java的iterator 遍历 list 和 map

1 . java通过 iterator 遍历list

// 导入 apache的 commons-logging-xx.jar
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
public class Print
{
      Log log = LogFactory.getLog(HelloWorld.class);

      List list = new ArrayList();
      list.add("aa");
      list.add("bb");
      list.add("cc");
      list.add(120);

     
      for( Iterator<Object> item =list.iterator();item.hasNext();) {
            Object temp = item.next();
              log.info(temp);
       }
}

2 . 遍历 map

HashMap<Integer, String> map=new HashMap<>();
        map.put(100, "aa");
        map.put(400, "bb");
        map.put(500, "cc");
        Set<Integer> keySet=map.keySet();
        log.error(keySet.toString());
        for(Iterator<Integer> items=keySet.iterator();items.hasNext();){
            Integer key=items.next();
            log.info(key+"-------"+map.get(key));
        }