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16 package org.apache.ibatis.executor.loader.cglib;
17
18 import java.lang.reflect.Method;
19 import java.util.List;
20 import java.util.Map;
21 import java.util.Set;
22
23 import net.sf.cglib.proxy.Callback;
24 import net.sf.cglib.proxy.Enhancer;
25 import net.sf.cglib.proxy.MethodInterceptor;
26 import net.sf.cglib.proxy.MethodProxy;
27
28 import org.apache.ibatis.executor.loader.AbstractEnhancedDeserializationProxy;
29 import org.apache.ibatis.executor.loader.AbstractSerialStateHolder;
30 import org.apache.ibatis.executor.loader.ProxyFactory;
31 import org.apache.ibatis.executor.loader.ResultLoaderMap;
32 import org.apache.ibatis.executor.loader.WriteReplaceInterface;
33 import org.apache.ibatis.io.Resources;
34 import org.apache.ibatis.logging.Log;
35 import org.apache.ibatis.logging.LogFactory;
36 import org.apache.ibatis.reflection.ExceptionUtil;
37 import org.apache.ibatis.reflection.factory.ObjectFactory;
38 import org.apache.ibatis.reflection.property.PropertyCopier;
39 import org.apache.ibatis.reflection.property.PropertyNamer;
40 import org.apache.ibatis.session.Configuration;
41
42
43
44
45 public class CglibProxyFactory implements ProxyFactory {
46
47 private static final String FINALIZE_METHOD = "finalize";
48 private static final String WRITE_REPLACE_METHOD = "writeReplace";
49
50 public CglibProxyFactory() {
51 try {
52 Resources.classForName("net.sf.cglib.proxy.Enhancer");
53 } catch (Throwable e) {
54 throw new IllegalStateException("Cannot enable lazy loading because CGLIB is not available. Add CGLIB to your classpath.", e);
55 }
56 }
57
58 @Override
59 public Object createProxy(Object target, ResultLoaderMap lazyLoader, Configuration configuration, ObjectFactory objectFactory, List<Class<?>> constructorArgTypes, List<Object> constructorArgs) {
60 return EnhancedResultObjectProxyImpl.createProxy(target, lazyLoader, configuration, objectFactory, constructorArgTypes, constructorArgs);
61 }
62
63 public Object createDeserializationProxy(Object target, Map<String, ResultLoaderMap.LoadPair> unloadedProperties, ObjectFactory objectFactory, List<Class<?>> constructorArgTypes, List<Object> constructorArgs) {
64 return EnhancedDeserializationProxyImpl.createProxy(target, unloadedProperties, objectFactory, constructorArgTypes, constructorArgs);
65 }
66
67 static Object crateProxy(Class<?> type, Callback callback, List<Class<?>> constructorArgTypes, List<Object> constructorArgs) {
68 Enhancer enhancer = new Enhancer();
69 enhancer.setCallback(callback);
70 enhancer.setSuperclass(type);
71 try {
72 type.getDeclaredMethod(WRITE_REPLACE_METHOD);
73
74 if (LogHolder.log.isDebugEnabled()) {
75 LogHolder.log.debug(WRITE_REPLACE_METHOD + " method was found on bean " + type + ", make sure it returns this");
76 }
77 } catch (NoSuchMethodException e) {
78 enhancer.setInterfaces(new Class[]{WriteReplaceInterface.class});
79 } catch (SecurityException e) {
80
81 }
82 Object enhanced;
83 if (constructorArgTypes.isEmpty()) {
84 enhanced = enhancer.create();
85 } else {
86 Class<?>[] typesArray = constructorArgTypes.toArray(new Class[constructorArgTypes.size()]);
87 Object[] valuesArray = constructorArgs.toArray(new Object[constructorArgs.size()]);
88 enhanced = enhancer.create(typesArray, valuesArray);
89 }
90 return enhanced;
91 }
92
93 private static class EnhancedResultObjectProxyImpl implements MethodInterceptor {
94
95 private final Class<?> type;
96 private final ResultLoaderMap lazyLoader;
97 private final boolean aggressive;
98 private final Set<String> lazyLoadTriggerMethods;
99 private final ObjectFactory objectFactory;
100 private final List<Class<?>> constructorArgTypes;
101 private final List<Object> constructorArgs;
102
103 private EnhancedResultObjectProxyImpl(Class<?> type, ResultLoaderMap lazyLoader, Configuration configuration, ObjectFactory objectFactory, List<Class<?>> constructorArgTypes, List<Object> constructorArgs) {
104 this.type = type;
105 this.lazyLoader = lazyLoader;
106 this.aggressive = configuration.isAggressiveLazyLoading();
