1 package Head18;
 2 
 3 import java.io.BufferedReader;
 4 import java.io.File;
 5 import java.io.FileNotFoundException;
 6 import java.io.FileReader;
 7 import java.io.FileWriter;
 8 import java.io.IOException;
 9 
10 public class Mkdirs_FileRW {
11     public static void main(String [] args) {
12
 
         String a0="D:\\abc";
13         String a1=a0+"\\abc.txt";
14         File file0= new File(a0); 
15         File file = new File(a1);
16         file0.mkdirs();
17         //創建文件    
18         if (!file.exists()){
19             try {
20                 file.createNewFile();
21                 System.out.println("文件創建成功");
 
22             } catch (IOException e) {
23             
24                 e.printStackTrace();
25             }
26         }else{
27             System.out.println("文件已經存在");
28         
29         }
30         
31         //寫文件
32         try {
33             FileWriter fWriter = new FileWriter(a1, true
 
);
34             fWriter.write("測試0"+"\r\n");;
35             fWriter.flush();
36             fWriter.close();
37         } catch (IOException e) {
38             // TODO Auto-generated catch block
39             e.printStackTrace();
40         }
41         
42         //讀文件
43         try {
44             FileReader fReader=new FileReader(file);
45             //字符流
46             BufferedReader bfReader=new BufferedReader(fReader);
47             try {
48                 String bf=null;
49                 while((bf=bfReader.readLine())!=null){
50                     System.out.println(bf);
51                 }
52                 
53             } catch (IOException e) {
54                 e.printStackTrace();
55             }
56         } catch (FileNotFoundException e) {
57             e.printStackTrace();
58         }
59         
60         
61         
62         
63         
64     }
65 }

java創建文本、文件、讀文件、寫文件