/*
* Copyright 2011 JBoss, by Red Hat, Inc
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jboss.errai.codegen;
import static org.jboss.errai.codegen.util.Stmt.loadVariable;
import static org.jboss.errai.codegen.util.Stmt.throw_;
import org.jboss.errai.codegen.builder.BlockBuilder;
import org.jboss.errai.codegen.builder.ClassStructureBuilder;
import org.jboss.errai.codegen.builder.impl.ClassBuilder;
import org.jboss.errai.codegen.exception.UnproxyableClassException;
import org.jboss.errai.codegen.meta.MetaClass;
import org.jboss.errai.codegen.meta.MetaClassFactory;
import org.jboss.errai.codegen.meta.MetaMethod;
import org.jboss.errai.codegen.meta.MetaParameter;
import org.jboss.errai.codegen.meta.MetaParameterizedType;
import org.jboss.errai.codegen.meta.MetaType;
import org.jboss.errai.codegen.meta.MetaTypeVariable;
import org.jboss.errai.codegen.meta.impl.build.BuildMetaClass;
import org.jboss.errai.codegen.util.GenUtil;
import org.jboss.errai.codegen.util.If;
import org.jboss.errai.codegen.util.PrivateAccessUtil;
import org.jboss.errai.codegen.util.Refs;
import org.jboss.errai.codegen.util.Stmt;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
/**
* @author Mike Brock
*/
public class ProxyMaker {
public static BuildMetaClass makeProxy(final String proxyClassName, final Class cls) {
return makeProxy(proxyClassName, cls, "reflection");
}
public static BuildMetaClass makeProxy(final String proxyClassName,
final Class cls,
final String privateAccessorType) {
return makeProxy(proxyClassName, MetaClassFactory.get(cls), privateAccessorType);
}
public static final String PROXY_BIND_METHOD = "__$setProxiedInstance$";
public static BuildMetaClass makeProxy(final String proxyClassName,
final MetaClass toProxy) {
return makeProxy(proxyClassName, toProxy, "reflection");
}
public static BuildMetaClass makeProxy(final String proxyClassName,
final MetaClass toProxy,
final String privateAccessorType) {
final ClassStructureBuilder builder;
final boolean renderEqualsAndHash;
if (!toProxy.isInterface()) {
renderEqualsAndHash = true;
if (toProxy.isFinal()) {
throw new UnproxyableClassException(toProxy, toProxy.getFullyQualifiedName()
+ " is an unproxiable class because it is final");
}
if (!toProxy.isDefaultInstantiable()) {
throw new UnproxyableClassException(toProxy, toProxy.getFullyQualifiedName() + " must have a default " +
"no-arg constructor");
}
builder = ClassBuilder.define(proxyClassName, toProxy).publicScope().body();
}
else {
renderEqualsAndHash = false;
builder = ClassBuilder.define(proxyClassName).publicScope().implementsInterface(toProxy).body();
}
final String proxyVar = "$$_proxy_$$";
final Set<String> renderedMethods = new HashSet<String>();
final Map<String, MetaType> typeVariableMap = new HashMap<String, MetaType>();
final MetaParameterizedType metaParameterizedType = toProxy.getParameterizedType();
if (metaParameterizedType != null) {
int i = 0;
for (final MetaTypeVariable metaTypeVariable : toProxy.getTypeParameters()) {
typeVariableMap.put(metaTypeVariable.getName(), metaParameterizedType.getTypeParameters()[i++]);
}
}
builder.privateField(proxyVar, toProxy).finish();
for (final MetaMethod method : toProxy.getMethods()) {
final String methodString = GenUtil.getMethodString(method);
if (renderedMethods.contains(methodString) || method.getName().equals("hashCode")
|| (method.getName().equals("equals") && method.getParameters().length == 1
&& method.getParameters()[0].getType().getFullyQualifiedName().equals(Object.class.getName()))) continue;
renderedMethods.add(methodString);
if ((!method.isPublic() && !method.isProtected()) ||
method.isSynthetic() ||
method.isFinal() ||
method.isStatic() ||
method.getDeclaringClass().getFullyQualifiedName().equals(Object.class.getName()))
continue;
final List<Parameter> methodParms = new ArrayList<Parameter>();
final MetaParameter[] parameters = method.getParameters();
final MetaType[] genericParmTypes = method.getGenericParameterTypes();
if (genericParmTypes != null && genericParmTypes.length == parameters.length) {
for (int i = 0, genericParmTypesLength = genericParmTypes.length; i < genericParmTypesLength; i++) {
MetaType type = genericParmTypes[i];
MetaClass parmType = parameters[i].getType();
if (type instanceof MetaTypeVariable) {
final MetaTypeVariable typeVariable = (MetaTypeVariable) type;
if (typeVariableMap.containsKey(typeVariable.getName())) {
final MetaType typeVar = typeVariableMap.get(typeVariable.getName());
if (typeVar instanceof MetaClass) {
parmType = (MetaClass) typeVar;
}
}
}
methodParms.add(Parameter.of(parmType, "a" + i));
}
}
final DefParameters defParameters = DefParameters.fromParameters(methodParms);
final BlockBuilder methBody = builder.publicMethod(method.getReturnType(), method.getName())
.parameters(defParameters)
.throws_(method.getCheckedExceptions());
final List<Parameter> parms = defParameters.getParameters();
final Statement[] statementVars = new Statement[parms.size()];
for (int i = 0; i < parms.size(); i++) {
statementVars[i] = loadVariable(parms.get(i).getName());
}
if (!method.isPublic()) {
PrivateAccessUtil.addPrivateAccessStubs(privateAccessorType, builder, method, new Modifier[0]);
final Statement[] privateAccessStmts = new Statement[statementVars.length + 1];
privateAccessStmts[0] = Refs.get(proxyVar);
for (int i = 0; i < statementVars.length; i++) {
privateAccessStmts[i + 1] = statementVars[i];
}
if (method.getReturnType().isVoid()) {
methBody._(loadVariable("this").invoke(PrivateAccessUtil.getPrivateMethodName(method), privateAccessStmts));
}
else {
methBody._(loadVariable("this").invoke(PrivateAccessUtil.getPrivateMethodName(method), privateAccessStmts).returnValue());
}
}
else {
if (method.getReturnType().isVoid()) {
methBody._(loadVariable(proxyVar).invoke(method, statementVars));
}
else {
methBody._(loadVariable(proxyVar).invoke(method, statementVars).returnValue());
}
}
methBody.finish();
}
if (renderEqualsAndHash) {
// implement hashCode()
builder.publicMethod(int.class, "hashCode").body()
._(
If.isNull(loadVariable(proxyVar))
._(throw_(IllegalStateException.class, "call to hashCode() on an unclosed proxy."))
.finish()
.else_()
._(Stmt.loadVariable(proxyVar).invoke("hashCode").returnValue())
.finish()
)
.finish();
// implements equals()
builder.publicMethod(boolean.class, "equals", Parameter.of(Object.class, "o")).body()
._(
If.isNull(loadVariable(proxyVar))
._(throw_(IllegalStateException.class, "call to equal() on an unclosed proxy."))
.finish()
.else_()
._(Stmt.loadVariable(proxyVar).invoke("equals", Refs.get("o")).returnValue())
.finish()
)
.finish();
}
builder.publicMethod(void.class, PROXY_BIND_METHOD).parameters(DefParameters.of(Parameter.of(toProxy, "proxy")))
._(loadVariable(proxyVar).assignValue(loadVariable("proxy"))).finish();
return builder.getClassDefinition();
}
}