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Groovy example source code file (ExpandoMetaClass.java)
This example Groovy source code file (ExpandoMetaClass.java) is included in the DevDaily.com
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The Groovy ExpandoMetaClass.java source code
/*
* Copyright 2003-2010 the original author or authors.
*
* 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 groovy.lang;
import org.codehaus.groovy.reflection.CachedClass;
import org.codehaus.groovy.reflection.MixinInMetaClass;
import org.codehaus.groovy.runtime.DefaultCachedMethodKey;
import org.codehaus.groovy.runtime.DefaultGroovyMethods;
import org.codehaus.groovy.runtime.InvokerHelper;
import org.codehaus.groovy.runtime.MetaClassHelper;
import org.codehaus.groovy.runtime.MethodKey;
import org.codehaus.groovy.runtime.callsite.CallSite;
import org.codehaus.groovy.runtime.callsite.ConstructorMetaMethodSite;
import org.codehaus.groovy.runtime.callsite.PogoMetaClassSite;
import org.codehaus.groovy.runtime.callsite.PojoMetaClassSite;
import org.codehaus.groovy.runtime.callsite.StaticMetaClassSite;
import org.codehaus.groovy.runtime.metaclass.ClosureMetaMethod;
import org.codehaus.groovy.runtime.metaclass.ClosureStaticMetaMethod;
import org.codehaus.groovy.runtime.metaclass.DefaultMetaClassInfo;
import org.codehaus.groovy.runtime.metaclass.MixedInMetaClass;
import org.codehaus.groovy.runtime.metaclass.MixinInstanceMetaMethod;
import org.codehaus.groovy.runtime.metaclass.OwnedMetaClass;
import org.codehaus.groovy.runtime.metaclass.ThreadManagedMetaBeanProperty;
import org.codehaus.groovy.util.FastArray;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
/**
* ExpandoMetaClass is a MetaClass that behaves like an Expando, allowing the addition or replacement
* of methods, properties and constructors on the fly.
* <p/>
* Some examples of usage:
* <pre>
* // defines or replaces instance method:
* metaClass.myMethod = { args -> }
* <p/>
* // defines a new instance method
* metaClass.myMethod << { args -> }
* <p/>
* // creates multiple overloaded methods of the same name
* metaClass.myMethod << { String s -> } << { Integer i -> }
* <p/>
* // defines or replaces a static method with the 'static' qualifier
* metaClass.'static'.myMethod = { args -> }
* <p/>
* // defines a new static method with the 'static' qualifier
* metaClass.'static'.myMethod << { args -> }
* <p/>
* // defines a new constructor
* metaClass.constructor << { String arg -> }
* <p/>
* // defines or replaces a constructor
* metaClass.constructor = { String arg -> }
* <p/>
* // defines a new property with an initial value of "blah"
* metaClass.myProperty = "blah"
* </pre>
* <p/>
* ExpandoMetaClass also supports a DSL/builder like notation to combine multiple definitions together. So instead of this:
* <pre>
* Number.metaClass.multiply = { Amount amount -> amount.times(delegate) }
* Number.metaClass.div = { Amount amount -> amount.inverse().times(delegate) }
* </pre>
* You can also now do this:
* <pre>
* Number.metaClass {
* multiply { Amount amount -> amount.times(delegate) }
* div { Amount amount -> amount.inverse().times(delegate) }
* }
* </pre>
* <p/>
* ExpandoMetaClass also supports runtime mixins. While {@code @Mixin} allows you to mix in new behavior
* to classes you own and are designing, you can not easily mixin anything to types you didn't own, e.g.
* from third party libraries or from JDK library classes.
* Runtime mixins let you add a mixin on any type at runtime.
* <pre>
* interface Vehicle {
* String getName()
* }
* <p/>
* // Category annotation style
* {@code @Category}(Vehicle) class FlyingAbility {
* def fly() { "I'm the ${name} and I fly!" }
* }
* <p/>
* // traditional category style
* class DivingAbility {
* static dive(Vehicle self) { "I'm the ${self.name} and I dive!" }
* }
* <p/>
* // provided by a third-party, so can't augment using Mixin annotation
* class JamesBondVehicle implements Vehicle {
* String getName() { "James Bond's vehicle" }
* }
* <p/>
* // Can be added via metaClass, e.g.:
* // JamesBondVehicle.metaClass.mixin DivingAbility, FlyingAbility
* // Or using shorthand through DGM method on Class
* JamesBondVehicle.mixin DivingAbility, FlyingAbility
* <p/>
* assert new JamesBondVehicle().fly() ==
* "I'm the James Bond's vehicle and I fly!"
* assert new JamesBondVehicle().dive() ==
* "I'm the James Bond's vehicle and I dive!"
* </pre>
* As another example, consider the following class definitions:
* <pre>
* class Student {
* List<String> schedule = []
* def addLecture(String lecture) { schedule << lecture }
* }
* <p/>
* class Worker {
* List<String> schedule = []
* def addMeeting(String meeting) { schedule << meeting }
* }
* </pre>
* We can mimic a form of multiple inheritance as follows:
* <pre>
* class CollegeStudent {
* static { mixin Student, Worker }
* }
* new CollegeStudent().with {
* addMeeting('Performance review with Boss')
* addLecture('Learn about Groovy Mixins')
* println schedule
* println mixedIn[Student].schedule
* println mixedIn[Worker].schedule
* }
* </pre>
* Which outputs these lines when run:
* <pre>
* [Performance review with Boss]
* [Learn about Groovy Mixins]
* [Performance review with Boss]
* </pre>
* Perhaps some explanation is required here. The methods and properties of Student and Worker are
* added to CollegeStudent. Worker is added last, so for overlapping methods, its methods will
* be used, e.g. when calling <code>schedule, it will be the schedule property (getSchedule method)
* from Worker that is used. The schedule property from Student will be shadowed but the <code>mixedIn
* notation allows us to get to that too if we need as the last two lines show.
