用TreeMap對key排序
//按年份，取出最近10項 List<StatisticalData> projectYear = statisticalInfo.getProjectYear(); Map<String,String> treeMap = new TreeMap<String,String>(); Map<String,String> hashMap = new HashMap<String,String>(); for (StatisticalData statisticalData : projectYear) { treeMap.put(statisticalData.getName(),statisticalData.getValue()); hashMap.put(statisticalData.getName(),statisticalData.getValue()); } //排序treeMap:{2010-03=3, 2010-04=1, 2010-05=3, 2010-06=1, 2010-08=1, 2010-09=2, 2010-11=1, 2010-12=2, 2011-01=4, 2011-03=2, 2011-04=7, 2011-05=1, 2011-07=1, 2011-10=3, 2011-11=1, 2011-12=3, 2012-02=1, 2012-03=2, 2012-04=1, 2012-05=1, 2012-07=3, 2012-08=6, 2012-09=2, 2012-10=1, 2012-12=2, 2013-01=1, 2013-03=6, 2013-04=1, 2013-05=6, 2013-06=5, 2013-07=2}
//無序hashMap:{2012-02=1, 2012-03=2, 2012-04=1, 2012-05=1, 2012-07=3, 2012-08=6, 2012-09=2, 2010-11=1, 2010-12=2, 2011-12=3, 2011-10=3, 2011-11=1, 2013-01=1, 2011-07=1, 2011-05=1, 2011-04=7, 2011-03=2, 2011-01=4, 2010-06=1, 2010-05=3, 2010-04=1, 2010-03=3, 2012-12=2, 2013-07=2, 2012-10=1, 2013-03=6, 2013-04=1, 2013-05=6, 2010-09=2, 2010-08=1, 2013-06=5}