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Diffstat (limited to 'sandbox/rfeng/minicore/src/main/java/org/apache/tuscany/core/util/JavaIntrospectionHelper.java')
| -rw-r--r-- | sandbox/rfeng/minicore/src/main/java/org/apache/tuscany/core/util/JavaIntrospectionHelper.java | 439 |
1 files changed, 0 insertions, 439 deletions
diff --git a/sandbox/rfeng/minicore/src/main/java/org/apache/tuscany/core/util/JavaIntrospectionHelper.java b/sandbox/rfeng/minicore/src/main/java/org/apache/tuscany/core/util/JavaIntrospectionHelper.java deleted file mode 100644 index 6b11725481..0000000000 --- a/sandbox/rfeng/minicore/src/main/java/org/apache/tuscany/core/util/JavaIntrospectionHelper.java +++ /dev/null @@ -1,439 +0,0 @@ -/* - * 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 org.apache.tuscany.core.util; - -import java.lang.reflect.Constructor; -import java.lang.reflect.Field; -import java.lang.reflect.Method; -import java.lang.reflect.Modifier; -import java.lang.reflect.ParameterizedType; -import java.lang.reflect.Type; -import java.util.ArrayList; -import java.util.HashSet; -import java.util.List; -import java.util.Set; - -/** - * Implements various reflection-related operations - * - * @version $Rev$ $Date$ - */ -public final class JavaIntrospectionHelper { - - private static final Class[] EMPTY_CLASS_ARRY = new Class[0]; - - /** - * Hide the constructor - */ - private JavaIntrospectionHelper() { - } - - - /** - * Returns a collection of public, and protected fields declared by a class or one of its supertypes - */ - public static Set<Field> getAllPublicAndProtectedFields(Class clazz) { - return getAllPublicAndProtectedFields(clazz, new HashSet<Field>()); - } - - /** - * Recursively evaluates the type hierachy to return all fields that are public or protected - */ - private static Set<Field> getAllPublicAndProtectedFields(Class clazz, Set<Field> fields) { - if (clazz == null || clazz.isArray() || Object.class.equals(clazz)) { - return fields; - } - fields = getAllPublicAndProtectedFields(clazz.getSuperclass(), fields); - Field[] declaredFields = clazz.getDeclaredFields(); - for (Field field : declaredFields) { - int modifiers = field.getModifiers(); - if ((Modifier.isPublic(modifiers) || Modifier.isProtected(modifiers)) && !Modifier.isStatic(modifiers)) { - field.setAccessible(true); // ignore Java accessibility - fields.add(field); - } - } - return fields; - } - - /** - * Returns a collection of public and protected methods declared by a class or one of its supertypes. Note that - * overriden methods will not be returned in the collection (i.e. only the method override will be). <p/> This - * method can potentially be expensive as reflection information is not cached. It is assumed that this method will - * be used during a configuration phase. - */ - public static Set<Method> getAllUniquePublicProtectedMethods(Class clazz) { - return getAllUniqueMethods(clazz, new HashSet<Method>()); - } - - /** - * Recursively evaluates the type hierarchy to return all unique methods - */ - private static Set<Method> getAllUniqueMethods(Class pClass, Set<Method> methods) { - if (pClass == null || pClass.isArray() || Object.class.equals(pClass)) { - return methods; - } - // we first evaluate methods of the subclass and then move to the parent - Method[] declaredMethods = pClass.getDeclaredMethods(); - for (Method declaredMethod : declaredMethods) { - int modifiers = declaredMethod.getModifiers(); - if ((!Modifier.isPublic(modifiers) && !Modifier.isProtected(modifiers)) || Modifier.isStatic(modifiers)) { - continue; - } - if (methods.size() == 0) { - methods.add(declaredMethod); - } else { - List<Method> temp = new ArrayList<Method>(); - boolean matched = false; - for (Method method : methods) { - // only add if not already in the set from a supclass (i.e. the - // method is not overrided) - if (exactMethodMatch(declaredMethod, method)) { - matched = true; - break; - } - } - if (!matched) { - // TODO ignore Java accessibility - declaredMethod.setAccessible(true); - temp.add(declaredMethod); - } - methods.addAll(temp); - temp.clear(); - } - } - // evaluate class hierarchy - this is done last to track inherited methods - methods = getAllUniqueMethods(pClass.getSuperclass(), methods); - return methods; - } - - /** - * Finds the closest matching field with the given name, that is, a field of the exact specified type or, - * alternately, of a supertype. - * - * @param name the name of the field - * @param type the field type - * @param fields the collection of fields to search - * @return the matching field or null if not found - */ - public static Field findClosestMatchingField(String name, Class type, Set<Field> fields) { - Field candidate = null; - for (Field field : fields) { - if (field.getName().equals(name)) { - if (field.getType().equals(type)) { - return field; // exact match - } else if (field.getType().isAssignableFrom(type) - || (field.getType().isPrimitive() && primitiveAssignable(field.getType(), type))) { - // We could have the situation where a field parameter is a primitive and the demarshalled value is - // an object counterpart (e.g. Integer and int) - // @spec issue - // either an interface or super class, so keep a reference until - // we know there are no closer types - candidate = field; - } - } - } - if (candidate != null) { - return candidate; - } else { - return null; - } - } - - /** - * Finds the closest matching method with the given name, that is, a method taking the exact parameter types or, - * alternately, parameter supertypes. - * - * @param name the name of the method - * @param types the method parameter types - * @param methods the collection of methods to search - * @return the matching method or null if not found - */ - public static Method findClosestMatchingMethod(String name, Class[] types, Set<Method> methods) { - if (types == null) { - types = EMPTY_CLASS_ARRY; - } - Method candidate = null; - for (Method method : methods) { - if (method.getName().equals(name) && method.getParameterTypes().length == types.length) { - Class<?>[] params = method.getParameterTypes(); - boolean disqualify = false; - boolean exactMatch = true; - for (int i = 0; i < params.length; i++) { - if (!params[i].equals(types[i]) && !params[i].isAssignableFrom(types[i])) { - // no match - disqualify = true; - exactMatch = false; - break; - } else if (!params[i].equals(types[i]) && params[i].isAssignableFrom(types[i])) { - // not exact match - exactMatch = false; - } - } - if (disqualify) { - continue; - } else if (exactMatch) { - return method; - } else { - candidate = method; - } - } - } - if (candidate != null) { - return candidate; - } else { - return null; - } - } - - /** - * Searches a collection of fields for one that matches by name and has a multiplicity type. i.e. a List or Array of - * interfaces - * - * @return a matching field or null - */ - public static Field findMultiplicityFieldByName(String name, Set<Field> fields) { - for (Field candidate : fields) { - if (candidate.getName().equals(name) - && (List.class.isAssignableFrom(candidate.getType()) || (candidate.getType().isArray() - && candidate.getType().getComponentType() != null && candidate.getType().getComponentType() - .isInterface()))) { - return candidate; - } - } - return null; - } - - /** - * Searches a collection of method for one that matches by name and has single parameter of a multiplicity type. - * i.e. a List or Array of interfaces - * - * @return a matching method or null - */ - public static Method findMultiplicityMethodByName(String name, Set<Method> methods) { - for (Method candidate : methods) { - if (candidate.getName().equals(name) - && candidate.getParameterTypes().length == 1 - && (List.class.isAssignableFrom(candidate.getParameterTypes()[0]) - || (candidate.getParameterTypes()[0].isArray() - && candidate.getParameterTypes()[0].getComponentType() != null - && candidate.getParameterTypes()[0].getComponentType().isInterface()))) { - return candidate; - } - } - return null; - } - - /** - * Determines if two methods "match" - that is, they have the same method names and exact parameter types (one is - * not a supertype of the other) - */ - public static boolean exactMethodMatch(Method method1, Method method2) { - if (!method1.getName().equals(method2.getName())) { - return false; - } - Class[] types1 = method1.getParameterTypes(); - Class[] types2 = method2.getParameterTypes(); - if (types1.length == 0 && types2.length == 0) { - return true; - } else if (types1.length == types2.length) { - for (int n = 0; n < types1.length; n++) { - if (!types1[n].equals(types2[n])) { - return false; - } - } - return true; - } - return false; - } - - public static <T> Constructor<T> getDefaultConstructor(Class<T> clazz) throws NoSuchMethodException { - return clazz.getConstructor((Class[]) null); - } - - /** - * Loads a class corresponding to the class name using the current context class loader. - * - * @throws ClassNotFoundException if the class was not found on the classpath - */ - public static Class loadClass(String pName) throws ClassNotFoundException { - ClassLoader loader = Thread.currentThread().getContextClassLoader(); - return Class.forName(pName, true, loader); - } - - /** - * Returns the simple name of a class - i.e. the class name devoid of its package qualifier - * - * @param implClass the implmentation class - */ - public static String getBaseName(Class<?