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 
17 package com.google.common.io;
18 
19 import java.io.Closeable;
20 import java.io.Flushable;
21 import java.io.IOException;
22 import java.io.Writer;
23 
24 /**
25  * Unit test for {@link AppendableWriter}.
26  *
27  * @author Alan Green
28  */
29 public class AppendableWriterTest extends IoTestCase {
30 
31   /** Helper class for testing behavior with Flushable and Closeable targets. */
32   private static class SpyAppendable implements Appendable, Flushable, Closeable {
33     boolean flushed;
34     boolean closed;
35     StringBuilder result = new StringBuilder();
36 
37     @Override
append(CharSequence csq)38     public Appendable append(CharSequence csq) {
39       result.append(csq);
40       return this;
41     }
42 
43     @Override
append(char c)44     public Appendable append(char c) {
45       result.append(c);
46       return this;
47     }
48 
49     @Override
append(CharSequence csq, int start, int end)50     public Appendable append(CharSequence csq, int start, int end) {
51       result.append(csq, start, end);
52       return this;
53     }
54 
55     @Override
flush()56     public void flush() {
57       flushed = true;
58     }
59 
60     @Override
close()61     public void close() {
62       closed = true;
63     }
64   }
65 
testWriteMethods()66   public void testWriteMethods() throws IOException {
67     StringBuilder builder = new StringBuilder();
68     Writer writer = new AppendableWriter(builder);
69 
70     writer.write("Hello".toCharArray());
71     writer.write(',');
72     writer.write(0xBEEF0020); // only lower 16 bits are important
73     writer.write("Wo");
74     writer.write("Whirled".toCharArray(), 3, 2);
75     writer.write("Mad! Mad, I say", 2, 2);
76 
77     assertEquals("Hello, World!", builder.toString());
78   }
79 
testAppendMethods()80   public void testAppendMethods() throws IOException {
81     StringBuilder builder = new StringBuilder();
82     Writer writer = new AppendableWriter(builder);
83 
84     writer.append("Hello,");
85     writer.append(' ');
86     writer.append("The World Wide Web", 4, 9);
87     writer.append("!");
88 
89     assertEquals("Hello, World!", builder.toString());
90   }
91 
testCloseFlush()92   public void testCloseFlush() throws IOException {
93     SpyAppendable spy = new SpyAppendable();
94     Writer writer = new AppendableWriter(spy);
95 
96     writer.write("Hello");
97     assertFalse(spy.flushed);
98     assertFalse(spy.closed);
99 
100     writer.flush();
101     assertTrue(spy.flushed);
102     assertFalse(spy.closed);
103 
104     writer.close();
105     assertTrue(spy.flushed);
106     assertTrue(spy.closed);
107   }
108 
testCloseIsFinal()109   public void testCloseIsFinal() throws IOException {
110     StringBuilder builder = new StringBuilder();
111     Writer writer = new AppendableWriter(builder);
112 
113     writer.write("Hi");
114     writer.close();
115 
116     try {
117       writer.write(" Greg");
118       fail("Should have thrown IOException due to writer already closed");
119     } catch (IOException expected) {
120     }
121 
122     try {
123       writer.flush();
124       fail("Should have thrown IOException due to writer already closed");
125     } catch (IOException expected) {
126     }
127 
128     // close()ing already closed writer is allowed
129     writer.close();
130   }
131 }
132