Java_IO

一.创建文件的三种方法

1.new File(String pathname)//根据路径构建一个File对象

 1 @Test
 2     public void create1(){
 3         String filePath = "D:\\file1.txt";
 4         File file = new File(filePath);
 5 
 6         try{
 7             file.createNewFile();
 8             System.out.println("创建文件1成功");
 9         }catch (IOException e){
10             e.printStackTrace();
11         }
12     }

 

2.new File(File parent,String child)//根据父目录文件+子路径构建

 1 @Test
 2     public void create2(){
 3         File parentFile = new File("D:\\");
 4         String fileName = "file2.txt";
 5         File file = new File(parentFile,fileName);
 6 
 7         try{
 8             file.createNewFile();
 9             System.out.println("创建文件2成功");
10         }catch (IOException e){
11             throw new RuntimeException(e);
12         }
13     }

 

 

3.new File(String parent,String child)//根据父目录+子路径构建

 1 @Test
 2     public void create3(){
 3         String parentPath = "d:\\";
 4         String filePath = "file3.txt";
 5         File file = new File(parentPath,filePath);
 6 
 7         try{
 8             file.createNewFile();
 9             System.out.println("创建文件3成功");
10         }catch (IOException e){
11             throw new RuntimeException(e);
12         }
13     }

 

二.文件信息的查询操作

 1 @Test
 2     public  void Info(){
 3         File file = new File("D:\\file1.txt");
 4         System.out.println("文件名称"+file.getName());
 5         System.out.println("文件绝对路径"+file.getAbsolutePath());
 6         System.out.println("文件父目录"+file.getParent());
 7         System.out.println("文件大小（字节）"+file.length());
 8         System.out.println("文件是否存在"+file.exists());
 9         System.out.println("是否是文件"+file.isFile());
10         System.out.println("是否是目录"+file.isDirectory());
11     }

 

三.文件夹的创建

 1 @Test
 2     public void fileDeleteD1(){
 3         String dirPath = "D:\\test\\dir1,txt";
 4         File file = new File(dirPath);
 5         if(file.exists()){
 6             System.out.println(dirPath+"该目录已经存在");
 7         }else{
 8             if(file.mkdir()){
 9                 System.out.println("创建成功");
10             }else{
11                 System.out.println("创建失败");
12             }
13         }
14     }

 

四.Scanner与Println

1 public static void main(String[] args) {
2         Scanner input = new Scanner(System.in);
3         String str = input.next();
4         System.out.println(str);
5         System.out.println("hello world");
6     }
 1 public static void main(String[] args) {
 2         Scanner input = new Scanner((System.in));
 3         System.out.print("请输入一个double类型的数");
 4         double d = input.nextDouble();
 5         System.out.println(d);
 6 
 7         System.out.print("请输入一个int类型的数");
 8         int i = input.nextInt();
 9         System.out.println(i);
10 
11         System.out.print("请输入一个string类型的数：");
12         String s = input.next();
13         System.out.println(s);
14     }

 

posted @ 2022-11-08 11:33  vasilizzz  阅读(33)  评论(0)    收藏  举报