* <p/>
* We can also be a little more dynamic and not require the CollegeStudent class to
* be defined at all, e.g.:
* <pre>
* def cs = new Object()
* cs.metaClass {
* mixin Student, Worker
* getSchedule {
* mixedIn[Student].schedule + mixedIn[Worker].schedule
* }
* }
* cs.with {
* addMeeting('Performance review with Boss')
* addLecture('Learn about Groovy Mixins')
* println schedule
* }
* </pre>
* Which outputs this line when run:
* <pre>
* [Learn about Groovy Mixins, Performance review with Boss]
* </pre>
* As another example, we can also define a no dup queue by mixing in some
* Queue and Set functionality as follows:
* <pre>
* def ndq = new Object()
* ndq.metaClass {
* mixin ArrayDeque
* mixin HashSet
* leftShift = { Object o ->
* if (!mixedIn[Set].contains(o)) {
* mixedIn[Queue].push(o)
* mixedIn[Set].add(o)
* }
* }
* }
* ndq << 1
* ndq << 2
* ndq << 1
* assert ndq.size() == 2
* </pre>
* As a final example, we sometimes need to pass such mixed in classes or objects
* into Java methods which require a given static type but the ExpandoMetaClass mixin approach uses a very dynamic
* approach based on duck typing rather than static interface definitions, so doesn't by default
* produce objects matching the required static type. Luckily, there is a mixins capability
* within ExpandoMetaClass which supports the use of Groovy's common 'as StaticType' notation to produce an object
* having the correct static type so that it can be passed to the Java method call in question.
* A slightly contrived example illustrating this feature:
* <pre>
* class CustomComparator implements Comparator {
* int compare(Object a, b) { return a.size() - b.size() }
* }
* <p/>
* class CustomCloseable implements Closeable {
* void close() { println 'Lights out - I am closing' }
* }
* <p/>
* import static mypackage.IOUtils.closeQuietly
* import static java.util.Collections.sort
* def o = new Object()
* o.metaClass.mixin CustomComparator, CustomCloseable
* def items = ['a', 'bbb', 'cc']
* sort(items, o as Comparator)
* println items // => [a, cc, bbb]
* closeQuietly(o as Closeable) // => Lights out - I am closing
* </pre>
* <p/>
* <b>Further details
* <p/>
* When using the default implementations of MetaClass, methods are only allowed to be added before initialize() is called.
* In other words you create a new MetaClass, add some methods and then call initialize(). If you attempt to add new methods
* after initialize() has been called, an error will be thrown. This is to ensure that the MetaClass can operate appropriately
* in multi-threaded environments as it forces you to do all method additions at the beginning, before using the MetaClass.
* <p/>
* ExpandoMetaClass differs here from the default in that it allows you to add methods after initialize has been called.
* This is done by setting the initialize flag internally to false and then add the methods. Since this is not thread
* safe it has to be done in a synchronized block. The methods to check for modification and initialization are
* therefore synchronized as well. Any method call done through this meta class will first check if the it is
* synchronized. Should this happen during a modification, then the method cannot be selected or called unless the
* modification is completed.
* <p/>
* WARNING: This MetaClass uses a thread-bound ThreadLocal instance to store and retrieve properties.
* In addition properties stored use soft references so they are both bound by the life of the Thread and by the soft
* references. The implication here is you should NEVER use dynamic properties if you want their values to stick around
* for long periods because as soon as the JVM is running low on memory or the thread dies they will be garbage collected.
*
* @author Graeme Rocher
* @since 1.5
*/
public class ExpandoMetaClass extends MetaClassImpl implements GroovyObject {
private static final String META_CLASS = "metaClass";
private static final String CLASS = "class";
private static final String META_METHODS = "metaMethods";
private static final String METHODS = "methods";
private static final String PROPERTIES = "properties";
public static final String STATIC_QUALIFIER = "static";
public static final String CONSTRUCTOR = "constructor";
private static final String CLASS_PROPERTY = "class";
private static final String META_CLASS_PROPERTY = "metaClass";
private static final String GROOVY_CONSTRUCTOR = "<init>";
// These two properties are used when no ExpandoMetaClassCreationHandle is present
private MetaClass myMetaClass;
private boolean initialized;
private volatile boolean modified;
private boolean initCalled;
final private boolean allowChangesAfterInit;
public boolean inRegistry;
private final Set<MetaMethod> inheritedMetaMethods = new HashSet();
private final Map<String, MetaProperty> beanPropertyCache = new ConcurrentHashMap();
private final Map<String, MetaProperty> staticBeanPropertyCache = new ConcurrentHashMap();
private final Map<MethodKey, MetaMethod> expandoMethods = new ConcurrentHashMap();
public Collection getExpandoSubclassMethods() {
return expandoSubclassMethods.values();
}
private final ConcurrentHashMap expandoSubclassMethods = new ConcurrentHashMap();
private final Map<String, MetaProperty> expandoProperties = new ConcurrentHashMap();
private ClosureStaticMetaMethod invokeStaticMethodMethod;
private final Set<MixinInMetaClass> mixinClasses = new LinkedHashSet();
private ExpandoMetaClass(Class theClass, boolean register, boolean allowChangesAfterInit, MetaMethod[] add) {
super(GroovySystem.getMetaClassRegistry(), theClass, add);
this.myMetaClass = InvokerHelper.getMetaClass(getClass());
this.inRegistry = register;
this.allowChangesAfterInit = allowChangesAfterInit;
}
/**
* Constructs a new ExpandoMetaClass instance for the given class
*
* @param theClass The class that the MetaClass applies to
*/
public ExpandoMetaClass(Class theClass) {
this(theClass,false,false,null);
}
public ExpandoMetaClass(Class theClass, MetaMethod [] add) {
this(theClass,false,false,add);
}
/**
* Constructs a new ExpandoMetaClass instance for the given class optionally placing the MetaClass
* in the MetaClassRegistry automatically
*
* @param theClass The class that the MetaClass applies to
* @param register True if the MetaClass should be registered inside the MetaClassRegistry. This defaults to true and ExpandoMetaClass will effect all instances if changed
*/
public ExpandoMetaClass(Class theClass, boolean register) {
this(theClass,register,false,null);
}
public ExpandoMetaClass(Class theClass, boolean register, MetaMethod [] add) {
this(theClass, register, false, add);
}
/**
* Constructs a new ExpandoMetaClass instance for the given class optionally placing the MetaClass
* in the MetaClassRegistry automatically
*
* @param theClass The class that the MetaClass applies to
* @param register True if the MetaClass should be registered inside the MetaClassRegistry. This defaults to true and ExpandoMetaClass will effect all instances if changed
* @param allowChangesAfterInit Should the meta class be modifiable after initialization. Default is false.
