/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License, Version 1.0 only
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* (the "License"). You may not use this file except in compliance
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* with the License.
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*
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* You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
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* or http://forgerock.org/license/CDDLv1.0.html.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at legal-notices/CDDLv1_0.txt.
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* If applicable, add the following below this CDDL HEADER, with the
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* fields enclosed by brackets "[]" replaced with your own identifying
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* information:
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* Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*
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*
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* Copyright 2008 Sun Microsystems, Inc.
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*/
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package org.opends.quicksetup.util;
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import java.io.OutputStream;
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import java.io.IOException;
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import java.io.PrintStream;
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/**
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* Tool for suppressing and unsuppressing output to standard
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* output streams.
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*/
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public class StandardOutputSuppressor {
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static private Token token = null;
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/**
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* Object to return to this class for
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* unsupressing output.
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*/
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static private class Token {
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PrintStream out;
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PrintStream err;
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}
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/**
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* Suppresses output to the standard output
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* streams.
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*/
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static synchronized public void suppress() {
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if (token == null) {
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token = new Token();
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token.out = System.out;
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token.err = System.err;
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System.out.flush();
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System.err.flush();
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System.setOut(new PrintStream(new NullOutputStream()));
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System.setErr(new PrintStream(new NullOutputStream()));
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} else {
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throw new IllegalStateException("Standard streams currently suppressed");
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}
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}
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/**
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* Unsupresses the standard output streams. Following a call to this
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* method System.out and System.err will point to the descriptor prior
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* to calling <code>suppress()</code>.
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*/
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static synchronized public void unsuppress() {
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if (token != null) {
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System.setOut(token.out);
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System.setErr(token.err);
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token = null;
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} else {
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throw new IllegalStateException(
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"Standard streams not currently suppressed");
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}
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}
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/**
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* Checks whether or not this class has suppressed standard out streams.
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* @return boolean where true indicates output is suppressed
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*/
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static public boolean isSuppressed() {
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return token != null;
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}
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/**
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* PrintWriter for suppressing stream.
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*/
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static private class NullOutputStream extends OutputStream {
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/**
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* {@inheritDoc}
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*/
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public void write(int b) throws IOException {
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// do nothing;
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}
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}
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}
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