1   /*
2    * Logback: the reliable, generic, fast and flexible logging framework.
3    * Copyright (C) 1999-2022, QOS.ch. All rights reserved.
4    *
5    * This program and the accompanying materials are dual-licensed under
6    * either the terms of the Eclipse Public License v1.0 as published by
7    * the Eclipse Foundation
8    *
9    *   or (per the licensee's choosing)
10   *
11   * under the terms of the GNU Lesser General Public License version 2.1
12   * as published by the Free Software Foundation.
13   */
14  package ch.qos.logback.core.testUtil;
15  
16  import java.io.ByteArrayOutputStream;
17  import java.io.IOException;
18  import java.io.OutputStream;
19  import java.io.PrintStream;
20  
21  /**
22   * This stream writes its output to the target PrintStream supplied to its
23   * constructor. At the same time, all the available bytes are collected and
24   * returned by the toString() method.
25   * 
26   * @author Ceki Gulcu
27   */
28  public class TeeOutputStream extends OutputStream {
29  
30      final PrintStream targetPS;
31      public final ByteArrayOutputStream baos = new ByteArrayOutputStream();
32  
33      public TeeOutputStream(PrintStream targetPS) {
34          // allow for null arguments
35          this.targetPS = targetPS;
36      }
37  
38      public void write(int b) throws IOException {
39          baos.write(b);
40          if (targetPS != null) {
41              targetPS.write(b);
42          }
43      }
44  
45      public String toString() {
46          return baos.toString();
47      }
48  
49      public byte[] toByteArray() {
50          return baos.toByteArray();
51      }
52  }