LimitInputStreamTest.java revision 1d580d0f6ee4f21eb309ba7b509d2c6d671c4044 
1/*
2 * Copyright (C) 2007 The Guava Authors
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
17package com.google.common.io;
18
19import java.io.ByteArrayInputStream;
20import java.io.IOException;
21import java.io.InputStream;
22
23/**
24 * @author Charles Fry
25 */
26public class LimitInputStreamTest extends IoTestCase {
27
28  public void testLimit() throws Exception {
29    byte[] big = newPreFilledByteArray(5);
30    InputStream bin = new ByteArrayInputStream(big);
31    InputStream lin = new LimitInputStream(bin, 2);
32
33    // also test available
34    lin.mark(2);
35    assertEquals(2, lin.available());
36    int read = lin.read();
37    assertEquals(big[0], read);
38    assertEquals(1, lin.available());
39    read = lin.read();
40    assertEquals(big[1], read);
41    assertEquals(0, lin.available());
42    read = lin.read();
43    assertEquals(-1, read);
44
45    lin.reset();
46    byte[] small = new byte[5];
47    read = lin.read(small);
48    assertEquals(2, read);
49    assertEquals(big[0], small[0]);
50    assertEquals(big[1], small[1]);
51
52    lin.reset();
53    read = lin.read(small, 2, 3);
54    assertEquals(2, read);
55    assertEquals(big[0], small[2]);
56    assertEquals(big[1], small[3]);
57  }
58
59  public void testMark() throws Exception {
60    byte[] big = newPreFilledByteArray(5);
61    InputStream bin = new ByteArrayInputStream(big);
62    InputStream lin = new LimitInputStream(bin, 2);
63
64    int read = lin.read();
65    assertEquals(big[0], read);
66    lin.mark(2);
67
68    read = lin.read();
69    assertEquals(big[1], read);
70    read = lin.read();
71    assertEquals(-1, read);
72
73    lin.reset();
74    read = lin.read();
75    assertEquals(big[1], read);
76    read = lin.read();
77    assertEquals(-1, read);
78  }
79
80  public void testSkip() throws Exception {
81    byte[] big = newPreFilledByteArray(5);
82    InputStream bin = new ByteArrayInputStream(big);
83    InputStream lin = new LimitInputStream(bin, 2);
84
85    // also test available
86    lin.mark(2);
87    assertEquals(2, lin.available());
88    lin.skip(1);
89    assertEquals(1, lin.available());
90
91    lin.reset();
92    assertEquals(2, lin.available());
93    lin.skip(3);
94    assertEquals(0, lin.available());
95  }
96
97
98  public void testMarkNotSet() {
99    byte[] big = newPreFilledByteArray(5);
100    InputStream bin = new ByteArrayInputStream(big);
101    InputStream lin = new LimitInputStream(bin, 2);
102
103    try {
104      lin.reset();
105      fail();
106    } catch (IOException expected) {
107      assertEquals("Mark not set", expected.getMessage());
108    }
109  }
110
111  public void testMarkNotSupported() {
112    InputStream lin = new LimitInputStream(new UnmarkableInputStream(), 2);
113
114    try {
115      lin.reset();
116      fail();
117    } catch (IOException expected) {
118      assertEquals("Mark not supported", expected.getMessage());
119    }
120  }
121
122  private static class UnmarkableInputStream extends InputStream {
123    @Override
124    public int read() throws IOException {
125      return 0;
126    }
127
128    @Override
129    public boolean markSupported() {
130      return false;
131    }
132  }
133}
134