java stream filter的疑惑

Question

实际编码,qc遇到的问题

package test;

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

public class normalTest {

    public static boolean compareStr(String a, String b) {
        return a.compareTo(b) >= 0;
    }

    public static void main(String[] args) {
        List<Custom> strList = new ArrayList<>();
        strList.add(new Custom("a"));
        strList.add(new Custom("m"));
        strList.add(new Custom("d"));
        strList.add(new Custom("y"));
        strList.add(new Custom("e"));
        strList.add(new Custom("s"));
        strList.add(new Custom("!"));
        strList = strList.stream().filter(o -> compareStr("g", o.getField())).collect(Collectors.toList());
        strList.forEach(o->o.setField("#"));
        System.out.println(strList);
    }

    @Data
    static class Custom {
        Custom (String str) {
            field = str;
        }
        public String field;
    }
}

可以用stream()先filter后再collect
得到新的list再foreach来进行修改

能不能一次循环解决,也就是filter的同时做foreach的操作

Answer 1

strList = strList.stream().filter(o -> compareStr("g", o.getField())).peek(o -> o.setField("#") ).collect(Collectors.toList());