/**
* Creates a visitor which will be used as a base class for initiating the visit. It is not
* necessary that the class is the superclass, any will do, as long as it can be loaded from a
* byte[].
*
* @param baseClass
* @return
*/
private ClassReader createClassVisitor(final Class baseClass) {
try {
String name = baseClass.getName();
String path = name.replace('.', '/') + ".class";
InputStream in = loader.getResourceAsStream(path);
return new ClassReader(in);
} catch (IOException e) {
throw new GroovyRuntimeException(
"Unable to generate a proxy for " + baseClass + " from class loader " + loader, e);
}
}
/**
* Construct a proxy generator. This generator is used when we need to create a proxy object for a
* class or an interface given a map of closures.
*
* @param closureMap the delegates implementations
* @param superClass corresponding to the superclass class visitor
* @param interfaces extra interfaces the proxy should implement
* @param proxyLoader the class loader which should be used to load the generated proxy
* @param delegateClass if not null, generate a delegate field with the corresponding class
* @param emptyBody if set to true, the unimplemented abstract methods will receive an empty body
* instead of throwing an {@link UnsupportedOperationException}.
*/
public ProxyGeneratorAdapter(
final Map<Object, Object> closureMap,
final Class superClass,
final Class[] interfaces,
final ClassLoader proxyLoader,
final boolean emptyBody,
final Class delegateClass) {
super(new ClassWriter(0));
this.visitedMethods = new LinkedHashSet<Object>();
this.delegatedClosures =
closureMap.isEmpty() ? EMPTY_DELEGATECLOSURE_MAP : new HashMap<String, Boolean>();
boolean wildcard = false;
for (Map.Entry<Object, Object> entry : closureMap.entrySet()) {
String name = entry.getKey().toString();
if ("*".equals(name)) {
wildcard = true;
}
this.delegatedClosures.put(name, Boolean.FALSE);
}
this.hasWildcard = wildcard;
// if we have to delegate to another object, generate the appropriate delegate field
// and collect the name of the methods for which delegation is active
this.generateDelegateField = delegateClass != null;
this.objectDelegateMethods =
generateDelegateField
? createDelegateMethodList(delegateClass, interfaces)
: EMPTY_STRING_SET;
this.delegateClass = delegateClass;
// a proxy is supposed to be a concrete class, so it cannot extend an interface.
// If the provided superclass is an interface, then we replace the superclass with Object
// and add this interface to the list of implemented interfaces
boolean isSuperClassAnInterface = superClass.isInterface();
this.superClass = isSuperClassAnInterface ? Object.class : superClass;
// create the base list of classes which have possible methods to be overloaded
this.classList = new LinkedList<Class>();
this.classList.add(superClass);
if (generateDelegateField) {
classList.add(delegateClass);
}
if (interfaces != null) {
Collections.addAll(this.classList, interfaces);
}
this.proxyName = proxyName();
this.loader = proxyLoader != null ? new InnerLoader(proxyLoader) : findClassLoader(superClass);
this.emptyBody = emptyBody;
// generate bytecode
ClassWriter writer = (ClassWriter) cv;
ClassReader cr = createClassVisitor(Object.class);
cr.accept(this, 0);
byte[] b = writer.toByteArray();
// CheckClassAdapter.verify(new ClassReader(b), true, new PrintWriter(System.err));
cachedClass = loader.defineClass(proxyName.replace('/', '.'), b);
// cache no-arg constructor
Class[] args =
generateDelegateField ? new Class[] {Map.class, delegateClass} : new Class[] {Map.class};
Constructor constructor;
try {
constructor = cachedClass.getConstructor(args);
} catch (NoSuchMethodException e) {
constructor = null;
}
cachedNoArgConstructor = constructor;
}