//这是一个字节流的例子，以inputstream与outputstream为基础类

import java.io.*;

class bytearrayoutputstreamdemo {

    public static void main(string args[]) throws ioexception {

    bytearrayoutputstream f = new bytearrayoutputstream();

    string s = "this should end up in the array";

    byte buf[] = s.getbytes();

    f.write(buf);

        system.out.println("buffer as a string");

        system.out.println(f.tostring());

        system.out.println("into array");

    byte b[] = f.tobytearray();

    for (int i=0; i<b.length; i++) {

        system.out.print((char) b[i]);}

        system.out.println("/nto an outputstream()");

        //输出到文件test.txt中

        outputstream f2 = new fileoutputstream("test.txt");

        f.writeto(f2);

        f2.close();

        system.out.println("doing a reset");

        f.reset();

    for (int i=0; i<3; i++)

    f.write('x');

        system.out.println(f.tostring());}}

//字符流的例子，以reader与writer为基础类

import java.io.*;

public class chararrayreaderdemo {

   public static void main(string args[]) throws ioexception {

   string tmp = "abcdefghijklmnopqrstuvwxyz";

   int length = tmp.length();

   char c[] = new char[length];

   tmp.getchars(0, length, c, 0);

   chararrayreader input1 = new chararrayreader(c);

   chararrayreader input2 = new chararrayreader(c, 0, 5);

   int i;

       system.out.println("input1 is:");

   while((i = input1.read()) != -1) {

       system.out.print((char)i);}

       system.out.println();

       system.out.println("input2 is:");

   while((i = input2.read()) != -1) {

       system.out.print((char)i);}

       system.out.println();

   }}

//文件流的例子

import java.io.*;

class fileinputstreamdemo {

   public static void main(string args[]) throws exception {

   int size;

   inputstream f =

   new fileinputstream("fileinputstreamdemo.java");

       system.out.println("total available bytes: " +

       (size = f.available()));

   int n = size/40;

       system.out.println("first " + n +

       " bytes of the file one read() at a time");

   for (int i=0; i < n; i++) {

       system.out.print((char) f.read());

       }

       system.out.println("/nstill available: " + f.available());

       system.out.println("reading the next " + n +

       " with one read(b[])");

   byte b[] = new byte[n];

   if (f.read(b) != n) {

       system.err.println("couldn't read " + n + " bytes.");

       }

       system.out.println(new string(b, 0, n));

       system.out.println("/nstill available: " + (size = f.available()));

       system.out.println("skipping half of remaining bytes with skip()");

   f.skip(size/2);

       system.out.println("still available: " + f.available());

       system.out.println("reading " + n/2 + " into the end of array");

   if (f.read(b, n/2, n/2) != n/2) {

       system.err.println("couldn't read " + n/2 + " bytes.");

       }

       system.out.println(new string(b, 0, b.length));

       system.out.println("/nstill available: " + f.available());

   f.close();

   }

}