API Overview API Index Package Overview Direct link to this page
JDK 1.6
  java.nio.charset. CoderResult View Javadoc
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267

/*
 * @(#)CoderResult.java	1.9 05/11/17
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package java.nio.charset;

import java.lang.ref.WeakReference;
import java.nio.*;
import java.util.Map;
import java.util.HashMap;


/**
 * A description of the result state of a coder.
 *
 * <p> A charset coder, that is, either a decoder or an encoder, consumes bytes
 * (or characters) from an input buffer, translates them, and writes the
 * resulting characters (or bytes) to an output buffer.  A coding process
 * terminates for one of four categories of reasons, which are described by
 * instances of this class:
 *
 * <ul>
 *
 *   <li><p> <i>Underflow</i> is reported when there is no more input to be
 *   processed, or there is insufficient input and additional input is
 *   required.  This condition is represented by the unique result object
 *   {@link #UNDERFLOW}, whose {@link #isUnderflow() isUnderflow} method
 *   returns <tt>true</tt>.  </p></li>
 *
 *   <li><p> <i>Overflow</i> is reported when there is insufficient room
 *   remaining in the output buffer.  This condition is represented by the
 *   unique result object {@link #OVERFLOW}, whose {@link #isOverflow()
 *   isOverflow} method returns <tt>true</tt>.  </p></li>
 *
 *   <li><p> A <i>malformed-input error</i> is reported when a sequence of
 *   input units is not well-formed.  Such errors are described by instances of
 *   this class whose {@link #isMalformed() isMalformed} method returns
 *   <tt>true</tt> and whose {@link #length() length} method returns the length
 *   of the malformed sequence.  There is one unique instance of this class for
 *   all malformed-input errors of a given length.  </p></li>
 *
 *   <li><p> An <i>unmappable-character error</i> is reported when a sequence
 *   of input units denotes a character that cannot be represented in the
 *   output charset.  Such errors are described by instances of this class
 *   whose {@link #isUnmappable() isUnmappable} method returns <tt>true</tt> and
 *   whose {@link #length() length} method returns the length of the input
 *   sequence denoting the unmappable character.  There is one unique instance
 *   of this class for all unmappable-character errors of a given length.
 *   </p></li>
 *
 * </ul>
 *
 * For convenience, the {@link #isError() isError} method returns <tt>true</tt>
 * for result objects that describe malformed-input and unmappable-character
 * errors but <tt>false</tt> for those that describe underflow or overflow
 * conditions.  </p>
 *
 *
 * @author Mark Reinhold
 * @author JSR-51 Expert Group
 * @version 1.9, 05/11/17
 * @since 1.4
 */

public class CoderResult {

    private static final int CR_UNDERFLOW  = 0;
    private static final int CR_OVERFLOW   = 1;
    private static final int CR_ERROR_MIN  = 2;
    private static final int CR_MALFORMED  = 2;
    private static final int CR_UNMAPPABLE = 3;

    private static final String[] names
	= { "UNDERFLOW", "OVERFLOW", "MALFORMED", "UNMAPPABLE" };

    private final int type;
    private final int length;

    private CoderResult(int type, int length) {
	this.type = type;
	this.length = length;
    }

    /**
     * Returns a string describing this coder result.
     *
     * @return  A descriptive string
     */
    public String toString() {
	String nm = names[type];
	return isError() ? nm + "[" + length + "]" : nm;
    }

    /**
     * Tells whether or not this object describes an underflow condition.  </p>
     *
     * @return  <tt>true</tt> if, and only if, this object denotes underflow
     */
    public boolean isUnderflow() {
	return (type == CR_UNDERFLOW);
    }

    /**
     * Tells whether or not this object describes an overflow condition.  </p>
     *
     * @return  <tt>true</tt> if, and only if, this object denotes overflow
     */
    public boolean isOverflow() {
	return (type == CR_OVERFLOW);
    }

    /**
     * Tells whether or not this object describes an error condition.  </p>
     *
     * @return  <tt>true</tt> if, and only if, this object denotes either a
     *          malformed-input error or an unmappable-character error
     */
    public boolean isError() {
	return (type >= CR_ERROR_MIN);
    }

