BeanDesc.java

/*
 * Copyright 2004-2010 the Seasar Foundation and the Others.
 *
 * 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 org.slim3.util;

import java.lang.reflect.Method;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;


/**
 * This class describes bean information.
 * 
 * @author higa
 * @since 1.0.0
 * 
 */
public final class BeanDesc {

    private Class<?> beanClass;

    private CaseInsensitiveMap<PropertyDesc> propertyDescCache =
        new CaseInsensitiveMap<PropertyDesc>();

    /**
     * Constructor.
     * 
     * @param beanClass
     *            the bean class
     */
    BeanDesc(Class<?> beanClass) {
        this.beanClass = beanClass;
    }

    /**
     * Creates the bean descriptor.
     * 
     * @param beanClass
     *            the bean class
     * @return the bean descriptor
     * @throws NullPointerException
     *             if the beanClass parameter is null
     */
    public static BeanDesc create(Class<?> beanClass) {
        if (beanClass == null) {
            throw new NullPointerException("The beanClass parameter is null.");
        }
        BeanDesc beanDesc = new BeanDesc(beanClass);
        setupPropertyDesc(beanDesc);
        return beanDesc;
    }

    private static void setupPropertyDesc(BeanDesc beanDesc) {
        Set<String> illegalPropertyNames = new HashSet<String>();
        Method[] methods = beanDesc.beanClass.getMethods();
        for (int i = 0; i < methods.length; i++) {
            Method m = methods[i];
            if (m.isBridge()
                || m.isSynthetic()
                || m.getDeclaringClass() == Object.class) {
                continue;
            }
            String methodName = m.getName();
            if (methodName.startsWith("get")) {
                if (m.getParameterTypes().length != 0
                    || m.getReturnType() == void.class) {
                    continue;
                }
                String propertyName =
                    StringUtil.decapitalize(methodName.substring(3));
                setupReadMethod(beanDesc, m, propertyName, illegalPropertyNames);
            } else if (methodName.startsWith("is")) {
                if (m.getParameterTypes().length != 0
                    || m.getReturnType() != boolean.class) {
                    continue;
                }
                String propertyName =
                    StringUtil.decapitalize(methodName.substring(2));
                setupReadMethod(beanDesc, m, propertyName, illegalPropertyNames);
            } else if (methodName.startsWith("set")) {
                if (m.getParameterTypes().length != 1
                    || m.getReturnType() != void.class) {
                    continue;
                }
                String propertyName =
                    StringUtil.decapitalize(methodName.substring(3));
                setupWriteMethod(
                    beanDesc,
                    m,
                    propertyName,
                    illegalPropertyNames);
            }
        }
        for (Iterator<String> i = illegalPropertyNames.iterator(); i.hasNext();) {
            beanDesc.propertyDescCache.remove(i.next());
        }
    }

    private static void setupReadMethod(BeanDesc beanDesc, Method readMethod,
            String propertyName, Set<String> illegalPropertyNames) {
        Class<?> propertyClass = readMethod.getReturnType();
        PropertyDesc propDesc = beanDesc.propertyDescCache.get(propertyName);
        if (propDesc != null) {
            if (!propDesc.getPropertyClass().equals(propertyClass)) {
                illegalPropertyNames.add(propertyName);
            } else {
                propDesc.setReadMethod(readMethod);
            }
        } else {
            propDesc =
                new PropertyDesc(
                    propertyName,
                    propertyClass,
                    beanDesc.beanClass);
            propDesc.setReadMethod(readMethod);
            beanDesc.propertyDescCache.put(propertyName, propDesc);
        }
    }

    private static void setupWriteMethod(BeanDesc beanDesc, Method writeMethod,
            String propertyName, Set<String> illegalPropertyNames) {
        Class<?> propertyClass = writeMethod.getParameterTypes()[0];
        PropertyDesc propDesc = beanDesc.propertyDescCache.get(propertyName);
        if (propDesc != null) {
            if (!propDesc.getPropertyClass().equals(propertyClass)) {
                illegalPropertyNames.add(propertyName);
            } else {
                propDesc.setWriteMethod(writeMethod);
            }
        } else {
            propDesc =
                new PropertyDesc(
                    propertyName,
                    propertyClass,
                    beanDesc.beanClass);
            propDesc.setWriteMethod(writeMethod);
            beanDesc.propertyDescCache.put(propertyName, propDesc);
        }
    }

    /**
     * Returns the bean class.
     * 
     * @return the bean class
     */
    public Class<?> getBeanClass() {
        return beanClass;
    }

    /**
     * Returns the property descriptor.
     * 
     * @param propertyName
     *            the property name
     * @return the property descriptor
     */
    public PropertyDesc getPropertyDesc(String propertyName) {
        return propertyDescCache.get(propertyName);
    }

    /**
     * Returns the property descriptor for index.
     * 
     * @param index
     *            the index
     * @return the property descriptor
     */
    public PropertyDesc getPropertyDesc(int index) {
        return propertyDescCache.get(index);
    }

    /**
     * Returns the number of property descriptors.
     * 
     * @return the number of property descriptors.
     */
    public int getPropertyDescSize() {
        return propertyDescCache.size();
    }
}