反射：利用泛型在编译过程中被抹去

package cn.itcast.day1;

import java.util.ArrayList;

public class GenericTest {

/**
* @param args
*/
public static void main(String[] args)throws Exception{
// TODO Auto-generated method stub
ArrayList<Integer> collection1=new ArrayList<Integer>();
collection1.add(1);
collection1.add(3);
collection1.add(9);
collection1.getClass().getMethod("add",Object.class).invoke(collection1, "ligang");
System.out.println(collection1.get(3));
}

}