    /**
     * Tells whether or not this object describes a malformed-input error.
     * </p>
     *
     * @return  <tt>true</tt> if, and only if, this object denotes a
     *          malformed-input error
     */
    public boolean isMalformed() {
	return (type == CR_MALFORMED);
    }

    /**
     * Tells whether or not this object describes an unmappable-character
     * error.  </p>
     *
     * @return  <tt>true</tt> if, and only if, this object denotes an
     *          unmappable-character error
     */
    public boolean isUnmappable() {
	return (type == CR_UNMAPPABLE);
    }

    /**
     * Returns the length of the erroneous input described by this
     * object&nbsp;&nbsp;<i>(optional operation)</i>.  </p>
     *
     * @return  The length of the erroneous input, a positive integer
     *
     * @throws  UnsupportedOperationException
     *          If this object does not describe an error condition, that is,
     *          if the {@link #isError() isError} does not return <tt>true</tt>
     */
    public int length() {
	if (!isError())
	    throw new UnsupportedOperationException();
	return length;
    }

    /**
     * Result object indicating underflow, meaning that either the input buffer
     * has been completely consumed or, if the input buffer is not yet empty,
     * that additional input is required.  </p>
     */
    public static final CoderResult UNDERFLOW
	= new CoderResult(CR_UNDERFLOW, 0);

    /**
     * Result object indicating overflow, meaning that there is insufficient
     * room in the output buffer.  </p>
     */
    public static final CoderResult OVERFLOW
	= new CoderResult(CR_OVERFLOW, 0);

    private static abstract class Cache {

	private Map cache = null;

	protected abstract CoderResult create(int len);

	private synchronized CoderResult get(int len) {
	    if (len <= 0)
		throw new IllegalArgumentException("Non-positive length");
	    Integer k = new Integer(len);
	    WeakReference w;
	    CoderResult e = null;
	    if (cache == null) {
		cache = new HashMap();
	    } else if ((w = (WeakReference)cache.get(k)) != null) {
		e = (CoderResult)w.get();
	    }
	    if (e == null) {
		e = create(len);
		cache.put(k, new WeakReference(e));
	    }
	    return e;
	}

    }

    private static Cache malformedCache
	= new Cache() {
		public CoderResult create(int len) {
		    return new CoderResult(CR_MALFORMED, len);
		}};

    /**
     * Static factory method that returns the unique object describing a
     * malformed-input error of the given length.  </p>
     *
     * @return  The requested coder-result object
     */
    public static CoderResult malformedForLength(int length) {
	return malformedCache.get(length);
    }

    private static Cache unmappableCache
	= new Cache() {
		public CoderResult create(int len) {
		    return new CoderResult(CR_UNMAPPABLE, len);
		}};

    /**
     * Static factory method that returns the unique result object describing
     * an unmappable-character error of the given length.  </p>
     *
     * @return  The requested coder-result object
     */
    public static CoderResult unmappableForLength(int length) {
	return unmappableCache.get(length);
    }

    /**
     * Throws an exception appropriate to the result described by this object.
     * </p>
     *
     * @throws  BufferUnderflowException
     *          If this object is {@link #UNDERFLOW}
     *
     * @throws  BufferOverflowException
     *          If this object is {@link #OVERFLOW}
     *
     * @throws  MalformedInputException
     *          If this object represents a malformed-input error; the
     *          exception's length value will be that of this object
     *
     * @throws  UnmappableCharacterException
     *          If this object represents an unmappable-character error; the
     *          exceptions length value will be that of this object
     */
    public void throwException()
	throws CharacterCodingException
    {
	switch (type) {
	case CR_UNDERFLOW:   throw new BufferUnderflowException();
	case CR_OVERFLOW:    throw new BufferOverflowException();
	case CR_MALFORMED:   throw new MalformedInputException(length);
	case CR_UNMAPPABLE:  throw new UnmappableCharacterException(length);
	default:
	    assert false;
	}
    }

}

Generated By: JavaOnTracks Doclet 0.1.4     ©Thibaut Colar