JAVA学习--文件File的操作

  1 public class TestFile {
  2     /*
  3      *  createNewFile()
  4         delete()
  5         mkDir():创建一个文件目录。只有在上层文件目录存在的情况下，才能返回true
  6         mkDirs():创建一个文件目录。若上层文件目录不存在，一并创建
  7         list()
  8         listFiles()
  9      */
 10     @Test
 11     public void test3() throws IOException{
 12         File file1 = new File("d:/io/helloworld.txt");
 13         System.out.println(file1.delete());
 14         
 15         if(!file1.exists()){
 16             boolean b = file1.createNewFile();
 17             System.out.println(b);
 18         }
 19         
 20         File file2 = new File("d:\\io1\\io2");
 21         if(!file2.exists()){
 22             boolean b = file2.mkdirs();
 23             System.out.println(b);
 24         }
 25         
 26         File file3 = new File("d:\\teach");
 27         String[] strs = file3.list();
 28         for(int i = 0;i < strs.length;i++){
 29             System.out.println(strs[i]);
 30         }
 31         
 32         System.out.println();
 33         
 34         File[] files = file3.listFiles();
 35         for(int i = 0;i < files.length;i++){
 36             System.out.println(files[i].getName());
 37         }
 38     }
 39     
 40     /*
 41      *  exists()
 42         canWrite()
 43         canRead()
 44         isFile()
 45         isDirectory()
 46         lastModified()
 47         length()
 48 
 49      */
 50     @Test
 51     public void test2(){
 52         File file1 = new File("d:/io/helloworld.txt");
 53         File file2 = new File("d:\\io\\io1");
 54         
 55         System.out.println(file1.exists());
 56         System.out.println(file1.canWrite());
 57         System.out.println(file1.canRead());
 58         System.out.println(file1.isFile());
 59         System.out.println(file1.isDirectory());
 60         System.out.println(new Date(file1.lastModified()));
 61         System.out.println(file1.length());
 62         
 63         System.out.println();
 64         
 65         System.out.println(file2.exists());
 66         System.out.println(file2.canWrite());
 67         System.out.println(file2.canRead());
 68         System.out.println(file2.isFile());
 69         System.out.println(file2.isDirectory());
 70         System.out.println(new Date(file2.lastModified()));
 71         System.out.println(file2.length());
 72     
 73     }
 74     
 75     /*
 76      * 路径：
 77      * 绝对路径：包括盘符在内的完整的文件路径
 78      * 相对路径：在当前文件目录下的文件的路径
 79      * 
 80      *  getName()
 81         getPath()
 82         getAbsoluteFile()
 83         getAbsolutePath()
 84         getParent()
 85         renameTo(File newName)
 86 
 87      */
 88     @Test
 89     public void test1(){
 90         File file1 = new File("d:/io/helloworld.txt");
 91         File file2 = new File("hello1.txt");
 92         
 93         File file3 = new File("d:\\io\\io1");
 94         File file4 = new File("d:\\io2");
 95         
 96         System.out.println(file1.getName());
 97         System.out.println(file1.getPath());
 98         System.out.println(file1.getAbsoluteFile());
 99         System.out.println(file1.getParent());
100         System.out.println(file1.getAbsolutePath());
101         
102         System.out.println();
103         
104         System.out.println(file3.getName());
105         System.out.println(file3.getPath());
106         System.out.println(file3.getAbsoluteFile());
107         System.out.println(file3.getParent());
108         System.out.println(file3.getAbsolutePath());
109         
110         //renameTo(File newName):重命名
111         //file1.renameTo(file2):file1重命名为file2.要求：file1文件一定存在，file2一定不存在
112         boolean b = file1.renameTo(file2);
113         System.out.println(b);
114         
115         boolean b1 = file4.renameTo(file3);
116         System.out.println(b1);
117     }