groovy.lang.MetaMethod Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of groovy Show documentation
Show all versions of groovy Show documentation
Groovy: A powerful, dynamic language for the JVM
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.classgen.asm.BytecodeHelper;
import org.codehaus.groovy.reflection.CachedClass;
import org.codehaus.groovy.reflection.ParameterTypes;
import org.codehaus.groovy.runtime.InvokerHelper;
import org.codehaus.groovy.runtime.MetaClassHelper;
import java.lang.reflect.Modifier;
/**
* Represents a Method on a Java object a little like {@link java.lang.reflect.Method}
* except without using reflection to invoke the method
*
* @author James Strachan
* @author Alex Tkachman
*/
public abstract class MetaMethod extends ParameterTypes implements Cloneable {
private String signature;
private String mopName;
/**
* Constructor for a metamethod with an empty parameter list
*/
public MetaMethod() {
}
/**
*Constructor wit a list of parameter classes
*
* @param pt A list of parameters types
*/
public MetaMethod(Class [] pt) {
super (pt);
}
/**
*Returns the modifiers for this method
*
* @return modifiers as an int.
*/
public abstract int getModifiers();
/**
* Returns the name of the method represented by this class
*
* @return name of this method
*/
public abstract String getName();
/**
* Access the return type for this method
*
*@return the return type of this method
*/
public abstract Class getReturnType();
/**
* Gets the class where this method is declared
*
* @return class of this method
*/
public abstract CachedClass getDeclaringClass();
/**
* Invoke this method
*
* @param object The object this method should be invoked on
* @param arguments The arguments for the method if applicable
* @return The return value of the invocation
*/
public abstract Object invoke(Object object, Object[] arguments);
/**
* Checks that the given parameters are valid to call this method
*
* @param arguments the arguments to check
* @throws IllegalArgumentException if the parameters are not valid
*/
public void checkParameters(Class[] arguments) {
// lets check that the argument types are valid
if (!isValidMethod(arguments)) {
throw new IllegalArgumentException(
"Parameters to method: "
+ getName()
+ " do not match types: "
+ InvokerHelper.toString(getParameterTypes())
+ " for arguments: "
+ InvokerHelper.toString(arguments));
}
}
/**
*Returns true if this this metamethod represents the same method as the argument.
*
* @param method A metaMethod instance
* @return true if method is for the same method as this method, false otherwise.
*/
public boolean isMethod(MetaMethod method) {
return getName().equals(method.getName())
&& getModifiers() == method.getModifiers()
&& getReturnType().equals(method.getReturnType())
&& equal(getParameterTypes(), method.getParameterTypes());
}
protected static boolean equal(CachedClass[] a, Class[] b) {
if (a.length == b.length) {
for (int i = 0, size = a.length; i < size; i++) {
if (!a[i].getTheClass().equals(b[i])) {
return false;
}
}
return true;
}
return false;
}
protected static boolean equal(CachedClass[] a, CachedClass[] b) {
if (a.length == b.length) {
for (int i = 0, size = a.length; i < size; i++) {
if (a[i] != b[i]) {
return false;
}
}
return true;
}
return false;
}
/**
* Returns a string representation of this method
*/
public String toString() {
return super.toString()
+ "[name: "
+ getName()
+ " params: "
+ InvokerHelper.toString(getParameterTypes())
+ " returns: "
+ getReturnType()
+ " owner: "
+ getDeclaringClass()
+ "]";
}
public Object clone() {
try {
return super.clone();
}
catch (CloneNotSupportedException e) {
throw new GroovyRuntimeException("This should never happen", e);
}
}
/**
* Returns whether or not this method is static.
* @return true if this method is static
*/
public boolean isStatic() {
return (getModifiers() & Modifier.STATIC) != 0;
}
/**
* Returns whether or not this method is abstract.
* @return true if this method is abstract
*/
public boolean isAbstract() {
return (getModifiers() & Modifier.ABSTRACT) != 0;
}
/**
* Returns whether or not this method is private.
* @return true if this method is private
*/
public final boolean isPrivate() {
return (getModifiers() & Modifier.PRIVATE) != 0;
}
/**
* Returns whether or not this method is protected.
