java7中的List中使用filter过滤出符合特定条件的元素List

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1.定义一个 ListFilterStrategy 接口，实现过滤条件封装

/**
 * @Auther: wuzheng
 * @Date: 2018/12/5 14:01
 * @Description:  定义List过滤基本方法
 */
public interface ListFilterStrategy {

    public boolean contain(T t);
}

2.ListUtils 实现

/**
 * @Auther: wuzheng
 * @Date: 2018/12/5 13:56
 * @Description: List工具类，存放一些比较常用的公共部分功能
 */
public final class ListUtils {
    /**
     * 根据条件对List进行过滤
     * @param list
     * @param strategy
     * @param 
     * @return
     */
    public static  List filter(List list, ListFilterStrategy strategy) {
        List rList = new ArrayList<>();
        if(CollectionUtils.isNotEmpty(list)){
            for (int i = 0; i < list.size(); i++) {
                T t =  list.get(i);
                if (strategy.contain(t)){
                    rList.add(t);
                }
            }
        }
        ((ArrayList) rList).trimToSize();//释放申请的多余的空间
        return rList;
    }

    public static void main(String[] args) {
        List list = new ArrayList<>();
        for (int i = 0; i <10; i++) {
            list.add(i);
        }
        final List alist = Arrays.asList(1, 2, 3);
        List rList=filter(list, new ListFilterStrategy() {
            @Override
            public boolean contain(Integer integer) {
                return alist.contains(integer);
            }
        });
        System.out.println(rList.size());
    }

 

转载于:https://my.oschina.net/codeTec/blog/2978944