Map的循环取键和值

  List list = new ArrayList(); Map mp=new HashMap(); mp.put("a", "aaaaaaa"); mp.put("b", "bbbbbbb"); mp.put("c", "cccccccccc"); mp.put("d", "ddddddd"); list.add(mp); long begin=System.currentTimeMillis(); for (int i = 0; i <list.size(); i++) { HashMap pp=(HashMap)list.get(i); Iterator itr = pp.entrySet().iterator(); while(itr.hasNext()){ Map.Entry entry=(Entry) itr.next(); System.out.println(entry.getKey()+"--"+entry.getValue()); } } long end=System.currentTimeMillis(); System.out.println(end-begin);