CachingOutputStream


1   /*
2    * Copyright 1999-2004 The Apache Software Foundation.
3    * 
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    * 
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    * 
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.apache.cocoon.caching;
17  
18  import java.io.IOException  ;
19  import java.io.OutputStream  ;
20  
21  /**
22   * This is an {@link OutputStream} which forwards all received bytes to another
23   * output stream and in addition caches all bytes, thus acting like a
24   * TeeOutputStream.
25   *
26   * @author <a HREF="mailto:cziegeler@apache.org">Carsten Ziegeler</a>
27   * @version CVS $Id: CachingOutputStream.java 30932 2004-07-29 17:35:38Z vgritsenko $
28   */
29  
30  public final class CachingOutputStream
31  extends OutputStream   {
32  
33      private OutputStream   receiver;
34  
35      /** The buffer for the compile xml byte stream. */
36      private byte buf[];
37  
38      /** The number of valid bytes in the buffer. */
39      private int bufCount;
40  
41      public CachingOutputStream(OutputStream   os) {
42          this.receiver = os;
43          this.buf = new byte[1024];
44          this.bufCount = 0;
45      }
46  
47      public byte[] getContent() {
48          byte newbuf[] = new byte[this.bufCount];
49          System.arraycopy(this.buf, 0, newbuf, 0, this.bufCount);
50          return newbuf;
51      }
52  
53      public void write(int b) throws IOException   {
54          this.receiver.write(b);
55          int newcount = this.bufCount + 1;
56          if (newcount > this.buf.length) {
57              byte newbuf[] = new byte[Math.max(this.buf.length << 1, newcount)];
58              System.arraycopy(this.buf, 0, newbuf, 0, this.bufCount);
59              this.buf = newbuf;
60          }
61          this.buf[this.bufCount] = (byte)b;
62          this.bufCount = newcount;
63      }
64  
65      public void write( byte b[] ) throws IOException   {
66          this.write(b, 0, b.length);
67      }
68  
69      public void write(byte b[], int off, int len) throws IOException   {
70          this.receiver.write(b, off, len);
71          if (len == 0) return;
72          int newcount = this.bufCount + (len-off);
73          if (newcount > this.buf.length) {
74              byte newbuf[] = new byte[Math.max(this.buf.length << 1, newcount)];
75              System.arraycopy(this.buf, 0, newbuf, 0, this.bufCount);
76              this.buf = newbuf;
77          }
78          System.arraycopy(b, off, this.buf, this.bufCount, len);
79          this.bufCount = newcount;
80      }
81  
82      public void flush() throws IOException   {
83          this.receiver.flush();
84      }
85  
86      public void close() throws IOException   {
87          this.receiver.close();
88      }
89  
90  
91  }
92
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