Java仿造C#写了个LinqUtil，使用Lambda和泛型，对对象集合过滤filter筛选和取属性map，供大家参考使用

package xxx;

import java.util.List;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.stream.Collectors;

public class LinqUtil {
    
    public static  T first(List list) {
        return list.get(0);
    }

    
    public static  List filter(List items, Predicate filterexpression) {
        return items.stream().filter(filterexpression).collect(Collectors.toList());
    }

    
    public static  T filterOne(List items, Predicate filterexpression) {
        return filter(items, filterexpression).get(0);
    }

    
    public static  List map(List items, Function mapexpression) {
        return items.stream().map(mapexpression).collect(Collectors.toList());
    }

    
    public static  R mapOne(List items, Function mapexpression) {
        return map(items, mapexpression).get(0);
    }
}