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* Copyright (c) 2008, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package com.sun.beans.finder;
import com.sun.beans.TypeResolver;
import com.sun.beans.util.Cache;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.Arrays;
import static com.sun.beans.util.Cache.Kind.SOFT;
import static sun.reflect.misc.ReflectUtil.isPackageAccessible;
/**
* This utility class provides {@code static} methods
* to find a public method with specified name and parameter types
* in specified class.
*
* @since 1.7
*
* @author Sergey A. Malenkov
*/
public final class MethodFinder extends AbstractFinder<Method> {
private static final Cache<Signature, Method> CACHE = new Cache<Signature, Method>(SOFT, SOFT) {
@Override
public Method create(Signature signature) {
try {
MethodFinder finder = new MethodFinder(signature.getName(), signature.getArgs());
return findAccessibleMethod(finder.find(signature.getType().getMethods()));
}
catch (Exception exception) {
throw new SignatureException(exception);
}
}
};
/**
* Finds public method (static or non-static)
* that is accessible from public class.
*
* @param type the class that can have method
* @param name the name of method to find
* @param args parameter types that is used to find method
* @return object that represents found method
* @throws NoSuchMethodException if method could not be found
* or some methods are found
*/
public static Method findMethod(Class<?> type, String name, Class<?>...args) throws NoSuchMethodException {
if (name == null) {
throw new IllegalArgumentException("Method name is not set");
}
PrimitiveWrapperMap.replacePrimitivesWithWrappers(args);
Signature signature = new Signature(type, name, args);
try {
Method method = CACHE.get(signature);
return (method == null) || isPackageAccessible(method.getDeclaringClass()) ? method : CACHE.create(signature);
}
catch (SignatureException exception) {
throw exception.toNoSuchMethodException("Method '" + name + "' is not found");
}
}
/**
* Finds public non-static method
* that is accessible from public class.
*
* @param type the class that can have method
* @param name the name of method to find
* @param args parameter types that is used to find method
* @return object that represents found method
* @throws NoSuchMethodException if method could not be found
* or some methods are found
*/
public static Method findInstanceMethod(Class<?> type, String name, Class<?>... args) throws NoSuchMethodException {
Method method = findMethod(type, name, args);
if (Modifier.isStatic(method.getModifiers())) {
throw new NoSuchMethodException("Method '" + name + "' is static");
}
return method;
}
/**
* Finds public static method
* that is accessible from public class.
*
* @param type the class that can have method
* @param name the name of method to find
* @param args parameter types that is used to find method
* @return object that represents found method
* @throws NoSuchMethodException if method could not be found
* or some methods are found
*/
public static Method findStaticMethod(Class<?> type, String name, Class<?>...args) throws NoSuchMethodException {
Method method = findMethod(type, name, args);
if (!Modifier.isStatic(method.getModifiers())) {
throw new NoSuchMethodException("Method '" + name + "' is not static");
}
return method;
}
/**
* Finds method that is accessible from public class or interface through class hierarchy.
*
* @param method object that represents found method
* @return object that represents accessible method
* @throws NoSuchMethodException if method is not accessible or is not found
* in specified superclass or interface
*/
public static Method findAccessibleMethod(Method method) throws NoSuchMethodException {
Class<?> type = method.getDeclaringClass();
if (!FinderUtils.isExported(type)) {
throw new NoSuchMethodException("Method '" + method.getName() + "' is not accessible");
}
if (Modifier.isPublic(type.getModifiers()) && isPackageAccessible(type)) {
return method;
}
if (Modifier.isStatic(method.getModifiers())) {
throw new NoSuchMethodException("Method '" + method.getName() + "' is not accessible");
}
for (Type generic : type.getGenericInterfaces()) {
try {
return findAccessibleMethod(method, generic);
}
catch (NoSuchMethodException exception) {
// try to find in superclass or another interface
}
}
return findAccessibleMethod(method, type.getGenericSuperclass());
}
/**
* Finds method that accessible from specified class.
*
* @param method object that represents found method
* @param generic generic type that is used to find accessible method
* @return object that represents accessible method
* @throws NoSuchMethodException if method is not accessible or is not found
* in specified superclass or interface
*/
private static Method findAccessibleMethod(Method method, Type generic) throws NoSuchMethodException {
String name = method.getName();
Class<?>[] params = method.getParameterTypes();
if (generic instanceof Class) {
Class<?> type = (Class<?>) generic;
return findAccessibleMethod(type.getMethod(name, params));
}
if (generic instanceof ParameterizedType) {
ParameterizedType pt = (ParameterizedType) generic;
Class<?> type = (Class<?>) pt.getRawType();
for (Method m : type.getMethods()) {
if (m.getName().equals(name)) {
Class<?>[] pts = m.getParameterTypes();
if (pts.length == params.length) {
if (Arrays.equals(params, pts)) {
return findAccessibleMethod(m);
}
Type[] gpts = m.getGenericParameterTypes();
if (params.length == gpts.length) {
if (Arrays.equals(params, TypeResolver.erase(TypeResolver.resolve(pt, gpts)))) {
return findAccessibleMethod(m);
}
}
}
}
}
}
throw new NoSuchMethodException("Method '" + name + "' is not accessible");
}
private final String name;
/**
* Creates method finder with specified array of parameter types.
*
* @param name the name of method to find
* @param args the array of parameter types
*/
private MethodFinder(String name, Class<?>[] args) {
super(args);
this.name = name;
}
/**
* Checks validness of the method.
* The valid method should be public and
* should have the specified name.
*
* @param method the object that represents method
* @return {@code true} if the method is valid,
* {@code false} otherwise
*/
@Override
protected boolean isValid(Method method) {
return super.isValid(method) && method.getName().equals(this.name);
}
}