iodemo.out

学习参考,java基本语法练习,包括一些常用的技巧

1: import java.io.*;
2: public class SystemInOutDemo 
3: {
4: 	public static void samples() throws IOException
5:       {
6:            //1. 这是从键盘读入一行数据,返回的是一个字符串
7:            BufferedReader stdin =new BufferedReader(new InputStreamReader(System.in)); 
8:            System.out.print("Enter a line:");
9:            System.out.println(stdin.readLine());
10:            //2. 这是从文件中逐行读入数据 
11:            BufferedReader in = new BufferedReader(new FileReader("SystemInOutDemo.java"));
12:            String s, s2 = new String();
13:            while((s = in.readLine())!= null)
14:                       s2 += s + "\n";
15:            in.close();
16:            //3. 这是从一个字符串中逐个读入字节 
17:            StringReader in1 = new StringReader(s2);
18:            int c;
19:            while((c = in1.read()) != -1)
20:                       System.out.print((char)c);
21:            //4. 这是将一个字符串写入文件 
22:            try 
23:            {
24: 				BufferedReader in2 = new BufferedReader(new StringReader(s2));
25: 				PrintWriter out1 = new PrintWriter(new BufferedWriter(new FileWriter("IODemo.out")));
26: 				int lineCount = 1;
27: 				while((s = in2.readLine()) != null )
28: 					out1.println(lineCount++ + ": " + s);
29: 				out1.close();
30:            	} catch(EOFException e) 
31:            	{
32:                       System.err.println("End of stream");
33:            	}
34:       }
35:       public static void main(String args[]) throws IOException
36:       {
37:     		samples();  		
38:       }
39: }