Java APIs

I now got a unsolute problem about the io stream close and reopen again in one program,this will pop exception:
source code is in following:
//-----------------------------------------------------------------------------------------------------------------
import java.io.*;

public class IOTest{
public static void main(String args[]){
try{
BufferedReader in3=null;
BufferedReader in2 = new BufferedReader(new InputStreamReader(System.in));;
String s=in2.readLine();
System.out.println(s);
System.out.println("input another:");

in2.close();
System.out.println("close in2,then renew a in2");
in2 = new BufferedReader(new InputStreamReader(System.in));
System.out.println("after 2nd in2 new");
s=in2.readLine();
System.out.println(s);

}catch(Exception e){
System.out.println(e.getMessage());
e.printStackTrace();
}
}
}
//--------------------------------------------------------------------------------------------------------
and running exception is in following:
//--------------------------------------------------------------------------------------------------------
C:\>java IOTest
ddd
ddd
input another:
close in2,then renew a in2
after 2nd in2 new
Stream closed
java.io.IOException: Stream closed
at java.io.BufferedInputStream.ensureOpen(BufferedInputStream.java:120)
at java.io.BufferedInputStream.read(BufferedInputStream.java:270)
at java.io.FilterInputStream.read(FilterInputStream.java:90)
at sun.nio.cs.StreamDecoder$ConverterSD.implRead(StreamDecoder.java:282)

at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:179)
at java.io.InputStreamReader.read(InputStreamReader.java:167)
at java.io.BufferedReader.fill(BufferedReader.java:136)
at java.io.BufferedReader.readLine(BufferedReader.java:299)
at java.io.BufferedReader.readLine(BufferedReader.java:362)
at IOTest.main(IOTest.java:16)
//----------------------------------------------------------------------------------------------------------------------
wanted somebody to solute this problem or tell me why,
I use java version "1.4.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1
Java HotSpot(TM) Client VM (build 1.4.0-b92, mixed mode)
thanks first.
apachegu@163.com