删除集合中的元素的实验

package yingwu.test.all;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/*
* 为解决www.blogjava.net/chengang关于删除集合中的元素方法而做的试验
* 结论:operate()方法本身没有问题,可以删除掉集合中的数据,但要注意顺序
* 这个函数本身执行是不会 报错的.

* 过程1:
* ........
* Iterator it=list.iterator();
* operate(list);
* while(it.hasNext()){
* System.out.println(it.next());
* }
* ...............................
* 这样确实会报错:
* Exception in thread "main" java.util.ConcurrentModificationException
* at java.util.AbstractList$Itr.checkForComodification(Unknown Source)
* at java.util.AbstractList$Itr.next(Unknown Source)
* at yingwu.test.all.DeleteFromList.main(DeleteFromList.java:30)

* .....................................
* 是因为前面的Iteater引用了这个元素,但被删了.
* 正确的过程应该是:2
* 过程2:
* ..........
* operate(list);
* Iterator it=list.iterator();
* while(it.hasNext()){
* System.out.println(it.next());
* }

* 2008-03-27 13:55 | yingwu

*/
public class DeleteFromList {
public static void main(String[] args){
List l=new ArrayList();
l.add("123");
l.add("456");
operate(l,"123");
Iterator it=l.iterator();
/*while(it.hasNext()){
Object temp=it.next();
String s=(String)temp;
if(temp==s){
System.out.print(true);
}
if(((String)temp).equals("123")){
l.remove(s);
//it.remove();
}

}*/


//it=l.iterator();
while(it.hasNext()){
System.out.println(it.next());
}

}
public static void operate(List list,String delete){
        for (Iterator it = list.iterator(); it.hasNext();) {
            String str =  (String)it.next();
            if (str.equals(delete)){
                list.remove(str);
            }
        }
    }


}