Java中Map的排序

个人认为主要还是注意ArrayList( Collection c) 这个构造方法，然后对这个List排序即可！

public static void main(String[] args) {
		Map map = new HashMap();
		map.put("First", 20);
		map.put("Second", 10);
		map.put("Third", 30); 		
		
		List arrayList = new ArrayList(map.entrySet());
//注意构造函数	
         	//排序前
		for(Iterator it = arrayList.iterator();it.hasNext();){
			Map.Entry entry = (Map.Entry)it.next();
			System.out.print(entry.getKey()+":"+entry.getValue()+"  ");
		}
		Collections.sort(arrayList, new TariffComparator.TariffMapComparator());
		System.out.println();
		//排序后
		for(Iterator it = arrayList.iterator();it.hasNext();){
			Map.Entry entry = (Map.Entry)it.next();
			System.out.println(entry.getKey()+":"+entry.getValue());
		}
	}

 排序方法：

public class TariffComparator {
	
	public static class TariffMapComparator implements Comparator{

		public int compare(Object o1, Object o2) {
			Map.Entry obj1 = (Map.Entry)o1;
			Map.Entry obj2 = (Map.Entry)o2;			
			return obj1.getValue().toString().compareTo(obj2.getValue().toString());
		}
	}
}

 结果：

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