001/* CoderResult.java -- 002 Copyright (C) 2002, 2004 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038package java.nio.charset; 039 040import java.lang.ref.WeakReference; 041import java.nio.BufferOverflowException; 042import java.nio.BufferUnderflowException; 043import java.util.HashMap; 044 045/** 046 * @author Jesse Rosenstock 047 * @since 1.4 048 */ 049public class CoderResult 050{ 051 private static final int TYPE_MALFORMED = 0; 052 private static final int TYPE_OVERFLOW = 1; 053 private static final int TYPE_UNDERFLOW = 2; 054 private static final int TYPE_UNMAPPABLE = 3; 055 056 public static final CoderResult OVERFLOW 057 = new CoderResult (TYPE_OVERFLOW, 0); 058 public static final CoderResult UNDERFLOW 059 = new CoderResult (TYPE_UNDERFLOW, 0); 060 061 private static final String[] names 062 = { "MALFORMED", "OVERFLOW", "UNDERFLOW", "UNMAPPABLE" }; 063 064 private static final Cache malformedCache 065 = new Cache () 066 { 067 protected CoderResult make (int length) 068 { 069 return new CoderResult (TYPE_MALFORMED, length); 070 } 071 }; 072 073 private static final Cache unmappableCache 074 = new Cache () 075 { 076 protected CoderResult make (int length) 077 { 078 return new CoderResult (TYPE_UNMAPPABLE, length); 079 } 080 }; 081 082 private final int type; 083 private final int length; 084 085 // Package-private to avoid a trampoline constructor. 086 CoderResult (int type, int length) 087 { 088 this.type = type; 089 this.length = length; 090 } 091 092 public boolean isError () 093 { 094 return length > 0; 095 } 096 097 public boolean isMalformed () 098 { 099 return type == TYPE_MALFORMED; 100 } 101 102 public boolean isOverflow () 103 { 104 return type == TYPE_OVERFLOW; 105 } 106 107 public boolean isUnderflow () 108 { 109 return type == TYPE_UNDERFLOW; 110 } 111 112 public boolean isUnmappable () 113 { 114 return type == TYPE_UNMAPPABLE; 115 } 116 117 public int length () 118 { 119 if (length <= 0) 120 throw new UnsupportedOperationException (); 121 else 122 return length; 123 } 124 125 public static CoderResult malformedForLength (int length) 126 { 127 return malformedCache.get (length); 128 } 129 130 public void throwException () 131 throws CharacterCodingException 132 { 133 switch (type) 134 { 135 case TYPE_MALFORMED: 136 throw new MalformedInputException (length); 137 case TYPE_OVERFLOW: 138 throw new BufferOverflowException (); 139 case TYPE_UNDERFLOW: 140 throw new BufferUnderflowException (); 141 case TYPE_UNMAPPABLE: 142 throw new UnmappableCharacterException (length); 143 } 144 } 145 146 public String toString () 147 { 148 String name = names[type]; 149 return (length > 0) ? name + '[' + length + ']' : name; 150 } 151 152 public static CoderResult unmappableForLength (int length) 153 { 154 return unmappableCache.get (length); 155 } 156 157 private abstract static class Cache 158 { 159 private final HashMap cache; 160 161 // Package-private to avoid a trampoline constructor. 162 Cache () 163 { 164 cache = new HashMap (); 165 } 166 167 // Package-private to avoid a trampoline. 168 synchronized CoderResult get (int length) 169 { 170 if (length <= 0) 171 throw new IllegalArgumentException ("Non-positive length"); 172 173 Integer len = Integer.valueOf (length); 174 CoderResult cr = null; 175 Object o; 176 if ((o = cache.get (len)) != null) 177 cr = (CoderResult) ((WeakReference) o).get (); 178 if (cr == null) 179 { 180 cr = make (length); 181 cache.put (len, new WeakReference (cr)); 182 } 183 184 return cr; 185 } 186 187 protected abstract CoderResult make (int length); 188 } 189}