java映射

虚拟机通过得到类的字节码文件，从而创建对象。在java代码中可用Class类中的方法进行实现，

 1 package javase;
 2 
 3 import java.lang.reflect.Constructor;
 4 import java.lang.reflect.InvocationTargetException;
 5 
 6 public class ReflextDemo {
 7     
 8     public static void method2() throws ClassNotFoundException, NoSuchMethodException, SecurityException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
 9         
10         String name = "test.Person";//把类名的路径存到字符串
11         Class clazz = Class.forName(name);//通过路径拿到字节码文件，创建对象
12         Constructor<Person> con = clazz.getConstructor(String.class,int.class);//获取构造器
13         Object obj = con.newInstance("小强",10);//创建实例
14         
15     }
16 
17     public static void method1() throws ClassNotFoundException, InstantiationException, IllegalAccessException {
18         
19         String name = "test.Person";//把类名的路径存到字符串
20         Class clazz = Class.forName(name);//通过路径拿到字节码文件，创建对象
21         Object obj = clazz.newInstance();//创建实例
22         
23     }
24     
25     public static void main(String[] args) throws ClassNotFoundException, NoSuchMethodException, SecurityException, InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
26 
27         method2();
28         
29     }
30 
31 }