/*
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* The contents of this file are subject to the terms of the Common Development and
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* Distribution License (the License). You may not use this file except in compliance with the
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* License.
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*
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* You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
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* specific language governing permission and limitations under the License.
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*
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* When distributing Covered Software, include this CDDL Header Notice in each file and include
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* the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
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* Header, with the fields enclosed by brackets [] replaced by your own identifying
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* information: "Portions Copyright [year] [name of copyright owner]".
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*
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* Copyright 2008 Sun Microsystems, Inc.
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* Portions Copyright 2015-2016 ForgeRock AS.
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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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/** Tool for suppressing and unsuppressing output to standard output streams. */
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public class StandardOutputSuppressor {
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private static Token token;
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/** Object to return to this class for unsuppressing output. */
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private static class Token {
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PrintStream out;
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PrintStream err;
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}
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/** Suppresses output to the standard output streams. */
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public static synchronized 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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* Unsuppresses 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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public static synchronized 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 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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public static boolean isSuppressed() {
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return token != null;
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}
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/** PrintWriter for suppressing stream. */
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private static class NullOutputStream extends OutputStream {
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@Override
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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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