Map<String, String> mapServlet = new HashMap<String, String>();
　　　　　　  System.out.println("迭代方法一");
            for( Object key:mapServlet.keySet()){
                System.out.println( key );
                System.out.println(mapServlet.get(key));
            }
            System.out.println("迭代方法二");
            for( Object value: mapServlet.values()){
                System.out.println(value);
            }
            System.out.println("迭代方法三");
            for(Iterator iterator = mapServlet.entrySet().iterator();iterator.hasNext();){
                Object keyObject = iterator.next();
                System.out.println(keyObject);
            }
            System.out.println("迭代方法四");
            for(Iterator iterator = mapServlet.entrySet().iterator();iterator.hasNext();){
                Map.Entry entry = (Entry)iterator.next();
                System.out.println(entry.getKey());
                System.out.println(entry.getValue());
            }