IO 输入输出 Reader

 1 public class FileReaderDemo {
 2     public static void main(String[] args) {
 3         File file = new File("f:\\test");
 4         if (!file.exists()) {
 5             file.mkdirs();
 6         }
 7         String r = file.getAbsolutePath() + "\\1.txt";
 8         String w = file.getAbsolutePath() + "\\2.txt";
 9         FileWriter fw = null;
10         FileReader fr = null;
11         try {
12             fr = new FileReader(r);
13             fw = new FileWriter(w);
14             int len = 0;
15             while ((len = fr.read()) !=-1) {
16                 fw.write(len);
17             }
18 //            fw.write("abc");
19         } catch (IOException e) {
20             e.printStackTrace();
21         } finally {
22             try {
23                 fr.close();
24                 fw.close();
25             } catch (IOException e) {
26                 e.printStackTrace();
27             }
28         }
29     }
30 }