java file

 @Test
    public void test1(){
        File file1 = new File("/Users/truman/Desktop/Life");
        System.out.println(file1);
        System.out.println(file1.isDirectory());

        File file2 = new File("/Users/truman", "Pictures");
        System.out.println(file2);
        System.out.println(file2.isDirectory());

        File file3 = new File(file2, "aiaiai.jpg");
        System.out.println(file3);
    }

Common Methods

String getAbsolutePath()

String getPath()

String getName()

String getParent()

long length()

long lastModified()

@Test
    public void testFileMethod(){
        File file1 = new File("/Users/truman/Desktop");

        System.out.println(file1.getAbsolutePath()); // /Users/truman/Desktop
        System.out.println(file1.getPath());  // /Users/truman/Desktop
        System.out.println(file1.getName()); // Desktop
        System.out.println(file1.getParent()); // /Users/truman
        System.out.println(file1.length());  // 672
        System.out.println(file1.lastModified());  // 1593138078000  
        System.out.println(new Date(file1.lastModified()));  // Fri Jun 26 10:21:18 CST 2020
        
    }

String[] list()

String[] list = file1.list();
        System.out.println(Arrays.toString(list));
// [Villanelle, Database, 数学建模书籍, .DS_Store, Something, .localized, ...]

FIle[] listFiles()

File[] files = file1.listFiles();

boolean renameTo(File file) (实际上是移动文件）

More Methods

boolean createNewFile()

@Test
    public void testCreateFile(){
        File file1 = new File("hi.txt");
        if(!file1.exists()){
            try {
                file1.createNewFile();
                System.out.println("New File Created.");
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

 

boolean delete()

   @Test
    public void testDelete(){
        File file1 = new File("hi.txt");
        if (file1.exists()){
            file1.delete();
            System.out.println("File Deleted.");
        }
    }
}