*/
public ExpandoMetaClass(Class theClass, boolean register, boolean allowChangesAfterInit) {
this(theClass, register, allowChangesAfterInit, null);
}
public MetaMethod findMixinMethod(String methodName, Class[] arguments) {
for (MixinInMetaClass mixin : mixinClasses) {
final CachedClass mixinClass = mixin.getMixinClass();
MetaClass metaClass = mixinClass.classInfo.getMetaClassForClass();
if (metaClass == null) {
metaClass = GroovySystem.getMetaClassRegistry().getMetaClass(mixinClass.getTheClass());
}
MetaMethod metaMethod = metaClass.pickMethod(methodName, arguments);
if (metaMethod == null && metaClass instanceof MetaClassImpl) {
MetaClassImpl mc = (MetaClassImpl) metaClass;
for (CachedClass cl = mc.getTheCachedClass().getCachedSuperClass(); cl != null; cl = cl.getCachedSuperClass()) {
metaMethod = mc.getMethodWithoutCaching(cl.getTheClass(), methodName, arguments, false);
if (metaMethod != null)
break;
}
}
if (metaMethod != null) {
MetaMethod method = new MixinInstanceMetaMethod(metaMethod, mixin);
if (method.getParameterTypes().length == 1 && !method.getParameterTypes()[0].isPrimitive) {
MetaMethod noParam = pickMethod(methodName, new Class[0]);
// if the current call itself is with empty arg class array, no need to recurse with 'new Class[0]'
if (noParam == null && arguments.length != 0) {
findMixinMethod(methodName, new Class[0]);
}
}
registerInstanceMethod(method);
return method;
}
}
return null;
}
protected void onInvokeMethodFoundInHierarchy(MetaMethod method) {
this.invokeMethodMethod = method;
}
protected void onSuperMethodFoundInHierarchy(MetaMethod method) {
addSuperMethodIfNotOverridden(method);
}
protected void onSuperPropertyFoundInHierarchy(MetaBeanProperty property) {
addMetaBeanProperty(property);
}
protected void onSetPropertyFoundInHierarchy(MetaMethod method) {
this.setPropertyMethod = method;
}
protected void onGetPropertyFoundInHierarchy(MetaMethod method) {
this.getPropertyMethod = method;
}
public boolean isModified() {
return this.modified;
}
public void registerSubclassInstanceMethod(String name, Class klazz, Closure closure) {
final List<MetaMethod> list = ClosureMetaMethod.createMethodList(name, klazz, closure);
for (MetaMethod metaMethod : list) {
registerSubclassInstanceMethod(metaMethod);
}
}
public void registerSubclassInstanceMethod(MetaMethod metaMethod) {
modified = true;
final String name = metaMethod.getName();
Object methodOrList = expandoSubclassMethods.get(name);
if (methodOrList == null) {
expandoSubclassMethods.put(name, metaMethod);
} else {
if (methodOrList instanceof MetaMethod) {
FastArray arr = new FastArray(2);
arr.add(methodOrList);
arr.add(metaMethod);
expandoSubclassMethods.put(name, arr);
} else {
((FastArray) methodOrList).add(metaMethod);
}
}
}
public void addMixinClass(MixinInMetaClass mixin) {
mixinClasses.add(mixin);
}
public Object castToMixedType(Object obj, Class type) {
for (MixinInMetaClass mixin : mixinClasses) {
if (type.isAssignableFrom(mixin.getMixinClass().getTheClass()))
return mixin.getMixinInstance(obj);
}
return null;
}
/**
* For simulating closures in Java
*/
private interface Callable {
void call();
}
/**
* Call to enable global use of global use of ExpandoMetaClass within the registry. This has the advantage that
* inheritance will function correctly, but has a higher memory usage on the JVM than normal Groovy
*/
public static void enableGlobally() {
DefaultMetaClassInfo.setWithoutCustomMetaclassCreationHandle(false);
ExpandoMetaClassCreationHandle.enable();
}
/**
* Call to disable the global use of ExpandoMetaClass
*/
public static void disableGlobally() {
DefaultMetaClassInfo.setWithoutCustomMetaclassCreationHandle(true);
ExpandoMetaClassCreationHandle.disable();
}
/* (non-Javadoc)
* @see groovy.lang.MetaClassImpl#initialize()
*/
public synchronized void initialize() {
if (!isInitialized()) {
super.initialize();
setInitialized(true);
this.initCalled = true;
}
}
/**
* Checks if the meta class is initialized.
* @see groovy.lang.MetaClassImpl#isInitialized()
*/
protected synchronized boolean isInitialized() {
return this.initialized;
}
protected synchronized void setInitialized(boolean b) {
this.initialized = b;
}
private void addSuperMethodIfNotOverridden(final MetaMethod metaMethodFromSuper) {
performOperationOnMetaClass(new Callable() {
public void call() {
MetaMethod existing = null;
try {
existing = pickMethod(metaMethodFromSuper.getName(), metaMethodFromSuper.getNativeParameterTypes());
} catch ( GroovyRuntimeException e) {
// ignore, this happens with overlapping method definitions
}
if (existing == null) {
addMethodWithKey(metaMethodFromSuper);
} else {
boolean isGroovyMethod = getMetaMethods().contains(existing);
if (isGroovyMethod) {
addMethodWithKey(metaMethodFromSuper);
} else if (inheritedMetaMethods.contains(existing)) {
inheritedMetaMethods.remove(existing);
addMethodWithKey(metaMethodFromSuper);
}
}
}
private void addMethodWithKey(final MetaMethod metaMethodFromSuper) {
inheritedMetaMethods.add(metaMethodFromSuper);
if (metaMethodFromSuper instanceof ClosureMetaMethod) {
ClosureMetaMethod closureMethod = (ClosureMetaMethod)metaMethodFromSuper;
String name = metaMethodFromSuper.getName();
final Class declaringClass = metaMethodFromSuper.getDeclaringClass().getTheClass();
ClosureMetaMethod localMethod = ClosureMetaMethod.copy(closureMethod);
addMetaMethod(localMethod);
MethodKey key = new DefaultCachedMethodKey(declaringClass, name, localMethod.getParameterTypes(), false);
checkIfGroovyObjectMethod(localMethod);
expandoMethods.put(key, localMethod);
}
}
});
}
/**
* Instances of this class are returned when using the << left shift operator.
