public class Student { 
    private String name;//姓名
    private Integer age;//年齡
    private int sex;//性別
    private String professional;//專(zhuān)業(yè) 
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Integer getAge() {
        return age;
    }
    public void setAge(Integer age) {
        this.age = age;
    }
    public int getSex() {
        return sex;
    }
    public void setSex(int sex) {
        this.sex = sex;
    }
    public String getProfessional() {
        return professional;
    }
    public void setProfessional(String professional) {
        this.professional = professional;
    }
    public Student(String name, Integer age, int sex, String professional) {
        super();
        this.name = name;
        this.age = age;
        this.sex = sex;
        this.professional = professional;
    }

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors; 
public class StreamTest { 

    public static void main(String[] args) {
        List<Student> allList = new ArrayList<Student>(); 
        Student st1 = new Student("小王",26,1,"計(jì)算機(jī)");
        allList.add(st1);
        Student st2 = new Student("小張",21,1,"電氣");
        allList.add(st2);
        Student st3 = new Student("小紅",22,1,"人文");
        allList.add(st3);
        Student st4 = new Student("小李",23,1,"計(jì)算機(jī)");
        allList.add(st4);
 
        System.out.println("**************************目的：只取專(zhuān)業(yè)為計(jì)算機(jī)行業(yè)的集合*************************");
//        allList = allList.stream().filter(Student -> Student.getProfessional().equals("計(jì)算機(jī)")).collect(Collectors.toList());
//        allList.forEach(Student -> {
//            System.out.println(Student.getName());
//        });
        System.out.println("**************************目的：取專(zhuān)業(yè)為計(jì)算機(jī)和人文專(zhuān)業(yè)的集合*************************");
        List<String> str=new ArrayList<>();
        str.add("計(jì)算機(jī)");
        str.add("人文");
        allList = allList.stream().filter(Student -> str.contains(Student.getProfessional())).collect(Collectors.toList());
        allList.forEach(Student -> {
            System.out.println(Student.getName());
        }); 
    }