Re: Why should close() close the underlying stream?

From:
=?ISO-8859-1?Q?Arne_Vajh=F8j?= <arne@vajhoej.dk>
Newsgroups:
comp.lang.java.programmer
Date:
Wed, 24 Oct 2007 21:53:37 -0400
Message-ID:
<471ff713$0$90267$14726298@news.sunsite.dk>
Eric Sosman wrote:

Daniel Pitts wrote:

Eric Sosman wrote:

[...] If desired you could add a reallyClose() method
that forwards to super.close(), and/or a getActualStream()
method that returns the superclass instance.


You can't return a superclass instance, [...]


    Gugghh! You're right, of course; sorry for the red
herring.


Something similar can be made to work.

package october;

import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintStream;

public class NonClosingStream extends OutputStream {
     private OutputStream real;
     public NonClosingStream(OutputStream real) {
         this.real = real;
     }
     public void close() throws IOException {
         // ignore
     }
     public void realclose() throws IOException {
         real.close();
     }
     public boolean equals(Object obj) {
         return real.equals(obj);
     }
     public void flush() throws IOException {
         real.flush();
     }
     public int hashCode() {
         return real.hashCode();
     }
     public String toString() {
         return real.toString();
     }
     public void write(byte[] b, int off, int len) throws IOException {
         real.write(b, off, len);
     }
     public void write(byte[] b) throws IOException {
         real.write(b);
     }
     public void write(int b) throws IOException {
         real.write(b);
     }
     public static void main(String[] args) throws IOException {
         // OutputStream os = new FileOutputStream("C:\\z.z");
         NonClosingStream os = new NonClosingStream(new
FileOutputStream("C:\\z.z"));
         PrintStream ps = new PrintStream(os);
         ps.println("Hello");
         ps.close();
         PrintStream ps2 = new PrintStream(os);
         ps2.println("Hello");
         ps2.close();
         os.realclose();
     }
}

Arne

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