1 /*
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3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5  * This code is free software; you can redistribute it and/or modify it
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7  * published by the Free Software Foundation.
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9  * This code is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * version 2 for more details (a copy is included in the LICENSE file that
13  * accompanied this code).
14  *
15  * You should have received a copy of the GNU General Public License version
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23 
24 /**
25  * @test
26  * @bug 5030063
27  * @summary Basic tests for flush().
28  */
29 
30 import java.io.Closeable;
31 import java.io.Flushable;
32 import java.util.Formatter;
33 import java.util.FormatterClosedException;
34 
35 public class Flush {
36 
37     private static class ExpectedException extends RuntimeException {}
38 
39     private static class F implements Appendable, Closeable, Flushable {
append(CharSequence csq)40         public Appendable append(CharSequence csq) { return null; }
append(char c)41         public Appendable append(char c) { return null; }
append(CharSequence csq, int s, int e)42         public Appendable append(CharSequence csq, int s, int e) {
43             return null;
44         }
close()45         public void close() {}
46 
flush()47         public void flush() {
48             throw new ExpectedException();
49         }
50     }
51 
52     private static class NF implements Appendable, Closeable {
append(CharSequence csq)53         public Appendable append(CharSequence csq) { return null; }
append(char c)54         public Appendable append(char c) { return null; }
append(CharSequence csq, int s, int e)55         public Appendable append(CharSequence csq, int s, int e) {
56             return null;
57         }
close()58         public void close() {}
59 
60         // method coincidentally called flush()
flush()61         public void flush() {
62             throw new RuntimeException("NF.flush should not be called");
63         }
64     }
65 
test(Formatter f)66     private static void test(Formatter f) {
67         if (f.out() instanceof F) {
68             // F.flush() called since F implements Flushable
69             try {
70                 f.flush();
71                 throw new RuntimeException("F.flush not called");
72             } catch (ExpectedException x) {
73                 System.out.println("  F.flush called");
74             }
75         } else {
76             // NF.flush() not called since NF does not implement Flushable
77             f.flush();
78         }
79 
80         // Formatter is a Flushable
81         if (!(f instanceof Flushable))
82             throw new RuntimeException("Formatter is not a Flushable");
83 
84         // flush() after close() throws a FormatterClosedException
85         f.close();
86         try {
87             f.flush();
88             throw new RuntimeException("FormatterClosedException not thrown");
89         } catch (FormatterClosedException x) {
90             System.out.println("  FormatterClosedException thrown");
91         }
92     }
93 
main(String [] args)94     public static void main(String [] args) {
95         System.out.println("testing Flushable");
96         test(new Formatter(new F()));
97         System.out.println("testing non-Flushable");
98         test(new Formatter(new NF()));
99     }
100 }
101