使用泛型解决之前的问题

package fanxing;

/*
* 使用泛型解决之前的问题
*/

import java.util.ArrayList;
import java.util.Iterator;
import java.util.LinkedList;

public class TestGeneric02 {
public static void main(String[] args) {

LinkedList<Integer> list = new LinkedList<>();
ArrayList<String> list2 = new ArrayList<>();
LinkedList<Integer> list3 = new LinkedList<>();
// 如果使用泛型，不能向集合中添加泛型类型以外的类型
list.add(11);
list2.add("123");
list.add(333);
System.out.println(list);
System.out.println(list2);
System.out.println(list3);
Iterator<Integer> iterator = list.iterator();
while (iterator.hasNext()) {
iterator.next();
System.out.println("iterator" + iterator);
System.out.println("0");
}
Iterator<String> iterator2 = list2.iterator();
while (iterator2.hasNext()) {
iterator2.next();
System.out.println("iterator2" + iterator2);
System.out.println("0");
}
Iterator<Integer> iterator3 = list3.iterator();
while (iterator3.hasNext()) {
iterator3.next();
System.out.println("iterator3" + iterator3);
System.out.println("0");
}
}
}