Java8中使用stream将字符串集合转换成数字集合

package com.zhchong.streams;

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

public class StreamDemo2 {

	public static void main(String[] args) {
		List l1 = new ArrayList();
		l1.add("1");
		l1.add("2");
		l1.add("3");
		System.out.println(l1);
		List l2 = l1.stream().map(s -> Long.valueOf(s)).collect(Collectors.toList());
		System.out.println(l2);
	}
	
}