> implClass) { - String baseName = implClass.getName(); - int lastDot = baseName.lastIndexOf('.'); - if (lastDot != -1) { - baseName = baseName.substring(lastDot + 1); - } - return baseName; - } - - public static boolean isImmutable(Class clazz) { - return String.class == clazz - || clazz.isPrimitive() - || Number.class.isAssignableFrom(clazz) - || Boolean.class.isAssignableFrom(clazz) - || Character.class.isAssignableFrom(clazz) - || Byte.class.isAssignableFrom(clazz); - } - - /** - * Takes a property name and converts it to a getter method name according to JavaBean conventions. For example, - * property <code>foo<code> is returned as <code>getFoo</code> - */ - public static String toGetter(String name) { - return "get" + name.toUpperCase().substring(0, 1) + name.substring(1); - } - - /** - * Takes a setter or getter method name and converts it to a property name according to JavaBean conventions. For - * example, <code>setFoo(var)</code> is returned as property <code>foo<code> - */ - public static String toPropertyName(String name) { - if (!name.startsWith("set")) { - return name; - } - return Character.toLowerCase(name.charAt(3)) + name.substring(4); - } - - /** - * Takes a property name and converts it to a setter method name according to JavaBean conventions. For example, the - * property <code>foo<code> is returned as <code>setFoo(var)</code> - */ - public static String toSetter(String name) { - return "set" + name.toUpperCase().substring(0, 1) + name.substring(1); - } - - /** - * Compares a two types, assuming one is a primitive, to determine if the other is its object counterpart - */ - private static boolean primitiveAssignable(Class memberType, Class param) { - if (memberType == Integer.class) { - return param == Integer.TYPE; - } else if (memberType == Double.class) { - return param == Double.TYPE; - } else if (memberType == Float.class) { - return param == Float.TYPE; - } else if (memberType == Short.class) { - return param == Short.TYPE; - } else if (memberType == Character.class) { - return param == Character.TYPE; - } else if (memberType == Boolean.class) { - return param == Boolean.TYPE; - } else if (memberType == Byte.class) { - return param == Byte.TYPE; - } else if (param == Integer.class) { - return memberType == Integer.TYPE; - } else if (param == Double.class) { - return memberType == Double.TYPE; - } else if (param == Float.class) { - return memberType == Float.TYPE; - } else if (param == Short.class) { - return memberType == Short.TYPE; - } else if (param == Character.class) { - return memberType == Character.TYPE; - } else if (param == Boolean.class) { - return memberType == Boolean.TYPE; - } else if (param == Byte.class) { - return memberType == Byte.TYPE; - } else { - return false; - } - } - - /** - * Returns the generic types represented in the given type. Usage as follows: <code> - * JavaIntrospectionHelper.getGenerics(field.getGenericType()); - * <p/> - * JavaIntrospectionHelper.getGenerics(m.getGenericParameterTypes()[0];); </code> - * - * @return the generic types in order of declaration or an empty array if the type is not genericized - */ - public static List<? extends Type> getGenerics(Type genericType) { - List<Type> classes = new ArrayList<Type>(); - if (genericType instanceof ParameterizedType) { - ParameterizedType ptype = (ParameterizedType) genericType; - // get the type arguments - Type[] targs = ptype.getActualTypeArguments(); - for (Type targ : targs) { - classes.add(targ); - } - } - return classes; - } - - /** - * Returns the generic type specified by the class at the given position as in: - * <p/> - * <code> public class Foo<Bar,Baz>{ //.. } - * <p/> - * JavaIntrospectionHelper.introspectGeneric(Foo.class,1); <code> - * <p/> - * will return Baz. - */ - public static Class introspectGeneric(Class<?> clazz, int pos) { - assert clazz != null : "No class specified"; - Type type = clazz.getGenericSuperclass(); - if (type instanceof ParameterizedType) { - Type[] args = ((ParameterizedType) type).getActualTypeArguments(); - if (args.length <= pos) { - throw new IllegalArgumentException("Invalid index value for generic class " + clazz.getName()); - } - return (Class) ((ParameterizedType) type).getActualTypeArguments()[pos]; - } else { - Type[] interfaces = clazz.getGenericInterfaces(); - for (Type itype : interfaces) { - if (!(itype instanceof ParameterizedType)) { - continue; - } - ParameterizedType interfaceType = (ParameterizedType) itype; - return (Class) interfaceType.getActualTypeArguments()[0]; - } - } - return null; - } - - /** - * Returns the set of interfaces implemented by the given class and its ancestors or a blank set if none - */ - public static Set<Class> getAllInterfaces(Class clazz) { - Set<Class> implemented = new HashSet<Class>(); - getAllInterfaces(clazz, implemented); - return implemented; - } - - private static void getAllInterfaces(Class clazz, Set<Class> implemented) { - Class[] interfaces = clazz.getInterfaces(); - for (Class interfaze : interfaces) { - implemented.add(interfaze); - } - Class<?> superClass = clazz.getSuperclass(); - // Object has no superclass so check for null - if (superClass != null && !superClass.equals(Object.class)) { - getAllInterfaces(superClass, implemented); - } - } - -} |