Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
AbstractConversionFactory |
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| 1.5454545454545454;1.545 | ||||
AbstractConversionFactory$FactoryConversion |
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| 1.5454545454545454;1.545 |
1 | /* | |
2 | * Copyright 2004 The Apache Software Foundation | |
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 | package org.apache.commons.convert.conversion; | |
17 | ||
18 | import org.apache.commons.convert.Conversion; | |
19 | import org.apache.commons.convert.ConversionFactory; | |
20 | import org.apache.commons.convert.Converter; | |
21 | ||
22 | /** | |
23 | * Abstract base class for creating conversion factories. | |
24 | * <p> | |
25 | * This class is especially suited for creating factories as it minimises the effort | |
26 | * required in the subclass. | |
27 | * <p> | |
28 | * To implement a conversion from a class and all of it subclasses, simply extend | |
29 | * this class and implement the {@link #convertValue(Object, Converter)} method. | |
30 | * | |
31 | * @author Stephen Colebourne | |
32 | * @author Oliver Heger | |
33 | * @version $Id: AbstractConversionFactory.java 155441 2005-02-26 13:19:22Z dirkv $ | |
34 | * @since 1.0 | |
35 | */ | |
36 | public abstract class AbstractConversionFactory implements ConversionFactory { | |
37 | ||
38 | /** Useful constant for subclass constructors */ | |
39 | 0 | protected static final Class STRING_CLASS = String.class; |
40 | ||
41 | /** The base type to convert from */ | |
42 | private final Class baseFromType; | |
43 | /** The type to convert to */ | |
44 | private final Class toType; | |
45 | ||
46 | /** | |
47 | * Restricted constructor. | |
48 | * | |
49 | * @param baseFromType the base of the class hierarchy to convert from | |
50 | * @param toType the type to convert to | |
51 | */ | |
52 | protected AbstractConversionFactory(Class baseFromType, Class toType) { | |
53 | 0 | super(); |
54 | 0 | this.baseFromType = baseFromType; |
55 | 0 | this.toType = toType; |
56 | 0 | } |
57 | ||
58 | //----------------------------------------------------------------------- | |
59 | /** | |
60 | * Checks if this factory matches the request conversion. | |
61 | * <p> | |
62 | * This implementation returns {@link #getMatchPercent()} if the specified | |
63 | * <code>fromType</code> is the same as, or a subclass of, the stored | |
64 | * <code>baseFromType</code> and the specified <code>toType</code> matches | |
65 | * the stored <code>toType</code>. | |
66 | * | |
67 | * @param value the value to be converted, read only, may be null | |
68 | * @param fromType the type to convert from, may be null | |
69 | * @param toType the type to convert to, may be null | |
70 | * @return 60 if baseFromType or subclass matches fromType and toType matches | |
71 | */ | |
72 | public int getMatchPercent(Object value, Class fromType, Class toType) { | |
73 | 0 | if (toType == getToType() && getBaseFromType().isAssignableFrom(fromType)) { |
74 | 0 | return getMatchPercent(); |
75 | } | |
76 | 0 | return 0; |
77 | } | |
78 | ||
79 | /** | |
80 | * Gets the percentage to return if a match occurs. | |
81 | * <p> | |
82 | * This implementation returns <code>60</code>. | |
83 | * Subclasses may wish to override and return a different value. | |
84 | * | |
85 | * @return 60 | |
86 | */ | |
87 | protected int getMatchPercent() { | |
88 | 0 | return 60; |
89 | } | |
90 | ||
91 | /** | |
92 | * Create a new conversion object for the specified from and to types. | |
93 | * <p> | |
94 | * This implementation returns a <code>Conversion</code> instance that | |
95 | * refers back to this class for its implementation of the actual conversion | |
96 | * via {@link #convertValue(Object, Converter)}. | |
97 | * | |
98 | * @param value the value to be converted, read only, may be null | |
99 | * @param fromType the type to convert from, may be null | |
100 | * @param toType the type to convert to, may be null | |
101 | * @return a Conversion object for repeatedly performing conversions | |
102 | */ | |
103 | public Conversion getInstance(Object value, Class fromType, Class toType) { | |