* <p/>
* Example:
* <p/>
* metaClass.myMethod << { String args -> }
* <p/>
* This allows callbacks to the ExpandoMetaClass for registering appending methods
*
* @author Graeme Rocher
*/
protected class ExpandoMetaProperty extends GroovyObjectSupport {
protected String propertyName;
protected boolean isStatic;
protected ExpandoMetaProperty(String name) {
this(name, false);
}
protected ExpandoMetaProperty(String name, boolean isStatic) {
this.propertyName = name;
this.isStatic = isStatic;
}
public String getPropertyName() {
return this.propertyName;
}
public boolean isStatic() {
return this.isStatic;
}
public Object leftShift(Object arg) {
registerIfClosure(arg, false);
return this;
}
private void registerIfClosure(Object arg, boolean replace) {
if (arg instanceof Closure) {
Closure callable = (Closure) arg;
final List<MetaMethod> list = ClosureMetaMethod.createMethodList(propertyName, theClass, callable);
if (list.isEmpty() && this.isStatic) {
Class[] paramTypes = callable.getParameterTypes();
registerStatic(callable, replace, paramTypes);
return;
}
for (MetaMethod method : list) {
Class[] paramTypes = method.getNativeParameterTypes();
if (this.isStatic) {
registerStatic(callable, replace, paramTypes);
} else {
registerInstance(method, replace, paramTypes);
}
}
}
}
private void registerStatic(Closure callable, boolean replace, Class[] paramTypes) {
Method foundMethod = checkIfMethodExists(theClass, propertyName, paramTypes, true);
if (foundMethod != null && !replace)
throw new GroovyRuntimeException("Cannot add new static method [" + propertyName + "] for arguments [" + DefaultGroovyMethods.inspect(paramTypes) + "]. It already exists!");
registerStaticMethod(propertyName, callable, paramTypes);
}
private void registerInstance(MetaMethod method, boolean replace, Class[] paramTypes) {
Method foundMethod = checkIfMethodExists(theClass, propertyName, paramTypes, false);
if (foundMethod != null && !replace)
throw new GroovyRuntimeException("Cannot add new method [" + propertyName + "] for arguments [" + DefaultGroovyMethods.inspect(paramTypes) + "]. It already exists!");
registerInstanceMethod(method);
}
private Method checkIfMethodExists(Class methodClass, String methodName, Class[] paramTypes, boolean staticMethod) {
Method foundMethod = null;
Method[] methods = methodClass.getMethods();
for (Method method : methods) {
if (method.getName().equals(methodName) && Modifier.isStatic(method.getModifiers()) == staticMethod) {
if (MetaClassHelper.parametersAreCompatible(paramTypes, method.getParameterTypes())) {
foundMethod = method;
break;
}
}
}
return foundMethod;
}
/* (non-Javadoc)
* @see groovy.lang.GroovyObjectSupport#getProperty(java.lang.String)
*/
public Object getProperty(String property) {
this.propertyName = property;
return this;
}
/* (non-Javadoc)
* @see groovy.lang.GroovyObjectSupport#setProperty(java.lang.String, java.lang.Object)
*/
public void setProperty(String property, Object newValue) {
this.propertyName = property;
registerIfClosure(newValue, true);
}
}
/* (non-Javadoc)
* @see groovy.lang.MetaClassImpl#invokeConstructor(java.lang.Object[])
*/
public Object invokeConstructor(Object[] arguments) {
// TODO This is the only area where this MetaClass needs to do some interception because Groovy's current
// MetaClass uses hard coded references to the java.lang.reflect.Constructor class so you can't simply
// inject Constructor like you can do properties, methods and fields. When Groovy's MetaClassImpl is
// refactored we can fix this
Class[] argClasses = MetaClassHelper.convertToTypeArray(arguments);
MetaMethod method = pickMethod(GROOVY_CONSTRUCTOR, argClasses);
if (method != null && method.getParameterTypes().length == arguments.length) {
return method.invoke(theClass, arguments);
}
return super.invokeConstructor(arguments);
}
/**
* Handles the ability to use the left shift operator to append new constructors
*
* @author Graeme Rocher
*/
protected class ExpandoMetaConstructor extends GroovyObjectSupport {
public Object leftShift(Closure c) {
if (c != null) {
final List<MetaMethod> list = ClosureMetaMethod.createMethodList(GROOVY_CONSTRUCTOR, theClass, c);
for (MetaMethod method : list) {
Class[] paramTypes = method.getNativeParameterTypes();
Constructor ctor = retrieveConstructor(paramTypes);
if (ctor != null)
throw new GroovyRuntimeException("Cannot add new constructor for arguments [" + DefaultGroovyMethods.inspect(paramTypes) + "]. It already exists!");
registerInstanceMethod(method);
}
}
return this;
}
}
/* (non-Javadoc)
* @see groovy.lang.GroovyObject#getMetaClass()
*/
public MetaClass getMetaClass() {
return myMetaClass;
}
/* (non-Javadoc)
* @see groovy.lang.GroovyObject#getProperty(java.lang.String)
*/
public Object getProperty(String property) {
if (isValidExpandoProperty(property)) {
if (property.equals(STATIC_QUALIFIER)) {
return new ExpandoMetaProperty(property, true);
} else if (property.equals(CONSTRUCTOR)) {
return new ExpandoMetaConstructor();
} else {
if (myMetaClass.hasProperty(this, property) == null)
return new ExpandoMetaProperty(property);
else
return myMetaClass.getProperty(this, property);
}
} else {
return myMetaClass.getProperty(this, property);
}
}
public static boolean isValidExpandoProperty(String property) {
return !(property.equals(META_CLASS) || property.equals(CLASS) || property.equals(META_METHODS) || property.equals(METHODS) || property.equals(PROPERTIES));
}
/* (non-Javadoc)
* @see groovy.lang.GroovyObject#invokeMethod(java.lang.String, java.lang.Object)
*/
public Object invokeMethod(String name, Object args) {
final Object[] argsArr = args instanceof Object[] ? (Object[]) args : new Object[]{args};
