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54 package org.logicalcobwebs.cglib.core;
55
56 import java.io.*;
57 import java.lang.reflect.*;
58 import java.util.*;
59 import org.logicalcobwebs.asm.ClassReader;
60 import org.logicalcobwebs.asm.ClassVisitor;
61 import org.logicalcobwebs.asm.ClassWriter;
62 import org.logicalcobwebs.asm.Type;
63
64
70 abstract public class AbstractClassGenerator
71 implements ClassGenerator
72 {
73 private static final Object  NAME_KEY = new Object ();
74
75 private GeneratorStrategy strategy = DefaultGeneratorStrategy.INSTANCE;
76 private NamingPolicy namingPolicy;
77 private Source source;
78 private ClassLoader classLoader;
79 private String namePrefix;
80 private Object key;
81 private boolean useCache = true;
82
83 protected static class Source {
84 String name;
85 Map cache = new WeakHashMap();
86 public Source(String name) {
87 this.name = name;
88 }
89 }
90
91 protected AbstractClassGenerator(Source source) {
92 this.source = source;
93 }
94
95 protected void setNamePrefix(String namePrefix) {
96 this.namePrefix = namePrefix;
97 }
98
99 final protected String getClassName() {
100 return getClassName(getClassLoader());
101 }
102
103 private String getClassName(ClassLoader loader) {
104 NamingPolicy np = (namingPolicy != null) ? namingPolicy : DefaultNamingPolicy.INSTANCE;
105 final Set nameCache = getClassNameCache(loader);
106 return np.getClassName(namePrefix, source.name, key, new Predicate() {
107 public boolean evaluate(Object arg) {
108 return nameCache.contains(arg);
109 }
110 });
111 }
112
113 private Set getClassNameCache(ClassLoader loader) {
114 return (Set)((Map)source.cache.get(loader)).get(NAME_KEY);
115 }
116
117
126 public void setClassLoader(ClassLoader classLoader) {
127 this.classLoader = classLoader;
128 }
129
130
135 public void setNamingPolicy(NamingPolicy namingPolicy) {
136 this.namingPolicy = namingPolicy;
137 }
138
139
143 public void setUseCache(boolean useCache) {
144 this.useCache = useCache;
145 }
146
147
151 public void setStrategy(GeneratorStrategy strategy) {
152 this.strategy = strategy;
153 }
154
155 protected ClassLoader getClassLoader() {
157 ClassLoader t = classLoader;
158 if (t == null) {
159 t = getDefaultClassLoader();
160 }
161 if (t == null) {
162 t = getClass().getClassLoader();
163 }
164 if (t == null) {
165 throw new IllegalStateException ("Cannot determine classloader");
166 }
167 return t;
168 }
169
170 abstract protected ClassLoader getDefaultClassLoader();
171
172 protected Object create(Object key) {
173 try {
174 Object instance = null;
175 synchronized (source) {
176 ClassLoader loader = getClassLoader();
177 Map cache2 = null;
178 if (useCache) {
179 cache2 = (Map)source.cache.get(loader);
180 if (cache2 != null) {
181 instance = cache2.get(key);
182 } else {
183 cache2 = new HashMap();
184 cache2.put(NAME_KEY, new HashSet());
185 source.cache.put(loader, cache2);
186 }
187 }
188 if (instance == null) {
189 this.key = key;
190 byte[] b = strategy.generate(this);
191 String className = ClassNameReader.getClassName(new ClassReader(b));
192 getClassNameCache(loader).add(className);
193 instance = firstInstance(ReflectUtils.defineClass(className, b, loader));
194 if (useCache) {
195 cache2.put(key, instance);
196 }
197 return instance;
198 }
199 }
200 return nextInstance(instance);
201 } catch (RuntimeException e) {
202 throw e;
203 } catch (Error e) {
204 throw e;
205 } catch (Exception e) {
206 throw new CodeGenerationException(e);
207 }
208 }
209
210 abstract protected Object firstInstance(Class type) throws Exception ;
211 abstract protected Object nextInstance(Object instance) throws Exception ;
212 }
213 |
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