| /* |
| * 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 |
| * |
| * https://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.apache.tools.ant.util; |
| |
| import java.io.FilterOutputStream; |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.io.PrintStream; |
| |
| /** |
| * Class that can be used to wrap <code>System.out</code> and <code>System.err</code> |
| * without getting anxious about any client closing the stream. |
| * |
| * <p> |
| * In code-language it means that it is not necessary to do: |
| * <pre> |
| * if (out != System.out && out != System.err) { |
| * out.close(); |
| * } |
| * </pre> |
| * |
| */ |
| public class KeepAliveOutputStream extends FilterOutputStream { |
| |
| /** |
| * Constructor of KeepAliveOutputStream. |
| * |
| * @param out an OutputStream value, it should be standard output. |
| */ |
| public KeepAliveOutputStream(OutputStream out) { |
| super(out); |
| } |
| |
| /** |
| * This method does nothing. |
| * @throws IOException as we are overriding FilterOutputStream. |
| */ |
| public void close() throws IOException { |
| // do not close the stream |
| } |
| |
| /** |
| * Convenience factory method that returns a non-closing |
| * PrintStream around System.out. |
| * |
| * @return PrintStream |
| * @since Ant 1.8.0 |
| */ |
| public static PrintStream wrapSystemOut() { |
| return wrap(System.out); |
| } |
| |
| /** |
| * Convenience factory method that returns a non-closing |
| * PrintStream around System.err. |
| * |
| * @return PrintStream |
| * @since Ant 1.8.0 |
| */ |
| public static PrintStream wrapSystemErr() { |
| return wrap(System.err); |
| } |
| |
| /** |
| * @return PrintStream |
| * @since Ant 1.8.0 |
| */ |
| private static PrintStream wrap(PrintStream ps) { |
| return new PrintStream(new KeepAliveOutputStream(ps)); |
| } |
| } |