MetaMethod metaMethod = myMetaClass.getMetaMethod(name, argsArr);
if (metaMethod != null) {
// we have to use doMethodInvoke here instead of simply invoke,
// because getMetaMethod may provide a method that can not be called
// without further argument transformation, which is done only in
// doMethodInvoke
return metaMethod.doMethodInvoke(this, argsArr);
}
if (argsArr.length == 2 && argsArr[0] instanceof Class && argsArr[1] instanceof Closure) {
if (argsArr[0] == theClass)
registerInstanceMethod(name, (Closure) argsArr[1]);
else {
registerSubclassInstanceMethod(name, (Class) argsArr[0], (Closure) argsArr[1]);
}
return null;
}
if (argsArr.length == 1 && argsArr[0] instanceof Closure) {
registerInstanceMethod(name, (Closure) argsArr[0]);
return null;
}
throw new MissingMethodException(name, getClass(), argsArr);
}
/* (non-Javadoc)
* @see groovy.lang.GroovyObject#setMetaClass(groovy.lang.MetaClass)
*/
public void setMetaClass(MetaClass metaClass) {
this.myMetaClass = metaClass;
}
/* (non-Javadoc)
* @see groovy.lang.GroovyObject#setProperty(java.lang.String, java.lang.Object)
*/
public void setProperty(String property, Object newValue) {
if (newValue instanceof Closure) {
if (property.equals(CONSTRUCTOR)) {
property = GROOVY_CONSTRUCTOR;
}
Closure callable = (Closure) newValue;
final List<MetaMethod> list = ClosureMetaMethod.createMethodList(property, theClass, callable);
for (MetaMethod method : list) {
// here we don't care if the method exists or not we assume the
// developer is responsible and wants to override methods where necessary
registerInstanceMethod(method);
}
} else {
registerBeanProperty(property, newValue);
}
}
public ExpandoMetaClass define(Closure closure) {
final DefiningClosure definer = new DefiningClosure();
Object delegate = closure.getDelegate();
closure.setDelegate(definer);
closure.setResolveStrategy(Closure.DELEGATE_ONLY);
closure.call((Object)null);
closure.setDelegate(delegate);
closure.setResolveStrategy(Closure.DELEGATE_FIRST);
definer.definition = false;
return this;
}
protected synchronized void performOperationOnMetaClass(Callable c) {
try {
if (allowChangesAfterInit) {
setInitialized(false);
}
c.call();
}
finally {
if (initCalled) {
setInitialized(true);
}
}
}
/**
* Registers a new bean property
*
* @param property The property name
* @param newValue The properties initial value
*/
public void registerBeanProperty(final String property, final Object newValue) {
performOperationOnMetaClass(new Callable() {
public void call() {
Class type = newValue == null ? Object.class : newValue.getClass();
MetaBeanProperty mbp = newValue instanceof MetaBeanProperty ? (MetaBeanProperty) newValue : new ThreadManagedMetaBeanProperty(theClass, property, type, newValue);
final MetaMethod getter = mbp.getGetter();
final MethodKey getterKey = new DefaultCachedMethodKey(theClass, getter.getName(), CachedClass.EMPTY_ARRAY, false);
final MetaMethod setter = mbp.getSetter();
final MethodKey setterKey = new DefaultCachedMethodKey(theClass, setter.getName(), setter.getParameterTypes(), false);
addMetaMethod(getter);
addMetaMethod(setter);
expandoMethods.put(setterKey, setter);
expandoMethods.put(getterKey, getter);
expandoProperties.put(mbp.getName(), mbp);
addMetaBeanProperty(mbp);
performRegistryCallbacks();
}
});
}
/**
* Registers a new instance method for the given method name and closure on this MetaClass
*
* @param metaMethod
*/
public void registerInstanceMethod(final MetaMethod metaMethod) {
final boolean inited = this.initCalled;
performOperationOnMetaClass(new Callable() {
public void call() {
String methodName = metaMethod.getName();
checkIfGroovyObjectMethod(metaMethod);
MethodKey key = new DefaultCachedMethodKey(theClass, methodName, metaMethod.getParameterTypes(), false);
if (isInitialized()) {
throw new RuntimeException("Already initialized, cannot add new method: " + metaMethod);
}
// we always adds meta methods to class itself
addMetaMethodToIndex(metaMethod, metaMethodIndex.getHeader(theClass));
dropMethodCache(methodName);
expandoMethods.put(key, metaMethod);
if (inited && isGetter(methodName, metaMethod.getParameterTypes())) {
String propertyName = getPropertyForGetter(methodName);
registerBeanPropertyForMethod(metaMethod, propertyName, true, false);
} else if (inited && isSetter(methodName, metaMethod.getParameterTypes())) {
String propertyName = getPropertyForSetter(methodName);
registerBeanPropertyForMethod(metaMethod, propertyName, false, false);
}
performRegistryCallbacks();
}
});
}
public void registerInstanceMethod(String name, Closure closure) {
final List<MetaMethod> list = ClosureMetaMethod.createMethodList(name, theClass, closure);
for (MetaMethod method : list) {
registerInstanceMethod(method);
}
}
/**
* Overrides the behavior of parent getMethods() method to make MetaClass aware of added Expando methods
*
* @return A list of MetaMethods
* @see MetaObjectProtocol#getMethods()
*/
public List<MetaMethod> getMethods() {
List<MetaMethod> methodList = new ArrayList();
methodList.addAll(this.expandoMethods.values());
methodList.addAll(super.getMethods());
return methodList;
}
public List<MetaProperty> getProperties() {
List<MetaProperty> propertyList = new ArrayList();
propertyList.addAll(super.getProperties());
return propertyList;
}
private void performRegistryCallbacks() {
MetaClassRegistry registry = GroovySystem.getMetaClassRegistry();
incVersion();
if (!modified) {
modified = true;
// Implementation note: By default Groovy uses soft references to store MetaClass
// this insures the registry doesn't grow and get out of hand. By doing this we're
// saying this this EMC will be a hard reference in the registry. As we're only
