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1   /*
2    * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
3    * The software in this package is published under the terms of the CPAL v1.0
4    * license, a copy of which has been included with this distribution in the
5    * LICENSE.txt file.
6    */
7   package org.mule.util;
8   
9   import java.io.IOException;
10  import java.io.Reader;
11  
12  /**
13   * <code>ChainedReader</code> allows Reader objects to be chained together. Useful
14   * for concatenating data from multiple Reader objects.
15   */
16  public class ChainedReader extends Reader
17  {
18      private final Reader first;
19      private final Reader second;
20      private boolean firstRead = false;
21  
22      public ChainedReader(Reader first, Reader second)
23      {
24          this.first = first;
25          this.second = second;
26      }
27  
28      public void close() throws IOException
29      {
30          first.close();
31          second.close();
32      }
33  
34      public int read(char[] cbuf, int off, int len) throws IOException
35      {
36          if (!firstRead)
37          {
38              int i = first.read(cbuf, off, len);
39              if (i < len)
40              {
41                  firstRead = true;
42                  int x = second.read(cbuf, i, len - i);
43                  return x + i;
44              }
45              else
46              {
47                  return i;
48              }
49          }
50          else
51          {
52              return second.read(cbuf, off, len);
53          }
54      }
55  
56      public int read() throws IOException
57      {
58          if (!firstRead)
59          {
60              int i = first.read();
61              if (i == -1)
62              {
63                  firstRead = true;
64                  return second.read();
65              }
66              else
67              {
68                  return i;
69              }
70          }
71          else
72          {
73              return second.read();
74          }
75      }
76  
77      public int read(char[] cbuf) throws IOException
78      {
79          if (!firstRead)
80          {
81              int i = first.read(cbuf);
82              if (i < cbuf.length)
83              {
84                  firstRead = true;
85                  int x = second.read(cbuf, i, cbuf.length - i);
86                  return x + i;
87              }
88              else
89              {
90                  return i;
91              }
92          }
93          else
94          {
95              return second.read(cbuf);
96          }
97      }
98  
99  }