IntrospectionUtil.java Source code

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Here is the source code for IntrospectionUtil.java

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//
//$Id: IntrospectionUtil.java 1540 2007-01-19 12:24:10Z janb $
//Copyright 2006 Mort Bay Consulting Pty. Ltd.
//------------------------------------------------------------------------
//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.
//

import java.lang.reflect.Field;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.util.Arrays;
import java.util.List;

public class IntrospectionUtil {

    public static boolean containsSameMethodSignature(Method method, Class c, boolean checkPackage) {
        if (checkPackage) {
            if (!c.getPackage().equals(method.getDeclaringClass().getPackage()))
                return false;
        }

        boolean samesig = false;
        Method[] methods = c.getDeclaredMethods();
        for (int i = 0; i < methods.length && !samesig; i++) {
            if (IntrospectionUtil.isSameSignature(method, methods[i]))
                samesig = true;
        }
        return samesig;
    }

    public static boolean containsSameFieldName(Field field, Class c, boolean checkPackage) {
        if (checkPackage) {
            if (!c.getPackage().equals(field.getDeclaringClass().getPackage()))
                return false;
        }

        boolean sameName = false;
        Field[] fields = c.getDeclaredFields();
        for (int i = 0; i < fields.length && !sameName; i++) {
            if (fields[i].getName().equals(field.getName()))
                sameName = true;
        }
        return sameName;
    }

    public static boolean isInheritable(Package pack, Member member) {
        if (pack == null)
            return false;
        if (member == null)
            return false;

        int modifiers = member.getModifiers();
        if (Modifier.isPublic(modifiers))
            return true;
        if (Modifier.isProtected(modifiers))
            return true;
        if (!Modifier.isPrivate(modifiers) && pack.equals(member.getDeclaringClass().getPackage()))
            return true;

        return false;
    }

    public static boolean checkParams(Class[] formalParams, Class[] actualParams, boolean strict) {
        if (formalParams == null && actualParams == null)
            return true;
        if (formalParams == null && actualParams != null)
            return false;
        if (formalParams != null && actualParams == null)
            return false;

        if (formalParams.length != actualParams.length)
            return false;

        if (formalParams.length == 0)
            return true;

        int j = 0;
        if (strict) {
            while (j < formalParams.length && formalParams[j].equals(actualParams[j]))
                j++;
        } else {
            while ((j < formalParams.length) && (formalParams[j].isAssignableFrom(actualParams[j]))) {
                j++;
            }
        }

        if (j != formalParams.length) {
            return false;
        }

        return true;
    }

    public static boolean isSameSignature(Method methodA, Method methodB) {
        if (methodA == null)
            return false;
        if (methodB == null)
            return false;

        List parameterTypesA = Arrays.asList(methodA.getParameterTypes());
        List parameterTypesB = Arrays.asList(methodB.getParameterTypes());

        if (methodA.getName().equals(methodB.getName()) && parameterTypesA.containsAll(parameterTypesB))
            return true;

        return false;
    }

    public static boolean isTypeCompatible(Class formalType, Class actualType, boolean strict) {
        if (formalType == null && actualType != null)
            return false;
        if (formalType != null && actualType == null)
            return false;
        if (formalType == null && actualType == null)
            return true;

        if (strict)
            return formalType.equals(actualType);
        else
            return formalType.isAssignableFrom(actualType);
    }

    protected static Method findInheritedMethod(Package pack, Class clazz, String methodName, Class[] args,
            boolean strictArgs) throws NoSuchMethodException {
        if (clazz == null)
            throw new NoSuchMethodException("No class");
        if (methodName == null)
            throw new NoSuchMethodException("No method name");

        Method method = null;
        Method[] methods = clazz.getDeclaredMethods();
        for (int i = 0; i < methods.length && method == null; i++) {
            if (methods[i].getName().equals(methodName) && isInheritable(pack, methods[i])
                    && checkParams(methods[i].getParameterTypes(), args, strictArgs))
                method = methods[i];
        }
        if (method != null) {
            return method;
        } else
            return findInheritedMethod(clazz.getPackage(), clazz.getSuperclass(), methodName, args, strictArgs);
    }

    protected static Field findInheritedField(Package pack, Class clazz, String fieldName, Class fieldType,
            boolean strictType) throws NoSuchFieldException {
        if (clazz == null)
            throw new NoSuchFieldException("No class");
        if (fieldName == null)
            throw new NoSuchFieldException("No field name");
        try {
            Field field = clazz.getDeclaredField(fieldName);
            if (isInheritable(pack, field) && isTypeCompatible(fieldType, field.getType(), strictType))
                return field;
            else
                return findInheritedField(clazz.getPackage(), clazz.getSuperclass(), fieldName, fieldType,
                        strictType);
        } catch (NoSuchFieldException e) {
            return findInheritedField(clazz.getPackage(), clazz.getSuperclass(), fieldName, fieldType, strictType);
        }
    }

}