// going have a small number of classes that have modified EMC this is ok
if (inRegistry) {
MetaClass currMetaClass = registry.getMetaClass(theClass);
if (!(currMetaClass instanceof ExpandoMetaClass) && currMetaClass instanceof AdaptingMetaClass) {
((AdaptingMetaClass) currMetaClass).setAdaptee(this);
} else {
registry.setMetaClass(theClass, this);
}
}
}
}
private void registerBeanPropertyForMethod(MetaMethod metaMethod, String propertyName, boolean getter, boolean isStatic) {
Map<String, MetaProperty> propertyCache = isStatic ? staticBeanPropertyCache : beanPropertyCache;
MetaBeanProperty beanProperty = (MetaBeanProperty) propertyCache.get(propertyName);
if (beanProperty == null) {
if (getter)
beanProperty = new MetaBeanProperty(propertyName, Object.class, metaMethod, null);
else
beanProperty = new MetaBeanProperty(propertyName, Object.class, null, metaMethod);
propertyCache.put(propertyName, beanProperty);
} else {
if (getter) {
MetaMethod setterMethod = beanProperty.getSetter();
Class type = setterMethod != null ? setterMethod.getParameterTypes()[0].getTheClass() : Object.class;
beanProperty = new MetaBeanProperty(propertyName, type, metaMethod, setterMethod);
propertyCache.put(propertyName, beanProperty);
} else {
MetaMethod getterMethod = beanProperty.getGetter();
beanProperty = new MetaBeanProperty(propertyName, metaMethod.getParameterTypes()[0].getTheClass(), getterMethod, metaMethod);
propertyCache.put(propertyName, beanProperty);
}
}
expandoProperties.put(beanProperty.getName(), beanProperty);
addMetaBeanProperty(beanProperty);
}
protected void registerStaticMethod(final String name, final Closure callable) {
registerStaticMethod(name, callable, null);
}
/**
* Registers a new static method for the given method name and closure on this MetaClass
*
* @param name The method name
* @param callable The callable Closure
*/
protected void registerStaticMethod(final String name, final Closure callable, final Class[] paramTypes) {
performOperationOnMetaClass(new Callable() {
public void call() {
String methodName;
if (name.equals(METHOD_MISSING))
methodName = STATIC_METHOD_MISSING;
else if (name.equals(PROPERTY_MISSING))
methodName = STATIC_PROPERTY_MISSING;
else
methodName = name;
ClosureStaticMetaMethod metaMethod = null;
if (paramTypes != null) {
metaMethod = new ClosureStaticMetaMethod(methodName, theClass, callable, paramTypes);
} else {
metaMethod = new ClosureStaticMetaMethod(methodName, theClass, callable);
}
if (methodName.equals(INVOKE_METHOD_METHOD) && callable.getParameterTypes().length == 2) {
invokeStaticMethodMethod = metaMethod;
} else {
if (methodName.equals(METHOD_MISSING)) {
methodName = STATIC_METHOD_MISSING;
}
MethodKey key = new DefaultCachedMethodKey(theClass, methodName, metaMethod.getParameterTypes(), false);
addMetaMethod(metaMethod);
dropStaticMethodCache(methodName);
// cacheStaticMethod(key,metaMethod);
if (isGetter(methodName, metaMethod.getParameterTypes())) {
String propertyName = getPropertyForGetter(methodName);
registerBeanPropertyForMethod(metaMethod, propertyName, true, true);
} else if (isSetter(methodName, metaMethod.getParameterTypes())) {
String propertyName = getPropertyForSetter(methodName);
registerBeanPropertyForMethod(metaMethod, propertyName, false, true);
}
performRegistryCallbacks();
expandoMethods.put(key, metaMethod);
}
}
});
}
protected Object getSubclassMetaMethods(String methodName) {
if (!isModified())
return null;
return expandoSubclassMethods.get(methodName);
}
/**
* @return The Java class enhanced by this MetaClass
*/
public Class getJavaClass() {
return theClass;
}
/**
* Called from ExpandoMetaClassCreationHandle in the registry if it exists to
* set up inheritance handling
*
* @param modifiedSuperExpandos A list of modified super ExpandoMetaClass
*/
public void refreshInheritedMethods(Set modifiedSuperExpandos) {
for (Iterator i = modifiedSuperExpandos.iterator(); i.hasNext();) {
ExpandoMetaClass superExpando = (ExpandoMetaClass) i.next();
if (superExpando != this) {
refreshInheritedMethods(superExpando);
}
}
}
private void refreshInheritedMethods(ExpandoMetaClass superExpando) {
List<MetaMethod> metaMethods = superExpando.getExpandoMethods();
for (MetaMethod metaMethod : metaMethods) {
if (metaMethod.isStatic()) {
if (superExpando.getTheClass() != getTheClass())
continue; // don't inherit static methods except our own
registerStaticMethod(metaMethod.getName(), (Closure) ((ClosureStaticMetaMethod) metaMethod).getClosure().clone());
} else
addSuperMethodIfNotOverridden(metaMethod);
}
Collection<MetaProperty> metaProperties = superExpando.getExpandoProperties();
for (Object metaProperty : metaProperties) {
MetaBeanProperty property = (MetaBeanProperty) metaProperty;
expandoProperties.put(property.getName(), property);
addMetaBeanProperty(property);
}
}
/**
* Returns a list of expando MetaMethod instances added to this ExpandoMetaClass
*
* @return the expandoMethods
*/
public List<MetaMethod> getExpandoMethods() {
return Collections.unmodifiableList(DefaultGroovyMethods.toList(expandoMethods.values()));
}
/**
* Returns a list of MetaBeanProperty instances added to this ExpandoMetaClass
*
* @return the expandoProperties
*/
public Collection<MetaProperty> getExpandoProperties() {
return Collections.unmodifiableCollection(expandoProperties.values());
}
/**
* Overrides default implementation just in case invokeMethod has been overridden by ExpandoMetaClass
*
* @see groovy.lang.MetaClassImpl#invokeMethod(Class, Object, String, Object[], boolean, boolean)
*/
public Object invokeMethod(Class sender, Object object, String methodName, Object[] originalArguments, boolean isCallToSuper, boolean fromInsideClass) {
