/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
* or http://forgerock.org/license/CDDLv1.0.html.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at legal-notices/CDDLv1_0.txt.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information:
* Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*
*
* Copyright 2008 Sun Microsystems, Inc.
* Portions Copyright 2015 ForgeRock AS
*/
package org.opends.quicksetup.util;
import java.io.OutputStream;
import java.io.IOException;
import java.io.PrintStream;
/**
* Tool for suppressing and unsuppressing output to standard
* output streams.
*/
public class StandardOutputSuppressor {
private static Token token;
/** Object to return to this class for unsuppressing output. */
private static class Token {
PrintStream out;
PrintStream err;
}
/** Suppresses output to the standard output streams. */
public static synchronized void suppress() {
if (token == null) {
token = new Token();
token.out = System.out;
token.err = System.err;
System.out.flush();
System.err.flush();
System.setOut(new PrintStream(new NullOutputStream()));
System.setErr(new PrintStream(new NullOutputStream()));
} else {
throw new IllegalStateException("Standard streams currently suppressed");
}
}
/**
* Unsuppresses the standard output streams. Following a call to this
* method System.out and System.err will point to the descriptor prior
* to calling <code>suppress()</code>.
*/
public static synchronized void unsuppress() {
if (token != null) {
System.setOut(token.out);
System.setErr(token.err);
token = null;
} else {
throw new IllegalStateException(
"Standard streams not currently suppressed");
}
}
/**
* Checks whether or not this class has suppressed standard out streams.
* @return boolean where true indicates output is suppressed
*/
public static boolean isSuppressed() {
return token != null;
}
/**
* PrintWriter for suppressing stream.
*/
private static class NullOutputStream extends OutputStream {
/** {@inheritDoc} */
public void write(int b) throws IOException {
// do nothing;
}
}
}