Path operation

1. Delete files
 
2. Traversing directories, excluding subdirectories

    Path dir = Paths.get("F:\\LZ\\pdf");
    DirectoryStream<Path> stream = Files.newDirectoryStream(dir);
    for(Path path : stream){
        System.out.println(path.getFileName());
    }

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2. Traversing directories and files in their subdirectories

    Path dir = Paths.get("F:\\LZ\\pdf");
    Files.walkFileTree(dir,new SimpleFileVisitor<Path>(){
        @Override
        public FileVisitResult visitFile(Path file, BasicFileAttributes attrs)
                throws IOException {
            if(file.toString().endsWith(".pdf")){
                System.out.println(file.getFileName());
            }
            return super.visitFile(file, attrs);
        }
    });

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3. Create multilevel directories

    Path dir = Paths.get("F:\\LZ\\xx\\dd");
    Files.createDirectories(dir);

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4. Create a file and throw an exception if it does not exist

    Path dir = Paths.get("F:\\LZ\\xx\\dd\\1.txt");
    Files.createFile(dir);

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5. File duplication

    Path src = Paths.get("F:\\LZ\\xx\\dd\\1.txt");
    Path target = Paths.get("F:\\LZ\\xx\\dd\\2.txt");

    //REPLACE_EXISTING: Files exist and are replaced
    Files.copy(src, target,StandardCopyOption.REPLACE_EXISTING);

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6. Read files line by line

    Path src = Paths.get("F:\\LZ\\xx\\dd\\1.txt");
    BufferedReader reader = Files.newBufferedReader(src,StandardCharsets.UTF_8);
    String line ;
    while((line=reader.readLine()) != null){
        System.out.println(line);
    }
    reader.close();

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7. Write strings

    Path src = Paths.get("F:\\LZ\\xx\\dd\\1.txt");
    BufferedWriter writer = Files.newBufferedWriter(src, StandardCharsets.UTF_8
            ,StandardOpenOption.APPEND); // Append
    writer.write("hello word Path");
    writer.close();

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8. Binary reads and writes are similar to strings

1. A method to extract strings and binary streams directly

    // Character string
    Path src = Paths.get("F:\\LZ\\xx\\dd\\1.txt");
    for(String line : Files.readAllLines(src)){
        System.out.println(line);
    }
    // Binary stream
    byte[] bytes = Files.readAllBytes(src);

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10. Monitor whether files in directories are modified, created, or deleted.

11. Read the last 1000 characters of the file

Official documents: http://docs.oracle.com/javase/7/docs/index.html

When I learned how to use Lucene 5.0, I found that I could not click on Path at any point. Later, I found something inside JDK7 on the internet. Then I went to get Path objects myself, but I didn't know how to get Path. So I went to find out how to get Path. I found this article, demonstrated it in person, and published it in the hope that it would be helpful.

Examples are as follows:

1. package com.darren.test.jdk7;  
2.   
3. import java.io.BufferedReader;  
4. import java.io.File;  
5. import java.io.IOException;  
6. import java.nio.charset.Charset;  
7. import java.nio.file.FileSystems;  
8. import java.nio.file.Files;  
9. import java.nio.file.Path;  
10. import java.nio.file.Paths;  
11.   
12. /** 
13.  * Path It is an important entry point for file operations in the nio.file package of Java 1.7. As a basis, it is necessary to understand 
14.  */  
15. public class PathTest {  
16.     public static void main(String[] args) {  
17.         //Get path method 1, F:/test/jdk7/test.txt  
18.         Path path = FileSystems.getDefault().getPath("F:/test/jdk7", "test.txt");  
19.         //Number of Node Layers where Printed Files Are Located  
20.         System.out.println(path.getNameCount());  
21.   
22.         //Get path method 2 and get Path objects by File's toPath() method  
23.         File file = new File("F:/test/jdk7/test.txt");  
24.         Path pathOther = file.toPath();  
25.         //0, indicating that the two path s are equal  
26.         System.out.println(path.compareTo(pathOther));  
27.   
28.         //Obtaining path method 3  
29.         Path path3 = Paths.get("F:/test/jdk7", "test.txt");  
30.         System.out.println(path3.toString());  
31.   
32.         // join two paths  
33.         Path path4 = Paths.get("F:/test/jdk7");  
34.         System.out.println("path4: " + path4.resolve("test.txt"));  
35.         System.out.println("--------------Dividing line---------------");  
36.   
37.         try {  
38.             if (Files.isReadable(path)) {  
39.                 //Note that the charset parameter of newBufferedRead here throws an exception if it does not correspond to the encoding of the file to be read  
40.                 //New features of java that do not shut down streams by themselves  
41.                 BufferedReader br = Files.newBufferedReader(path, Charset.defaultCharset());  
42.                 // new BufferedReader(new FileReader(new File("F:/test/jdk7/test.txt")));  
43.                 String line = "";  
44.                 while ((line = br.readLine()) != null) {  
45.                     System.out.println(line);  
46.                 }  
47.             } else {  
48.                 System.err.println("cannot readable");  
49.             }  
50.         } catch (IOException e) {  
51.             System.err.println("error charset");  
52.         }  
53.     }  
54. }  

Operation results:

1. 3  
2. 0  
3. F:\test\jdk7\test.txt  
4. path4: F:\test\jdk7\test.txt  
5. --------------Dividing line---------------  
6. I am Darren