if (invokeMethodMethod != null) {
return invokeMethodMethod.invoke(object, new Object[]{methodName, originalArguments});
}
return super.invokeMethod(sender, object, methodName, originalArguments, isCallToSuper, fromInsideClass);
}
/**
* Overrides default implementation just in case a static invoke method has been set on ExpandoMetaClass
*
* @see MetaClassImpl#invokeStaticMethod(Object, String, Object[])
*/
public Object invokeStaticMethod(Object object, String methodName, Object[] arguments) {
if (invokeStaticMethodMethod != null) {
return invokeStaticMethodMethod.invoke(object, new Object[]{methodName, arguments});
}
return super.invokeStaticMethod(object, methodName, arguments);
}
/**
* Overrides default implementation just in case getProperty method has been overridden by ExpandoMetaClass
*
* @see MetaClassImpl#getProperty(Class, Object, String, boolean, boolean)
*/
public Object getProperty(Class sender, Object object, String name, boolean useSuper, boolean fromInsideClass) {
if (hasOverrideGetProperty(name) && getJavaClass().isInstance(object)) {
return getPropertyMethod.invoke(object, new Object[]{name});
}
if ("mixedIn".equals(name)) {
return new MixedInAccessor(object, mixinClasses);
}
return super.getProperty(sender, object, name, useSuper, fromInsideClass);
}
/**
* Overrides default implementation just in case getProperty method has been overridden by ExpandoMetaClass
*
* @see MetaClassImpl#getProperty(Object, String)
*/
public Object getProperty(Object object, String name) {
if (hasOverrideGetProperty(name) && getJavaClass().isInstance(object)) {
return getPropertyMethod.invoke(object, new Object[]{name});
}
return super.getProperty(object, name);
}
private boolean hasOverrideGetProperty(String name) {
return getPropertyMethod != null && !name.equals(META_CLASS_PROPERTY) && !name.equals(CLASS_PROPERTY);
}
/**
* Overrides default implementation just in case setProperty method has been overridden by ExpandoMetaClass
*
* @see MetaClassImpl#setProperty(Class, Object, String, Object, boolean, boolean)
*/
public void setProperty(Class sender, Object object, String name, Object newValue, boolean useSuper, boolean fromInsideClass) {
if (setPropertyMethod != null && !name.equals(META_CLASS_PROPERTY) && getJavaClass().isInstance(object)) {
setPropertyMethod.invoke(object, new Object[]{name, newValue});
return;
}
super.setProperty(sender, object, name, newValue, useSuper, fromInsideClass);
}
/**
* Looks up an existing MetaProperty by name
*
* @param name The name of the MetaProperty
* @return The MetaProperty or null if it doesn't exist
*/
public MetaProperty getMetaProperty(String name) {
MetaProperty mp = (MetaProperty) this.expandoProperties.get(name);
if (mp != null) return mp;
return super.getMetaProperty(name);
}
/**
* Returns true if the MetaClass has the given property
*
* @param name The name of the MetaProperty
* @return True it exists as a MetaProperty
*/
public boolean hasMetaProperty(String name) {
return getMetaProperty(name) != null;
}
/**
* Checks whether a MetaMethod for the given name and arguments exists
*
* @param name The name of the MetaMethod
* @param args The arguments to the meta method
* @return True if the method exists otherwise null
*/
public boolean hasMetaMethod(String name, Class[] args) {
return super.pickMethod(name, args) != null;
}
/**
* Determine if this method name suffix is a legitimate bean property name.
* Either the first or second letter must be upperCase for that to be true.
*/
private static boolean isPropertyName(String name) {
return ((name.length() > 0) && Character.isUpperCase(name.charAt(0))) || ((name.length() > 1) && Character.isUpperCase(name.charAt(1)));
}
/**
* Returns true if the name of the method specified and the number of arguments make it a javabean property
*
* @param name True if its a Javabean property
* @param args The arguments
* @return True if it is a javabean property method
*/
private boolean isGetter(String name, CachedClass[] args) {
if (name == null || name.length() == 0 || args == null) return false;
if (args.length != 0) return false;
if (name.startsWith("get")) {
name = name.substring(3);
return isPropertyName(name);
} else if (name.startsWith("is")) {
name = name.substring(2);
return isPropertyName(name);
}
return false;
}
/**
* Returns a property name equivalent for the given getter name or null if it is not a getter
*
* @param getterName The getter name
* @return The property name equivalent
*/
private String getPropertyForGetter(String getterName) {
if (getterName == null || getterName.length() == 0) return null;
if (getterName.startsWith("get")) {
String prop = getterName.substring(3);
return convertPropertyName(prop);
} else if (getterName.startsWith("is")) {
String prop = getterName.substring(2);
return convertPropertyName(prop);
}
return null;
}
private String convertPropertyName(String prop) {
if (Character.isDigit(prop.charAt(0))) {
return prop;
}
return java.beans.Introspector.decapitalize(prop);
}
/**
* Returns a property name equivalent for the given setter name or null if it is not a getter
*
* @param setterName The setter name
* @return The property name equivalent
*/
public String getPropertyForSetter(String setterName) {
if (setterName == null || setterName.length() == 0) return null;
if (setterName.startsWith("set")) {
String prop = setterName.substring(3);
return convertPropertyName(prop);
}
return null;
}
public boolean isSetter(String name, CachedClass[] args) {
if (name == null || name.length() == 0 || args == null) return false;
if (name.startsWith("set")) {
if (args.length != 1) return false;
name = name.substring(3);
return isPropertyName(name);
