How to use PipedReader,pipeWriter, i has error output

[eric lee]

Why i can not output A,B,C? i got output "Error"
so how to change code? Thanks
-------------------------------------------------
import java.io.*;
class test {
public static void main(String args[])
{
PipedWriter out=new PipedWriter();
PipedReader input=new PipedReader();
char buffer[]={'A','B','C'};
int inChar;
try{
inChar=input.read(buffer);
while(inChar!=-1)
out.write(buffer,0,inChar);
}catch(IOException e){
System.out.println("Error");}
}
}

[Dirk Schreckmann]

What kind of error did you get? Was it a compiler error? Was it a runtime error? What did the error message say?

[eric lee]

the code got to excpetion and print "Error"

[Barry Gaunt]

I'm new to Java IO too, but I see these things:
1) Your PipedReader and PipedWriter have to be connected.
2) You should probably be writing into your PipedWriter before you read from your PipedReader.
3) Pipes are normally used between different threads

[Barry Gaunt]

Maybe this does what you are expecting:

 
import java.io.*;
class MyReader implements Runnable
{
    PipedReader in;
    
    MyReader( PipedReader in )
    {
        this.in = in;
    }
    
    public void run()
    {
        int inChar = 0;
        try
        {
            while ( (inChar = in.read()) != -1)
            {
                System.out.print((char)inChar);
            }
        System.out.println("\nDone");
        in.close(); 
        }
        catch ( IOException e )
        {
            e.printStackTrace();
        }
    }
}
class MyWriter implements Runnable
{
    PipedWriter out;
    char buffer[]={'A','B','C'};
    MyWriter( PipedWriter out )
    {
        this.out = out;
    }
    
    public void run()
    {
        try
        {
            out.write(buffer, 0, buffer.length);
            out.flush();
            out.close();
        }
        catch( IOException e )
        {
            e.printStackTrace();
        }
    }
}
class test
{
    public static void main(String args[])
    {
        PipedReader in=new PipedReader();
        PipedWriter out=new PipedWriter();
        try
        {
            in.connect(out);
            Thread writer = new Thread( new MyWriter( out ) );
            Thread reader = new Thread( new MyReader( in ) );
            writer.start();
            reader.start();
        }
        catch(IOException e)
        {
            e.printStackTrace();
            System.out.println("Error");
        }
    }
} 

Thank you for giving me the opportunity to learn about Piped IO and threads.
[ April 02, 2003: Message edited by: Barry Gaunt ]

[eric lee]

Thanks Barry Gaunt , i learn too!