* @return true if this method is protected
*/
public final boolean isProtected() {
return (getModifiers() & Modifier.PROTECTED) != 0;
}
/**
* Returns whether or not this method is public.
* @return true if this method is public
*/
public final boolean isPublic() {
return (getModifiers() & Modifier.PUBLIC) != 0;
}
/**
* @param method the method to compare against
* @return true if the given method has the same name, parameters, return type
* and modifiers but may be defined on another type
*/
public final boolean isSame(MetaMethod method) {
return getName().equals(method.getName())
&& compatibleModifiers(getModifiers(), method.getModifiers())
&& getReturnType().equals(method.getReturnType())
&& equal(getParameterTypes(), method.getParameterTypes());
}
/**
* Checks the compatibility between two modifier masks. Checks that they are equal
* with regards to access and static modifier.
*
* @return true if the modifiers are compatible
*/
private static boolean compatibleModifiers(int modifiersA, int modifiersB) {
int mask = Modifier.PRIVATE | Modifier.PROTECTED | Modifier.PUBLIC | Modifier.STATIC;
return (modifiersA & mask) == (modifiersB & mask);
}
/**
* Returns whether this object is cacheable
*/
public boolean isCacheable() {
return true;
}
/**
* Return a descriptor of this method based on the return type and parameters of this method.
*/
public String getDescriptor() {
return BytecodeHelper.getMethodDescriptor(getReturnType(), getNativeParameterTypes());
}
/**
* Returns the signature of this method
*
* @return The signature of this method
*/
public synchronized String getSignature() {
if (signature == null) {
CachedClass [] parameters = getParameterTypes();
final String name = getName();
StringBuilder buf = new StringBuilder(name.length()+parameters.length*10);
buf.append(getReturnType().getName());
buf.append(' ');
buf.append(name);
buf.append('(');
for (int i = 0; i < parameters.length; i++) {
if (i > 0) {
buf.append(", ");
}
buf.append(parameters[i].getName());
}
buf.append(')');
signature = buf.toString();
}
return signature;
}
public String getMopName() {
if (mopName == null) {
String name = getName();
CachedClass declaringClass = getDeclaringClass();
if (Modifier.isPrivate(getModifiers()))
mopName = new StringBuffer().append("this$").append(declaringClass.getSuperClassDistance()).append("$").append(name).toString();
else
mopName = new StringBuffer().append("super$").append(declaringClass.getSuperClassDistance()).append("$").append(name).toString();
}
return mopName;
}
/**
* This method is called when an exception occurs while invoking this method.
*/
public final RuntimeException processDoMethodInvokeException (Exception e, Object object, Object [] argumentArray) {
// if (e instanceof IllegalArgumentException) {
// //TODO: test if this is OK with new MOP, should be changed!
// // we don't want the exception being unwrapped if it is a IllegalArgumentException
// // but in the case it is for example a IllegalThreadStateException, we want the unwrapping
// // from the runtime
// //Note: the reason we want unwrapping sometimes and sometimes not is that the method
// // invocation tries to invoke the method with and then reacts with type transformation
// // if the invocation failed here. This is OK for IllegalArgumentException, but it is
// // possible that a Reflector will be used to execute the call and then an Exception from inside
// // the method is not wrapped in a InvocationTargetException and we will end here.
// boolean setReason = e.getClass() != IllegalArgumentException.class || this instanceof org.codehaus.groovy.reflection.GeneratedMetaMethod;
// return MetaClassHelper.createExceptionText("failed to invoke method: ", this, object, argumentArray, e, setReason);
// }
if (e instanceof RuntimeException)
return (RuntimeException) e;
return MetaClassHelper.createExceptionText("failed to invoke method: ", this, object, argumentArray, e, true);
}
/**
* Invokes the method this object represents. This method is not final but it should be overloaded very carefully and only by generated methods
* there is no guarantee that it will be called
*
* @param object The object the method is to be called at.
* @param argumentArray Arguments for the method invocation.
* @return The return value of the invoked method.
*/
public Object doMethodInvoke(Object object, Object[] argumentArray) {
argumentArray = coerceArgumentsToClasses(argumentArray);
try {
return invoke(object, argumentArray);
} catch (Exception e) {
throw processDoMethodInvokeException(e, object, argumentArray);
}
}
}