}
return false;
}
public CallSite createPojoCallSite(CallSite site, Object receiver, Object[] args) {
if (invokeMethodMethod != null)
return new PojoMetaClassSite(site, this);
return super.createPojoCallSite(site, receiver, args);
}
public CallSite createStaticSite(CallSite site, Object[] args) {
if (invokeStaticMethodMethod != null)
return new StaticMetaClassSite(site, this);
return super.createStaticSite(site, args);
}
public CallSite createPogoCallSite(CallSite site, Object[] args) {
if (invokeMethodMethod != null)
return new PogoMetaClassSite(site, this);
return super.createPogoCallSite(site, args);
}
public CallSite createPogoCallCurrentSite(CallSite site, Class sender, String name, Object[] args) {
if (invokeMethodMethod != null)
return new PogoMetaClassSite(site, this);
return super.createPogoCallCurrentSite(site, sender, args);
}
public CallSite createConstructorSite(CallSite site, Object[] args) {
Class[] params = MetaClassHelper.convertToTypeArray(args);
MetaMethod method = pickMethod(GROOVY_CONSTRUCTOR, params);
if (method != null && method.getParameterTypes().length == args.length) {
if (method.getDeclaringClass().getTheClass().equals(getTheClass())) {
return new ConstructorMetaMethodSite(site, this, method, params);
}
}
return super.createConstructorSite(site, args);
}
private class SubClassDefiningClosure extends GroovyObjectSupport {
private final Class klazz;
public SubClassDefiningClosure(Class klazz) {
this.klazz = klazz;
}
public Object invokeMethod(String name, Object obj) {
if (obj instanceof Object[]) {
Object args[] = (Object[]) obj;
if (args.length == 1 && args[0] instanceof Closure) {
registerSubclassInstanceMethod(name, klazz, (Closure) args[0]);
return null;
}
}
throw new MissingMethodException(name, getClass(), new Object[]{obj});
}
}
private class DefiningClosure extends GroovyObjectSupport {
boolean definition = true;
public void mixin(Class category) {
mixin(Collections.singletonList(category));
}
public void mixin(List categories) {
DefaultGroovyMethods.mixin(ExpandoMetaClass.this, categories);
}
public void mixin(Class[] categories) {
DefaultGroovyMethods.mixin(ExpandoMetaClass.this, categories);
}
public void define(Class subClass, Closure closure) {
final SubClassDefiningClosure definer = new SubClassDefiningClosure(subClass);
closure.setDelegate(definer);
closure.setResolveStrategy(Closure.DELEGATE_FIRST);
closure.call((Object)null);
}
public Object invokeMethod(String name, Object obj) {
try {
return getMetaClass().invokeMethod(this, name, obj);
}
catch (MissingMethodException mme) {
if (obj instanceof Object[]) {
if (STATIC_QUALIFIER.equals(name)) {
final StaticDefiningClosure staticDef = new StaticDefiningClosure();
Closure c = (Closure) ((Object[]) obj)[0];
c.setDelegate(staticDef);
c.setResolveStrategy(Closure.DELEGATE_ONLY);
c.call((Object)null);
return null;
}
Object args[] = (Object[]) obj;
if (args.length == 1 && args[0] instanceof Closure) {
registerInstanceMethod(name, (Closure) args[0]);
} else if (args.length == 2 && args[0] instanceof Class && args[1] instanceof Closure)
registerSubclassInstanceMethod(name, (Class) args[0], (Closure) args[1]);
else
ExpandoMetaClass.this.setProperty(name, ((Object[]) obj)[0]);
return null;
}
throw mme;
}
}
public void setProperty(String property, Object newValue) {
ExpandoMetaClass.this.setProperty(property, newValue);
}
public Object getProperty(String property) {
if (STATIC_QUALIFIER.equals(property))
return new StaticDefiningClosure();
if (definition)
return new ExpandoMetaProperty(property);
else
throw new MissingPropertyException(property, getClass());
}
}
private class StaticDefiningClosure extends ExpandoMetaProperty {
protected StaticDefiningClosure() {
super(STATIC_QUALIFIER, true);
}
public Object invokeMethod(String name, Object obj) {
if (obj instanceof Object[]) {
final Object[] args = (Object[]) obj;
if (args.length == 1 && args[0] instanceof Closure) {
registerStaticMethod(name, (Closure) args[0]);
return null;
}
}
throw new MissingMethodException(name, getClass(), obj instanceof Object[] ? (Object[]) obj : new Object[]{obj});
}
}
private static class MixedInAccessor {
private final Object object;
private final Set<MixinInMetaClass> mixinClasses;
public MixedInAccessor(Object object, Set<MixinInMetaClass> mixinClasses) {
this.object = object;
this.mixinClasses = mixinClasses;
}
public Object getAt(Class key) {
if (key.isAssignableFrom(object.getClass())) {
return new GroovyObjectSupport() {
{
final MetaClass ownMetaClass = InvokerHelper.getMetaClass(object.getClass());
setMetaClass(new OwnedMetaClass(ownMetaClass) {
protected Object getOwner() {
return object;
}
protected MetaClass getOwnerMetaClass(Object owner) {
return getAdaptee();
}
});
}
};
}
for (final MixinInMetaClass mixin : mixinClasses) {
if (key.isAssignableFrom(mixin.getMixinClass().getTheClass())) {
return new GroovyObjectSupport() {
{
final Object mixedInInstance = mixin.getMixinInstance(object);
setMetaClass(new OwnedMetaClass(InvokerHelper.getMetaClass(mixedInInstance)) {
@Override
protected Object getOwner() {
return mixedInInstance;
}
@Override
protected MetaClass getOwnerMetaClass(Object owner) {
return ((MixedInMetaClass) getAdaptee()).getAdaptee();
}
});
}
};
}
}
throw new RuntimeException("Class " + key + " isn't mixed in " + object.getClass());
}
public void putAt(Class key, Object value) {
for (MixinInMetaClass mixin : mixinClasses)
if (mixin.getMixinClass().getTheClass() == key) {
mixin.setMixinInstance(object, value);
return;
}
throw new RuntimeException("Class " + key + " isn't mixed in " + object.getClass());
}
}
}
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