java多态反照机制例子

2012-10-06

java多态反射机制例子package?duotai????class?Customer{??????@SuppressWarnings(unused)??????privat

java多态反射机制例子

package?duotai;????
class?Customer{??????@SuppressWarnings("unused")??
????private?String?account;??????@SuppressWarnings("unused")??
????private?String?password;??????//有两个函数名称一样，但是系统可以接受，这叫做函数重载（静态多态性）??
????//一个函数呈现为多种状态，系统能够根据参数来决定调用谁??????//三种情况：参数个数不同，参数个数相同类型不同，个数类型相同出现的顺序不同??
????//静态是指：虽然函数名只有一个，但是要写代码要写多个??????public?Customer()??
????{??????????System.out.println("构造函数1");??
????}????????
????public?Customer(String?account,?String?password)?{??????????System.out.println("构造函数2");??
????????this.account=account;??????????this.password=password;??
????}??}??
????
public?class?CustomerTest?{??????public?static?void?main(String[]?args)?{??
????????@SuppressWarnings("unused")??????????Customer?cus1?=?new?Customer();//调用构造函数??
????????@SuppressWarnings("unused")??????????Customer?cus2?=?new?Customer("3213","1213");//调用构造函数??
????}????
}??

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package?duotai;????
//模块1调用一个对话框，让对话框显示出来????
class?Module1?{??????private?Dialog?dialog;??
??????public?Module1(Dialog?dialog)?{??
????????this.dialog?=?dialog;??????}??
??????????public?void?callDialog(){??
????????dialog.show();??????}??
??}??
??abstract?class?Dialog{??
????public?abstract?void?show();??}??
class?Dialog1?extends?Dialog?{??????public?void?show()?{??
????????System.out.println("对话框1显示");??????}??
}??//客户对Dialog1不满意想自己开发一个Dialog2，被Module1调用，不能改变Module1原代码??
??class?Dialog2?extends?Dialog{??
????public?void?show()?{??????????System.out.println("对话框2显示");??
????}??}??
????
public?class?DaliogTest?{????
????public?static?void?main(String[]?args)?{????????????
????????Dialog1?dia?=?new?Dialog1();??????????Module1?mod1?=?new?Module1(dia);??
??????????????????mod1.callDialog();??
????}????
}??

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package?duotai;????
//动态多态性一般在继承时使用??abstract?class?Person{??
????public?abstract?void?printInfo();??}??
??class?Student?extends?Person{??
????public?void?printInfo()?{??????????System.out.println("学生打印");??
????}??}??
??class?Teacher?extends?Person{??
????public?void?printInfo()?{??????????System.out.println("老师打印");??
????}??}??
??public?class?StudentTest?{??
/*??public?static?void?print(Student?stu)?{?????????stu.printInfo();?
????}??
????public?static?void?print(Teacher?tea)?{?????????tea.printInfo();?
????}*/????public?static?void??print(Person?p)?{//父类的引用可以指向子类对象??
????p.printInfo();??}??
????public?static?void?main(String[]?args)?{??????????print(new?Student());???
????}????
}??

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package?fanshe;????
??public?class?Customer?{??
????private?String?account;??????private?String?password;??
??????public?Customer()?{??
????????System.out.println("构造函数1");??????}??
??????public?Customer(String?account,?String?password)?{??
????????System.out.println("构造函数2");??????????this.account?=?account;??
????????this.password?=?password;??????}??
??????public?void?printInfo()?{??
????????System.out.println("账号："?+?account?+?"密码"?+?password);??????}??
}??

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package?fanshe;????
import?java.lang.reflect.Constructor;??import?java.lang.reflect.Method;??
??public?class?Test1?{??
????@SuppressWarnings("unchecked")??????public?static?void?main(String[]?args)?throws?Exception?{??
??????????String?className?=?"fanshe.Customer";??
????????//?className?cus?=?new?className();??????????//?得到类的信息??
????????Class?c?=?Class.forName(className);????
????????//?得到构造函数，就可以生成一个对象??????????Constructor[]?cons?=?c.getConstructors();??
????????for?(int?i?=?0;?i?<?cons.length;?i++)?{??????????????String?str?=?cons[i].getName();??
????????????System.out.println("名字："?+?str);????????????????
????????????Class[]?params?=?cons[i].getParameterTypes();//?得到参数类型??????????????for?(int?j?=?0;?j?<?params.length;?j++)?{??
????????????????String?name?=?params[j].getName();??????????????????System.out.println(name);??
????????????}??????????}??
????????//得到里面的成员函数(包括继承过来的)，就可以调用成员函数??????????Method[]?met?=?c.getMethods();??
????????for?(int?i?=?0;?i?<?met.length;?i++)?{??????????????String?str?=?met[i].getName();??
????????????System.out.println("名字："?+?str);????????????????
????????????Class[]?params?=?met[i].getParameterTypes();//?得到参数类型??????????????for?(int?j?=?0;?j?<?params.length;?j++)?{??
????????????????String?name?=?params[j].getName();??????????????????System.out.println(name);??
????????????}??????????}??
????}????
}??

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package?fanshe;????
import?java.lang.reflect.Constructor;??import?java.lang.reflect.Method;??
??public?class?Test2?{??
????@SuppressWarnings("unchecked")??????public?static?void?main(String[]?args)?throws?Exception?{??
????????/*??????????*?反射为配置文件改变模块行为提供了可能?
?????????*/??????????String?className?=?"fanshe.Customer";??
????????Class?c?=?Class.forName(className);??????????//c.newInstance();表示调用不带参数的构造函数??
????????//?生成一个对象：用构造函数??????????Constructor?con1?=?c.getConstructor(new?Class[]?{Class.forName("java.lang.String"),Class.forName("java.lang.String")?});??
????????//Constructor?con1?=?c.getConstructor(new?Class[]?{});//?得到不带参数的构造函数????????
????????//?生成对象??????????Object?obj?=?con1.newInstance(new?Object[]?{"222","111"});??
????????//Object?obj?=?con1.newInstance(new?Object[]?{});//?表示不传入参数??????????//怎样调用obj里面的方法??
????????Method?met?=?c.getMethod("printInfo",?new?Class[]{});//得到方法??????????met.invoke(obj,?new?Object[]{});//调用??
??????????????????/*Customer?cus?=?new?Customer("222","111");?
????????cus.printInfo();*/????????????
????}????
}????
??/*public?class?Test2?{?
????public?static?void?main(String[]?args)?throws?Exception?{?????????String?className?=?"fanshe.Customer";?
????????Class?c?=?Class.forName(className);?????????Constructor?con1?=?c.getConstructor(new?Class[]?{Class.forName("java.lang.String"),Class.forName("java.lang.String")?});?
????????Object?obj?=?con1.newInstance(new?Object[]?{"222","111"});?????????Method?met?=?c.getMethod("printInfo",?new?Class[]{});?
????????met.invoke(obj,?new?Object[]{});?????}?
}*/?

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java多态反照机制例子