Java IO流几种经典使用方式

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package Test;

import java.io.*;

public class Test{
     public static void main(String[] args) throws IOException{
         //reading input by lines from file
         BufferedReader in=new BufferedReader(
                 new FileReader(
                 "E:\\JavaProgram\\Test\\src\\test\\Test.java"));
         String s,s2=new String();
         while((s=in.readLine())!=null) s2+=s+"\n";
         System.out.println(s2);
         in.close();

         //从标准输入读入(键盘)
         BufferedReader stdin=new BufferedReader(new InputStreamReader(System.in));
         System.out.print("Enter a line:");
         stdin.skip(10);
         String si=stdin.readLine();
         System.out.println(s);
         stdin.close();

         //从内存变量读入
         StringReader in2=new StringReader(s2);
         int c;
         while((c=in2.read())!=-1)
             System.out.print((char)c);

         //从格式化内存读入
         try{
             DataInputStream in3=new DataInputStream(
                     new ByteArrayInputStream(s2.getBytes()));
             while(true)
                 System.out.print((char)in3.readByte()+"\n");
         }catch(EOFException e){
             System.err.println("End of stream");
         }


         //输出到文件
         try{
             BufferedReader in4=new BufferedReader(new StringReader(s2));
             PrintWriter out1=new PrintWriter(
                     new BufferedWriter(new FileWriter("IODemo.out")));
             int lineCount=1;
             while((s=in4.readLine())!=null) out1.println(lineCount++ +":"+s);
             out1.close();
         }catch(EOFException e){
             System.err.println("End of stream");
         }

         //存储覆盖数据到文件
         try{
             DataOutputStream out2=new DataOutputStream(
                     new BufferedOutputStream(
                     new FileOutputStream("Data.txt")));
             out2.writeDouble(3.14159);
             out2.writeUTF("that is pi");
             out2.close();
             DataInputStream in5=new DataInputStream(
                     new BufferedInputStream(
                     new FileInputStream("Data.txt")));
             System.out.println(in5.readDouble());
             System.out.println(in5.readUTF());
         }catch(EOFException e){
             throw new RuntimeException(e);
         }

         //reading/writing random access files随机读取和输出到文件
         RandomAccessFile rf=new RandomAccessFile("rtest.dat","rw");
         for(int i=0;i<10;i++)   rf.writeDouble(i*1.414);
         rf.writeUTF("fuck you");
         rf.close();
         rf=new RandomAccessFile("rtest.dat","rw");
         rf.seek(5*8);
         rf.writeDouble(47.0001);
         rf.close();
         rf=new RandomAccessFile("rtest.dat","r");
         for(int i=0;i<10;i++) System.out.println("value "+i+": "+rf.readDouble());
         System.out.println(rf.readUTF());
         rf.close();
     }
}

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