JAVA学习--文件流FileReader和FileWriter应用

 1 @Test
 2     public void testFileReader(){
 3         FileReader fr = null;
 4         try {
 5             File file = new File("dbcp.txt");
 6             fr = new FileReader(file);
 7             char[] c = new char[24];
 8             int len;
 9             while((len = fr.read(c)) != -1){
10                 String str = new String(c, 0, len);
11                 System.out.print(str);
12             }
13         }catch (IOException e) {
14             // TODO Auto-generated catch block
15             e.printStackTrace();
16         }finally{
17             if(fr != null){
18                 try {
19                     fr.close();
20                 } catch (IOException e) {
21                     // TODO Auto-generated catch block
22                     e.printStackTrace();
23                 }
24             }
25         }
26         
27     }

 1     @Test
 2     public void testFileReaderWriter(){
 3         //1.输入流对应的文件src一定要存在，否则抛异常。输出流对应的文件dest可以不存在，执行过程中会自动创建
 4         FileReader fr = null;
 5         FileWriter fw = null;
 6         try{
 7             //不能实现非文本文件的复制
 8 //            File src = new File("C:\\Users\\shkstart\\Desktop\\1.jpg");
 9 //            File dest = new File("C:\\Users\\shkstart\\Desktop\\3.jpg");
10             File src = new File("dbcp.txt");
11             File dest = new File("dbcp1.txt");
12             //2.
13             fr = new FileReader(src);
14             fw = new FileWriter(dest);
15             //3.
16             char[] c = new char[24];
17             int len;
18             while((len = fr.read(c)) != -1){
19                 fw.write(c, 0, len);
20             }
21         }catch(Exception e){
22             e.printStackTrace();
23         }finally{
24             if(fw != null){
25                 try {
26                     fw.close();
27                 } catch (IOException e) {
28                     // TODO Auto-generated catch block
29                     e.printStackTrace();
30                 }
31             }
32             if(fr != null){
33                 try {
34                     fr.close();
35                 } catch (IOException e) {
36                     // TODO Auto-generated catch block
37                     e.printStackTrace();
38                 }
39             }
40         }
41     }