104 | 0 | return new FactoryConversion(fromType, toType, this); |
105 | } | |
106 | ||
107 | /** | |
108 | * Convert the non-null value to another type. | |
109 | * <p> | |
110 | * This method is implemented by subclases to perform the actual conversion. | |
111 | * | |
112 | * @param value the input value to be converted, pre-checked to not be null | |
113 | * @param converter the converter being used, not null | |
114 | * @return the converted value | |
115 | * @throws Exception if conversion fails, use ConversionException if creating | |
116 | * a new exception, otherwise just allow exceptions to be thrown | |
117 | */ | |
118 | protected abstract Object convertValue(Object value, Converter converter) throws Exception; | |
119 | ||
120 | //----------------------------------------------------------------------- | |
121 | /** | |
122 | * The base type to convert from. | |
123 | * This type and its subclasses will be matched by this factory. | |
124 | * | |
125 | * @return the Class object representing the class to convert to | |
126 | */ | |
127 | public Class getBaseFromType() { | |
128 | 0 | return baseFromType; |
129 | } | |
130 | ||
131 | /** | |
132 | * The type to convert to. | |
133 | * | |
134 | * @return the Class object representing the class to convert from | |
135 | */ | |
136 | public Class getToType() { | |
137 | 0 | return toType; |
138 | } | |
139 | ||
140 | //----------------------------------------------------------------------- | |
141 | /** | |
142 | * Gets a suitable debugging string. | |
143 | * | |
144 | * @return a debugging string | |
145 | */ | |
146 | public String toString() { | |
147 | 0 | String from = convertClassToName(getBaseFromType()); |
148 | 0 | String to = convertClassToName(getToType()); |
149 | 0 | return "ConversionFactory[" + from + "->" + to + "]"; |
150 | } | |
151 | ||
152 | /** | |
153 | * Converts a class to a string name for debugging. | |
154 | * | |
155 | * @param cls the class to convert | |
156 | * @return the class name | |
157 | */ | |
158 | private String convertClassToName(Class cls) { | |
159 | 0 | if (cls == null) { |
160 | 0 | return "null"; |
161 | } | |
162 | 0 | String str = cls.getName(); |
163 | 0 | int pos = str.lastIndexOf('.'); |
164 | 0 | if (str.substring(0, pos).equals("java.lang")) { |
165 | 0 | str = str.substring(pos + 1); |
166 | } | |
167 | 0 | if (str.substring(0, pos).equals("java.util")) { |
168 | 0 | str = str.substring(pos + 1); |
169 | } | |
170 | 0 | return str; |
171 | } | |
172 | ||
173 | //----------------------------------------------------------------------- | |
174 | /** | |
175 | * Generic conversion implementation that delegates back to the factory. | |
176 | */ | |
177 | class FactoryConversion extends AbstractConversion { | |
178 | ||
179 | /** The factory instance that has the actual conversion code */ | |
180 | private final AbstractConversionFactory factory; | |
181 | ||
182 | /** | |
183 | * Constructs a Conversion. | |
184 | * | |
185 | * @param fromType the type to convert from | |
186 | * @param toType the type to convert to | |
187 | * @param factory the factory instance that actually performs the conversion | |
188 | */ | |
189 | 0 | FactoryConversion(Class fromType, Class toType, AbstractConversionFactory factory) { |
190 | 0 | super(fromType, toType); |
191 | 0 | this.factory = factory; |
192 | 0 | } |
193 | ||
194 | /** | |
195 | * Convert the non-null value to another type. | |
196 | * <p> | |
197 | * This implementation delegates to the factory method | |
198 | * {@link AbstractConversionFactory#convertValue(Object, Converter)}. | |
199 | * | |
200 | * @param value the input value to be converted, pre-checked to not be null | |
201 | * @param converter the converter being used, not null | |
202 | * @return the converted value | |
203 | * @throws Exception if conversion fails, use ConversionException if creating | |
204 | * a new exception, otherwise just allow exceptions to be thrown | |
205 | */ | |
206 | protected Object convertValue(Object value, Converter converter) throws Exception { | |
207 | 0 | return factory.convertValue(value, converter); |
208 | } | |
209 | } | |
210 | ||
211 | } |