,StandardCopyOption.REPLACE_EXISTING);//copy with REPLACE_EXISTING option
22    		System.out.println("Target file Path : "+path);
23    		System.out.println("Copied Content : \n"+new String(Files.readAllBytes(path)));
24    	} catch (Exception e) {
25    		e.printStackTrace();
26    	}
27
28    }
29
30}

1Target file Path : D:\data\targetFile.txt
2Copied Content : 
3Hello world
4This is Copy file example
5Thank you

 1package com.journaldev.examples;
 2
 3import java.nio.file.Files;
 4import java.nio.file.Path;
 5import java.nio.file.Paths;
 6import java.nio.file.StandardCopyOption;
 7
 8/**
 9 * Java Files move file example
10 * 
11 * @author pankaj
12 *
13 */
14public class FilesMoveFileExample {
15
16    public static void main(String[] args) {
17    	Path sourcePath = Paths.get("D:/data/sourceFile.txt");
18    	Path targetPath = Paths.get("D:/data/targetFile.txt");
19    	try {
20    		Path path = Files.move(sourcePath, targetPath,StandardCopyOption.REPLACE_EXISTING);//move with REPLACE_EXISTING option
21    		System.out.println("Target file Path : "+path);
22    		System.out.println("Moved Content : \n"+new String(Files.readAllBytes(path)));
23    	} catch (Exception e) {
24    		e.printStackTrace();
25    	}
26    }
27
28}

 1package com.journaldev.examples;
 2
 3import java.nio.file.Files;
 4import java.nio.file.Path;
 5import java.nio.file.Paths;
 6
 7/**
 8 * Java Files write file example
 9 * 
10 * @author pankaj
11 *
12 */
13public class FilesWriteFileExample {
14
15    public static void main(String[] args) {
16    	Path path = Paths.get("D:/data/test.txt");
17    	try {
18    		String str = "This is write file Example";
19    		byte[] bs = str.getBytes();
20    		Path writtenFilePath = Files.write(path, bs);
21    		System.out.println("Written content in file:\n"+ new String(Files.readAllBytes(writtenFilePath)));
22    	} catch (Exception e) {
23    		e.printStackTrace();
24    	}
25
26    }
27
28}

 1package com.journaldev.examples;
 2
 3import java.io.IOException;
 4import java.nio.file.FileVisitResult;
 5import java.nio.file.FileVisitor;
 6import java.nio.file.Files;
 7import java.nio.file.Path;
 8import java.nio.file.Paths;
 9import java.nio.file.attribute.BasicFileAttributes;
10
11/**
12 * Java Files walk file tree example
13 * 
14 * @author pankaj
15 *
16 */
17public class FilesWalkFileTreeExample {
18
19    public static void main(String[] args) {
20    	Path path = Paths.get("D:/pankaj");
21    	try {
22    		Files.walkFileTree(path, new FileVisitor<Path>() {
23
24    			@Override
25    			public FileVisitResult postVisitDirectory(Path dir, IOException exc) throws IOException {
26    				System.out.println("Post Visit Directory: "+dir);
27    				return FileVisitResult.CONTINUE;
28    			}
29
30    			@Override
31    			public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) throws IOException {
32    				System.out.println("Pre Visit Directory: "+dir);
33    				return FileVisitResult.CONTINUE;
34    			}
35
36    			@Override
37    			public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
38    				System.out.println("Visit File: "+file);
39    				return FileVisitResult.CONTINUE;
40    			}
41
42    			@Override
43    			public FileVisitResult visitFileFailed(Path file, IOException exc) throws IOException {
44    				System.out.println("Visit Failed File: "+file);
45    				return FileVisitResult.CONTINUE;
46    			}
47    		});
48    	} catch (Exception e) {
49    		e.printStackTrace();
50    	}
51
52    }
53
54}

 1Pre Visit Directory: D:\pankaj
 2Pre Visit Directory: D:\pankaj\java6
 3Pre Visit Directory: D:\pankaj\java6\Files
 4Visit File: D:\pankaj\java6\Files\file.txt.txt
 5Post Visit Directory: D:\pankaj\java6\Files
 6Post Visit Directory: D:\pankaj\java6
 7Pre Visit Directory: D:\pankaj\java7
 8Pre Visit Directory: D:\pankaj\java7\Files
 9Visit File: D:\pankaj\java7\Files\file.txt.txt
10Post Visit Directory: D:\pankaj\java7\Files
11Post Visit Directory: D:\pankaj\java7
12Pre Visit Directory: D:\pankaj\java8
13Pre Visit Directory: D:\pankaj\java8\Files
14Visit File: D:\pankaj\java8\Files\file.txt.txt
15Post Visit Directory: D:\pankaj\java8\Files
16Post Visit Directory: D:\pankaj\java8
17Post Visit Directory: D:\pankaj