将对象数组添加到数组列表中，并根据一个属性值与其他数组列表进行比较并过滤结果

Question

将对象数组添加到数组列表中，并根据一个属性值与其他数组列表进行比较并过滤结果。

我有一个对象 personDetails 和 departmentDetails 的数组。

package com.education;

import java.util.*;

 public class educationMain {

 public static void main(String[] args) {
    
    List<person> list=new ArrayList<person>();  
    person l1 = new person(1,"Samual",100,"Sales","Business");
    person l2 = new person(2,"Alex",100,"Sales","Business");
    person l3 = new person(3,"Bob",101,"Engineering","Technology");
    person l4 = new person(4,"Michel",101,"Engineering","Technology");
    person l5 = new person(5,"Ryan",102,"PR","Services");
    person l6 = new person(6,"Horward",103,"Leadership","Managmnet");
    person l7 = new person(7,"Cyna",104,"HR","Human Resource");
    list.add(l1);  
    list.add(l2);  
    list.add(l3); 
    list.add(l4);  
    list.add(l5);  
    list.add(l6); 
    list.add(l7); 
    
     for(person b:list){  
            System.out.println(b.personId+" "+b.name+" "+b.deptCode+" "+b.parentDept+" "+b.deptName);  
     }  
     
     
     List<department> depList = new ArrayList<department>();
     
     department d1 = new department(100, "Sales","Business");
     department d2 = new department(101, "Engineering","Technology");
     department d3 = new department(102, "PR","Services");
     depList.add(d1);  
     depList.add(d2);  
     depList.add(d3); 

     for(department b:depList){  
            System.out.println(b.deptCode+" "+b.parentDept+" "+b.deptName);  
     }
}

}

所以上面的代码工作正常并且显示正确。

我的人物类

包 com.education;

public class person {
    public int personId;
    public String name;
    private int deptCode;
    private String parentDept;
    private String deptName;
    
    public person(int personId, String name, int deptCode, String parentDept, String deptName) {
        super();
        this.personId = personId;
        this.name = name;
        this.deptCode = deptCode;
        this.parentDept = parentDept;
        this.deptName = deptName;
    }
    
    public void display(){
         System.out.println(" " + personId + " " +name + " " + deptCode+ " " + parentDept + " "+deptName);
         System.out.println();
    }
    
}

我的系类

public class department {
    
    private int deptCode;
    private String parentDept;
    private String deptName;
    public department(int deptCode, String parentDept, String deptName) {
        super();
        this.deptCode = deptCode;
        this.parentDept = parentDept;
        this.deptName = deptName;
    }
    
    public void dispalyDepartment() {
        System.out.println(" "+deptCode+" "+parentDept+" "+deptName);
    }

}

现在我的目标是将 personDetails 和 departmentDetails 放入 arraylist 并进行比较，然后根据部门代码找出差异。

这是我的逻辑：工作正常。

List<person> listC = new ArrayList<person>();
         
         
         for(person p : list) {
             boolean  flag = false;
             for (department d:depList) {
                 if(p.deptCode == d.deptCode) {
                     flag = false;
                     break;
                 }else {
                     flag = true;
                 }
             }
             if(flag == true) {
                 listC.add(p);
             }
         }

o/p 应该是这样的

    (6,"Horward",103,"Leadership","Managmnet");
    (7,"Cyna",104,"HR","Human Resource");
    

因为 deptCode : 103 和 104 不存在。

有人可以帮我吗？我可以使用任何其他收集技术吗？

Answer 1

试试这个。

    Set<Integer> deptCodes = Arrays.stream(departmentDetails)
        .map(department -> department.deptCode)
        .collect(Collectors.toSet());
    List<person> persons = Arrays.stream(personDetails)
        .filter(person -> !deptCodes.contains(person.deptCode))
        .collect(Collectors.toList());
    persons.forEach(person -> person.display());

输出：

 6 Horward 103 Leadership Managmnet

 7 Cyna 104 HR Human Resource