集册 Java实例教程 不管属性是可见的还是隐藏的,或者是在给定的类,超类或已实现的接口中声明的,都调用属性的getter。

不管属性是可见的还是隐藏的,或者是在给定的类,超类或已实现的接口中声明的,都调用属性的getter。

欢马劈雪     最近更新时间:2020-01-02 10:19:05

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不管属性是可见的还是隐藏的,或者是在给定的类,超类或已实现的接口中声明的,都调用属性的getter。
/*时代Java公众号 - nowjava.com 提 供*/

/*

 * Copyright (c) 2012 Data Harmonisation Panel

 * 

 * All rights reserved. This program and the accompanying materials are made

 * available under the terms of the GNU Lesser General Public License as

 * published by the Free Software Foundation, either version 3 of the License,

 * or (at your option) any later version.

 * 

 * You should have received a copy of the GNU Lesser General Public License

 * along with this distribution. If not, see <http://www.gnu.org/licenses/>.

 * 

 * Contributors:

 *     HUMBOLDT EU Integrated Project #030962

 *     Data Harmonisation Panel <http://www.dhpanel.eu>

 */

import java.io.File;

import java.io.IOException;

import java.lang.reflect.Field;

import java.lang.reflect.InvocationTargetException;

import java.lang.reflect.Method;

import java.lang.reflect.Modifier;

import java.net.JarURLConnection;

import java.net.MalformedURLException;

import java.net.URI;

import java.net.URISyntaxException;

import java.net.URL;

import java.util.ArrayList;

import java.util.Collection;/*来 自 nowjava - 时代Java*/

import java.util.Enumeration;

import java.util.Iterator;

import java.util.List;

import java.util.jar.JarEntry;

import java.util.jar.JarFile;

import java.util.zip.ZipException;


public class Main{

    /**

     * Invokes a getter for a property, no matter if the getter is visible or

     * hidden or if it is declared in the given class or in a superclass or

     * implemented interface.

     * 

     * @param <T> the result type

     * @param bean the object to invoke the getter on

     * @param propertyName the name of the property to retrieve

     * @return the property's value

     * @throws IllegalArgumentException if the argument's type is invalid

     * @throws IllegalAccessException if the setter is not accessible

     * @throws InvocationTargetException if the setter throws an exception

     * @throws NoSuchMethodException if there is no setter for this property

     */

    public static <T> T getDeepProperty(Object bean, String propertyName)

            throws IllegalArgumentException, IllegalAccessException,

            InvocationTargetException, NoSuchMethodException {

        Method getter = findDeepGetter(bean.getClass(), propertyName, null);

        if (getter == null) {

            throw new NoSuchMethodException("There is " + //$NON-NLS-1$

                    "no getter for property " + propertyName); //$NON-NLS-1$

        }


        return ReflectionHelper.<T> invokeGetter(bean, getter);

    }

    /**

     * Returns a getter method for a given property, no matter if the method is

     * visible or hidden or if it is declared in the given class or in a

     * superclass or implemented interface.

     * 

     * @param c the class which would contain the getter method

     * @param property the property

     * @param propertyType the property's type (can be null if the type does not

     *            matter)

     * @return the getter or null if there is no getter for this property

     */

    public static Method findDeepGetter(Class<?> c, String property,

            Class<?> propertyType) {

        if (c == Object.class || c == null) {

            return null;

        }


        char[] propertyNameArr = property.toCharArray();

        propertyNameArr[0] = Character.toUpperCase(propertyNameArr[0]);

        String getterName = "get" + new String(propertyNameArr); //$NON-NLS-1$


        Method result = null;

        // search visible and hidden methods in this class

        Method[] methods = c.getDeclaredMethods();

        for (Method m : methods) {

            if (m.getName().equals(getterName)

                    && m.getParameterTypes().length == 0

                    && (propertyType == null || propertyType

                            .isAssignableFrom(m.getReturnType()))) {

                result = m;

                break;

            }

        }


        // search superclass and interfaces

        if (result == null) {

            result = findDeepGetter(c.getSuperclass(), property,

                    propertyType);

            if (result == null) {

                Class<?>[] interfaces = c.getInterfaces();

                for (Class<?> inter : interfaces) {

                    result = findDeepGetter(inter, property, propertyType);

                    if (result != null) {

                        break;

                    }

                }

            }

        }


        return result;

    }

    
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