|
1
4 package com.tc.aspectwerkz.proxy;
5
6 import com.tc.asm.ClassReader;
7 import com.tc.asm.ClassVisitor;
8 import com.tc.asm.ClassWriter;
9 import com.tc.asm.MethodVisitor;
10 import com.tc.asm.Opcodes;
11 import com.tc.asm.Type;
12
13 import com.tc.aspectwerkz.exception.WrappedRuntimeException;
14 import com.tc.aspectwerkz.transform.TransformationConstants;
15 import com.tc.aspectwerkz.transform.inlining.AsmHelper;
16 import com.tc.aspectwerkz.transform.inlining.AsmNullAdapter;
17
18 import java.io.IOException  ;
19 import java.io.InputStream ;
20 import java.util.HashSet ;
21 import java.util.Set ;
22
23
31 public class ProxyDelegationCompiler implements TransformationConstants {
32
33
41 public static byte[] compileProxyFor(
42 final ClassLoader loader, final Class [] interfaces, final String proxyClassName) {
43 final ClassWriter proxyWriter = AsmHelper.newClassWriter(true);
44
45 final Set methodSignatures = new HashSet ();
46 final String [] interfaceClassNames = new String [interfaces.length];
47 final String [] interfaceSignatures = new String [interfaces.length];
48 for (int i = 0; i < interfaces.length; i++) {
49 interfaceClassNames[i] = interfaces[i].getName().replace('.', '/');
50 interfaceSignatures[i] = 'L' + interfaceClassNames[i] + ';';
51 }
52
53 ProxyCompilerClassVisitor createProxy = new ProxyDelegationCompiler.ProxyCompilerClassVisitor(
55 proxyWriter,
56 proxyClassName.replace('.', '/'),
57 methodSignatures,
58 interfaceClassNames,
59 interfaceSignatures
60 );
61
62 for (int i = 0; i < interfaces.length; i++) {
64 Class anInterface = interfaces[i];
65 final String interfaceClassName = anInterface.getName().replace('.', '/');
66
67 InputStream in = null;
68 final ClassReader classReader;
69 try {
70 if (loader != null) {
71 in = loader.getResourceAsStream(interfaceClassName + ".class");
72 } else {
73 in = ClassLoader.getSystemClassLoader().getResourceAsStream(interfaceClassName + ".class");
74 }
75 classReader = new ClassReader(in);
76 } catch (IOException e) {
77 throw new WrappedRuntimeException("Cannot compile proxy for " + anInterface, e);
78 } finally {
79 try {
80 in.close();
81 } catch (Throwable t) {
82 ;
83 }
84 }
85 classReader.accept(createProxy, true); }
87 return proxyWriter.toByteArray();
88 }
89
90
94 public static class ProxyCompilerClassVisitor extends AsmNullAdapter.NullClassAdapter implements Opcodes, TransformationConstants {
95 final ClassVisitor m_proxyCv;
96 final String m_proxyClassName;
97 final Set m_signatures;
98 private int currentInterfaceIndex = 0;
99 final String [] m_interfaceClassNames;
100 final String [] m_interfaceSignatures;
101
102
110 public ProxyCompilerClassVisitor(final ClassVisitor proxyCv, final String proxyClassName, final Set signatures, final String [] interfaceClassNames, final String [] interfaceSignatures) {
111 m_proxyCv = proxyCv;
112 m_proxyClassName = proxyClassName;
113 m_signatures = signatures;
114 m_interfaceClassNames = interfaceClassNames;
115 m_interfaceSignatures = interfaceSignatures;
116
117 m_proxyCv.visit(
118 AsmHelper.JAVA_VERSION,
119 ACC_PUBLIC + ACC_SYNTHETIC + ACC_SUPER,
120 m_proxyClassName,
121 null,
122 OBJECT_CLASS_NAME,
123 interfaceClassNames
124 );
125
126 for (int i = 0; i < interfaceClassNames.length; i++) {
128 m_interfaceSignatures[i] = 'L' + interfaceClassNames[i] + ';';
129 m_proxyCv.visitField(
130 ACC_PRIVATE + ACC_SYNTHETIC + ACC_FINAL,
131 "DELEGATE_" + i,
132 m_interfaceSignatures[i],
133 null,
134 null
135 );
136 }
137
138 StringBuffer ctorDesc = new StringBuffer ("(");
140 for (int i = 0; i < interfaceClassNames.length; i++) {
141 ctorDesc.append(m_interfaceSignatures[i]);
142 }
143 ctorDesc.append(")V");
144 MethodVisitor init = m_proxyCv.visitMethod(
145 ACC_PUBLIC + ACC_SYNTHETIC,
146 INIT_METHOD_NAME,
147 ctorDesc.toString(),
148 null,
149 null
150 );
151 init.visitVarInsn(ALOAD, 0);
152 init.visitMethodInsn(INVOKESPECIAL, OBJECT_CLASS_NAME, INIT_METHOD_NAME, NO_PARAM_RETURN_VOID_SIGNATURE);
153 for (int i = 0; i < interfaceClassNames.length; i++) {
154 init.visitVarInsn(ALOAD, 0);
155 init.visitVarInsn(ALOAD, 1 + i);
156 init.visitFieldInsn(PUTFIELD, m_proxyClassName, "DELEGATE_" + i, m_interfaceSignatures[i]);
157 }
158 init.visitInsn(RETURN);
159 init.visitMaxs(0, 0);
160 }
161
162
172 public MethodVisitor visitMethod(int access, String name, String desc, String signature, String [] exceptions) {
173 if (m_signatures.contains(name + desc)) {
174 return super.visitMethod(access, name, desc, signature, exceptions);
175 }
176 m_signatures.add(name + desc);
177
178 MethodVisitor cv = m_proxyCv.visitMethod(
179 access & ~ACC_ABSTRACT,
180 name,
181 desc,
182 signature,
183 exceptions
184 );
185
186 cv.visitVarInsn(ALOAD, 0);
187 cv.visitFieldInsn(
188 GETFIELD,
189 m_proxyClassName,
190 "DELEGATE_" + currentInterfaceIndex,
191 m_interfaceSignatures[currentInterfaceIndex]
192 );
193 AsmHelper.loadArgumentTypes(cv, Type.getArgumentTypes(desc), false);
194 cv.visitMethodInsn(
195 INVOKEINTERFACE,
196 m_interfaceClassNames[currentInterfaceIndex],
197 name,
198 desc
199 );
200 AsmHelper.addReturnStatement(cv, Type.getReturnType(desc));
201 cv.visitMaxs(0, 0);
202
203 return cv;
206 }
207
208
211 public void visitEnd() {
212 currentInterfaceIndex++;
213 super.visitEnd();
214 }
215 }
216
217 }
218 |
Popular Tags |
Java API By Example, From Geeks To Geeks.