107 this.lazyLoadTriggerMethods = configuration.getLazyLoadTriggerMethods();
108 this.objectFactory = objectFactory;
109 this.constructorArgTypes = constructorArgTypes;
110 this.constructorArgs = constructorArgs;
111 }
112
113 public static Object createProxy(Object target, ResultLoaderMap lazyLoader, Configuration configuration, ObjectFactory objectFactory, List<Class<?>> constructorArgTypes, List<Object> constructorArgs) {
114 final Class<?> type = target.getClass();
115 EnhancedResultObjectProxyImpl callback = new EnhancedResultObjectProxyImpl(type, lazyLoader, configuration, objectFactory, constructorArgTypes, constructorArgs);
116 Object enhanced = crateProxy(type, callback, constructorArgTypes, constructorArgs);
117 PropertyCopier.copyBeanProperties(type, target, enhanced);
118 return enhanced;
119 }
120
121 @Override
122 public Object intercept(Object enhanced, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
123 final String methodName = method.getName();
124 try {
125 synchronized (lazyLoader) {
126 if (WRITE_REPLACE_METHOD.equals(methodName)) {
127 Object original;
128 if (constructorArgTypes.isEmpty()) {
129 original = objectFactory.create(type);
130 } else {
131 original = objectFactory.create(type, constructorArgTypes, constructorArgs);
132 }
133 PropertyCopier.copyBeanProperties(type, enhanced, original);
134 if (lazyLoader.size() > 0) {
135 return new CglibSerialStateHolder(original, lazyLoader.getProperties(), objectFactory, constructorArgTypes, constructorArgs);
136 } else {
137 return original;
138 }
139 } else {
140 if (lazyLoader.size() > 0 && !FINALIZE_METHOD.equals(methodName)) {
141 if (aggressive || lazyLoadTriggerMethods.contains(methodName)) {
142 lazyLoader.loadAll();
143 } else if (PropertyNamer.isSetter(methodName)) {
144 final String property = PropertyNamer.methodToProperty(methodName);
145 lazyLoader.remove(property);
146 } else if (PropertyNamer.isGetter(methodName)) {
147 final String property = PropertyNamer.methodToProperty(methodName);
148 if (lazyLoader.hasLoader(property)) {
149 lazyLoader.load(property);
150 }
151 }
152 }
153 }
154 }
155 return methodProxy.invokeSuper(enhanced, args);
156 } catch (Throwable t) {
157 throw ExceptionUtil.unwrapThrowable(t);
158 }
159 }
160 }
161
162 private static class EnhancedDeserializationProxyImpl extends AbstractEnhancedDeserializationProxy implements MethodInterceptor {
163
164 private EnhancedDeserializationProxyImpl(Class<?> type, Map<String, ResultLoaderMap.LoadPair> unloadedProperties, ObjectFactory objectFactory,
165 List<Class<?>> constructorArgTypes, List<Object> constructorArgs) {
166 super(type, unloadedProperties, objectFactory, constructorArgTypes, constructorArgs);
167 }
168
169 public static Object createProxy(Object target, Map<String, ResultLoaderMap.LoadPair> unloadedProperties, ObjectFactory objectFactory,
170 List<Class<?>> constructorArgTypes, List<Object> constructorArgs) {
171 final Class<?> type = target.getClass();
172 EnhancedDeserializationProxyImpl callback = new EnhancedDeserializationProxyImpl(type, unloadedProperties, objectFactory, constructorArgTypes, constructorArgs);
173 Object enhanced = crateProxy(type, callback, constructorArgTypes, constructorArgs);
174 PropertyCopier.copyBeanProperties(type, target, enhanced);
175 return enhanced;
176 }
177
178 @Override
179 public Object intercept(Object enhanced, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
180 final Object o = super.invoke(enhanced, method, args);
181 return o instanceof AbstractSerialStateHolder ? o : methodProxy.invokeSuper(o, args);
182 }
183
184 @Override
185 protected AbstractSerialStateHolder newSerialStateHolder(Object userBean, Map<String, ResultLoaderMap.LoadPair> unloadedProperties, ObjectFactory objectFactory,
186 List<Class<?>> constructorArgTypes, List<Object> constructorArgs) {
187 return new CglibSerialStateHolder(userBean, unloadedProperties, objectFactory, constructorArgTypes, constructorArgs);
188 }
189 }
190
191 private static class LogHolder {
192 private static final Log log = LogFactory.getLog(CglibProxyFactory.class);
193 }
194
195 }