java 獲取檔案大小

woff

1. import java.io.*;
   
2. public class Filee {
   
3. public static void main(String[] args) throws IOException {
   
4.    File f = new File("C:\\Downloads\\plato_free070821.rar");
   
5.    if (f.exists()) {
   
6. /** ///1 可以   
   
7. *
   
8. * FileInputStream fis = null;
   
9.     fis = new FileInputStream(f);
   
10.     System.out.println("File has " + fis.available()
    
11.       + " bytes");
    
12.     System.out.println("File has " + (double)((double)fis.available()/1000/1000)
    
13.       + "M");
    
14.     System.out.println("File has " + (double)(fis.available()/1024/1024)
    
15.       + "M");*/
    
16.     /** ///2 可以
    
17.     * System.out.println("文件存在");
    
18.     * System.out.println("文件大小为:"+(double)(f.length()/1024/1024)+"M");
    
19.     */
    
20.    } else {
    
21.     f.createNewFile();
    
22.     System.out.println("文件不存在");
    
23.    }
    
24. }
    
25. }

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