1 /*
2 * Copyright 2007 Kasper B. Graversen
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.supercsv.util;
17
18 import java.lang.reflect.Method;
19
20 import org.supercsv.exception.SuperCsvReflectionException;
21
22 /**
23 * This class cache's method lookups. Hence first time it introspects the instance's class, while subsequent method
24 * lookups are super fast.
25 */
26 public class MethodCache {
27
28 /**
29 * A cache of setter methods. The three keys are the class the setter is being invoked on, the parameter type of the
30 * setter, and the variable name. The value is the setter method.
31 */
32 private final ThreeDHashMap<Class<?>, Class<?>, String, Method> setMethodsCache = new ThreeDHashMap<Class<?>, Class<?>, String, Method>();
33
34 /**
35 * A cache of getter methods. The two keys are the name of the class the getter is being invoked on, and the
36 * variable name. The value is the getter method.
37 */
38 private final TwoDHashMap<String, String, Method> getCache = new TwoDHashMap<String, String, Method>();
39
40 /**
41 * Returns the getter method for field on an object.
42 *
43 * @param object
44 * the object
45 * @param fieldName
46 * the field name
47 * @return the getter associated with the field on the object
48 * @throws NullPointerException
49 * if object or fieldName is null
50 * @throws SuperCsvReflectionException
51 * if the getter doesn't exist or is not visible
52 */
53 public Method getGetMethod(final Object object, final String fieldName) {
54 if( object == null ) {
55 throw new NullPointerException("object should not be null");
56 } else if( fieldName == null ) {
57 throw new NullPointerException("fieldName should not be null");
58 }
59
60 Method method = getCache.get(object.getClass().getName(), fieldName);
61 if( method == null ) {
62 method = ReflectionUtils.findGetter(object, fieldName);
63 getCache.set(object.getClass().getName(), fieldName, method);
64 }
65 return method;
66 }
67
68 /**
69 * Returns the setter method for the field on an object.
70 *
71 * @param object
72 * the object
73 * @param fieldName
74 * the field name
75 * @param argumentType
76 * the type to be passed to the setter
77 * @param <T>
78 * the object type
79 * @return the setter method associated with the field on the object
80 * @throws NullPointerException
81 * if object, fieldName or fieldType is null
82 * @throws SuperCsvReflectionException
83 * if the setter doesn't exist or is not visible
84 */
85 public <T> Method getSetMethod(final Object object, final String fieldName, final Class<?> argumentType) {
86 if( object == null ) {
87 throw new NullPointerException("object should not be null");
88 } else if( fieldName == null ) {
89 throw new NullPointerException("fieldName should not be null");
90 } else if( argumentType == null ) {
91 throw new NullPointerException("argumentType should not be null");
92 }
93
94 Method method = setMethodsCache.get(object.getClass(), argumentType, fieldName);
95 if( method == null ) {
96 method = ReflectionUtils.findSetter(object, fieldName, argumentType);
97 setMethodsCache.set(object.getClass(), argumentType, fieldName, method);
98 }
99 return method;
100 }
101
102 }