gogo/src/org/osgi/service/threadio/ThreadIO.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.osgi.service.threadio;

import java.io.*;

/**
 * Enable multiplexing of the standard IO streams for input, output, and error.
 * 
 * This service guards the central resource of IO streams. The standard streams
 * are singletons. This service replaces the singletons with special versions that
 * can find a unique stream for each thread. If no stream is associated with a
 * thread, it will use the standard input/output that was originally set.
 * 
 * @author aqute
 *
 */
public interface ThreadIO {
	/**
	 * Associate this streams with the current thread.
	 * 
	 * Ensure that when output is performed on System.in, System.out, System.err it
	 * will happen on the given streams. 
	 * 
	 * The streams will automatically be canceled when the bundle that has gotten
	 * this service is stopped or returns this service.
	 * 
	 * @param in InputStream to use for the current thread when System.in is used
	 * @param out PrintStream to use for the current thread when System.out is used
	 * @param err PrintStream to use for the current thread when System.err is used
	 */
	void setStreams(InputStream in, PrintStream out, PrintStream err);

	/**
	 * Cancel the streams associated with the current thread.
	 * 
	 * This method will not do anything when no streams are associated.
	 */
	void close();
}