1 | /**************************************************************** |
2 | * Licensed to the Apache Software Foundation (ASF) under one * |
3 | * or more contributor license agreements. See the NOTICE file * |
4 | * distributed with this work for additional information * |
5 | * regarding copyright ownership. The ASF licenses this file * |
6 | * to you under the Apache License, Version 2.0 (the * |
7 | * "License"); you may not use this file except in compliance * |
8 | * with the License. You may obtain a copy of the License at * |
9 | * * |
10 | * http://www.apache.org/licenses/LICENSE-2.0 * |
11 | * * |
12 | * Unless required by applicable law or agreed to in writing, * |
13 | * software distributed under the License is distributed on an * |
14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * |
15 | * KIND, either express or implied. See the License for the * |
16 | * specific language governing permissions and limitations * |
17 | * under the License. * |
18 | ****************************************************************/ |
19 | |
20 | package org.apache.james.jdkim.canon; |
21 | |
22 | import java.io.FilterOutputStream; |
23 | import java.io.IOException; |
24 | import java.io.OutputStream; |
25 | |
26 | /** |
27 | * Pass data to the underlying system until a given amount of bytes is reached. |
28 | */ |
29 | public class LimitedOutputStream extends FilterOutputStream { |
30 | |
31 | private int limit; |
32 | private int computedBytes; |
33 | |
34 | /** |
35 | * @param out |
36 | * an output stream that will receive the "trucated" stream. |
37 | * @param limit |
38 | * a positive integer of the number of bytes to be passed to |
39 | * the underlying stream |
40 | */ |
41 | public LimitedOutputStream(OutputStream out, int limit) { |
42 | super(out); |
43 | this.limit = limit; |
44 | this.computedBytes = 0; |
45 | } |
46 | |
47 | public void write(byte[] b, int off, int len) throws IOException { |
48 | if (len > limit - computedBytes) { |
49 | len = limit - computedBytes; |
50 | } |
51 | if (len > 0) { |
52 | out.write(b, off, len); |
53 | computedBytes += len; |
54 | } |
55 | } |
56 | |
57 | public void write(int b) throws IOException { |
58 | if (computedBytes < limit) { |
59 | out.write(b); |
60 | computedBytes++; |
61 | } |
62 | } |
63 | |
64 | /** |
65 | * @return the number of bytes passed to the underlying stream |
66 | */ |
67 | public int getComputedBytes() { |
68 | return computedBytes; |
69 | } |
70 | |
71 | /** |
72 | * @return true if the limit has been reached and no data is being passed to |
73 | * the underlying stream. |
74 | */ |
75 | public boolean isLimited() { |
76 | return computedBytes >= limit; |
77 | } |
78 | } |