static void testListIteratorAdd(){

        LinkedList<String> strList = new LinkedList<String>();

        strList.add("1");

        strList.add("2");

        strList.add("3");

        print("init content:");

        printCollection(strList);

        ListIterator<String> it = strList.listIterator();

        it.next();

        it.add("1.1");

        it.add("1.2");

        print("after insert 2 item");

        printCollection(strList);

    }

init content:

collection content:

    item:1

    item:2

    item:3

after insert 2 item

collection content:

    item:1

    item:1.1

    item:1.2

    item:2

    item:3

static void testListIteratorRemove(){

        LinkedList<String> strList = new LinkedList<String>();

        strList.add("1");

        strList.add("2");

        strList.add("3");

        print("init content:");

        printCollection(strList);

        ListIterator<String> it = strList.listIterator();

        it.next();

        it.remove();//ok        

        print("after remove 1 item");

        printCollection(strList);

        it.remove();//error

        print("after remove 2 item");

        printCollection(strList);

    }

init content:

collection content:

    item:1

    item:2

    item:3

after remove 1 item

collection content:

    item:2

    item:3

Exception in thread "main" java.lang.IllegalStateException

    at java.util.LinkedList$ListItr.remove(LinkedList.java:923)

    at me.ygc.javabasic.learnJava.LearnCollection.testListIteratorRemove(LearnCollection.java:33)

    at me.ygc.javabasic.learnJava.LearnCollection.main(LearnCollection.java:15)