java 排序

 list为对象的集合

//按照id正序排列  
Collections.sort(list, new Comparator<Product>() {  
    public int compare(Product arg0, Product arg1) {  
        return arg0.getgetId().compareTo(arg1.getId());  
    }  
});  



进化版
//按照开始时间排序  
Collections.sort(list, (arg0, arg1) -> arg0.getId.compareTo(arg1.getId));  



进化版
Collections.sort(list, Comparator.comparing(Product::getId));  

或

list.sort((o1, o2) -> o2.getId().compareTo(o1.getId()));