package person.lb.reflect;/*** 房子* @author noboudns**/
public class House {//拥有者private String owner = "nobounds";//房间数private int roomNum = 3;//垃圾桶public String dustbin = "垃圾桶";public String getDustbin() {return dustbin;}private void turnOnTV() {System.out.println("打开电视……");}}

package person.lb.reflect;import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;public class KeyDemo {public static void main(String[] args) throws IllegalArgumentException, IllegalAccessException, InvocationTargetException, InstantiationException, ClassNotFoundException, SecurityException, NoSuchFieldException {Class<?> clazz = Class.forName("person.lb.reflect.House");String className = clazz.getName();System.out.println("户主是：" + className);Field[] fields = clazz.getDeclaredFields();System.out.println("看看家里都有什么东西:");for(Field field : fields ) {System.out.println("类型：" + field.getType() + "，名称：" + field.getName() + "，使用权限:" + Modifier.toString(field.getModifiers()));}System.out.println("再看看家里有什么好玩的:");Method[] methods = clazz.getDeclaredMethods();for(Method method : methods) {System.out.println("名字：" + method.getName() + "，需要的东西：" + method.getParameterTypes().toString()+ "，得到什么：" + method.getReturnType().toString());System.out.println("用用看效果怎么样，嘿嘿！");//设置为可访问的method.setAccessible(true);method.invoke(clazz.newInstance());}System.out.println("心情不错，把房子据为己有吧！");House house = (House) clazz.newInstance();Field field = clazz.getDeclaredField("ownerName");field.setAccessible(true);field.set(house, "thief");System.out.println("现在房子的主人是：" + house.getOwnerName() );}
}

户主是：person.lb.reflect.House
看看家里都有什么东西:
类型：class java.lang.String，名称：ownerName，使用权限:private
类型：int，名称：roomNum，使用权限:private
类型：class java.lang.String，名称：dustbin，使用权限:public
再看看家里有什么好玩的:
名字：getOwnerName，需要的东西：[Ljava.lang.Class;@3d4b7453，得到什么：class java.lang.String
用用看效果怎么样，嘿嘿！
名字：getDustbin，需要的东西：[Ljava.lang.Class;@1cc2ea3f，得到什么：class java.lang.String
用用看效果怎么样，嘿嘿！
名字：turnOnTV，需要的东西：[Ljava.lang.Class;@40a0dcd9，得到什么：void
用用看效果怎么样，嘿嘿！
打开电视……
心情不错，把房子据为己有吧！
现在房子的主人是：thief

……//如果类中的属性不是public修饰或者是final修饰并且属性是不可访问的，那么设置字段为可访问public static void makeAccessible(Field field) {if ((!Modifier.isPublic(field.getModifiers()) ||!Modifier.isPublic(field.getDeclaringClass().getModifiers()) ||Modifier.isFinal(field.getModifiers())) && !field.isAccessible()) { field.setAccessible(true);}}/*** Make the given method accessible, explicitly setting it accessible if* necessary. The {@code setAccessible(true)} method is only called* when actually necessary, to avoid unnecessary conflicts with a JVM* SecurityManager (if active).* @param method the method to make accessible* @see java.lang.reflect.Method#setAccessible*/public static void makeAccessible(Method method) {if ((!Modifier.isPublic(method.getModifiers()) ||!Modifier.isPublic(method.getDeclaringClass().getModifiers())) && !method.isAccessible()) {method.setAccessible(true);}}/*** Make the given constructor accessible, explicitly setting it accessible* if necessary. The {@code setAccessible(true)} method is only called* when actually necessary, to avoid unnecessary conflicts with a JVM* SecurityManager (if active).* @param ctor the constructor to make accessible* @see java.lang.reflect.Constructor#setAccessible*/public static void makeAccessible(Constructor<?> ctor) {if ((!Modifier.isPublic(ctor.getModifiers()) ||!Modifier.isPublic(ctor.getDeclaringClass().getModifiers())) && !ctor.isAccessible()) {ctor.setAccessible(true);}}
……

……
private class AutowiredFieldElement extends InjectionMetadata.InjectedElement {private final boolean required;private volatile boolean cached = false;private volatile Object cachedFieldValue;public AutowiredFieldElement(Field field, boolean required) {super(field, null);this.required = required;}@Overrideprotected void inject(Object bean, String beanName, PropertyValues pvs) throws Throwable {Field field = (Field) this.member;try {Object value;if (this.cached) {value = resolvedCachedArgument(beanName, this.cachedFieldValue);}else {DependencyDescriptor desc = new DependencyDescriptor(field, this.required);desc.setContainingClass(bean.getClass());Set<String> autowiredBeanNames = new LinkedHashSet<String>(1);TypeConverter typeConverter = beanFactory.getTypeConverter();value = beanFactory.resolveDependency(desc, beanName, autowiredBeanNames, typeConverter);synchronized (this) {if (!this.cached) {if (value != null || this.required) {this.cachedFieldValue = desc;registerDependentBeans(beanName, autowiredBeanNames);if (autowiredBeanNames.size() == 1) {String autowiredBeanName = autowiredBeanNames.iterator().next();if (beanFactory.containsBean(autowiredBeanName)) {if (beanFactory.isTypeMatch(autowiredBeanName, field.getType())) {this.cachedFieldValue = new RuntimeBeanReference(autowiredBeanName);}}}}else {this.cachedFieldValue = null;}this.cached = true;}}}if (value != null) {//设置字段访问权限为可访问
                    ReflectionUtils.makeAccessible(field);//对字段进行赋值
                    field.set(bean, value);}}catch (Throwable ex) {throw new BeanCreationException("Could not autowire field: " + field, ex);}}}
……