无论如何，调用属性的吸气剂或获取匹配字段。
/* * 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; /* 时 代 J a v a 公 众 号 - N o w J a v a . c o m 提 供 */ 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; import java.util.Enumeration; import java.util.Iterator; import java.util.List; /** 时代Java公众号 - nowjava.com 提供 **/ import java.util.jar.JarEntry; import java.util.jar.JarFile; import java.util.zip.ZipException; public class Main{ /** * Invokes a getter for a property, or gets the matching field, no matter * what. * * @param bean the object to invoke the getter on * @param propertyName the name of the property to retrieve * @param valueClass the class of the property or field * @return the property's value * @throws IllegalArgumentException if the argument's type is invalid * @throws InvocationTargetException if the getter throws an exception * @throws IllegalStateException is the field could be found or accessed */ @SuppressWarnings("unchecked") public static <T> T getDeepPropertyOrField(Object bean, String propertyName, Class<T> valueClass) throws IllegalArgumentException, InvocationTargetException { try { return ReflectionHelper.getDeepProperty(bean, propertyName); } catch (NoSuchMethodException e) {/* ignore */ } catch (IllegalAccessException e) {/* ignore */ } // there is no getter for the property. try to get the field directly Field f = findDeepField(bean.getClass(), propertyName, valueClass); if (f == null) { throw new IllegalStateException("Could not find " + "field for property " + propertyName + " in class " + bean.getClass().getCanonicalName()); } boolean access = f.isAccessible(); f.setAccessible(true); try { return (T) f.get(bean); } catch (Exception e) { throw new IllegalStateException("Could not get " + "field for property " + propertyName + "in class " + bean.getClass().getCanonicalName(), e); } finally { f.setAccessible(access); } } /** * 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 field for a given property, no matter if the field is visible * or hidden or if it is declared in the given class or in a superclass. * * @param c the class which would contain the field * @param property the property * @param propertyType the property's type * @return the field or null if there is no field for this property */ public static Field findDeepField(Class<?> c, String property, Class<?> propertyType) { if (c == Object.class || c == null) { return null; } Field result = null; // search visible and hidden fields in this class Field[] fields = c.getDeclaredFields(); for (Field f : fields) { String fn = f.getName(); if (fn.charAt(0) == '_') { // handle code style fn = fn.substring(1); } if (fn.equals(property) && (propertyType == null || f.getType() .isAssignableFrom(propertyType))) { result = f; break; } } // search superclass if (result == null) { result = findDeepField(c.getSuperclass(), property, propertyType); } return result; } /** * 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,