java - 如何比较java中至少一个属性不同的相似对象的两个数组列表? [英] How to compare two array lists for similar objects which differ in at least one property in java?
问题描述
我有两个数组列表.每个都有用户类型的对象列表.
I have two array list. Each has list of Objects of type User.
User 类如下所示
public class User {
private long id;
private String empCode;
private String firstname;
private String lastname;
private String email;
public User( String firstname, String lastname, String empCode, String email) {
super();
this.empCode = empCode;
this.firstname = firstname;
this.lastname = lastname;
this.email = email;
}
// getters and setters
}
import java.util.ArrayList;
import java.util.List;
public class FindSimilarUsersWithAtLeastOneDifferentProperty {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
List<User> list1 = new ArrayList<User>();
list1.add(new User("F11", "L1", "EMP01", "u1@test.com"));
list1.add(new User("F2", "L2", "EMP02", "u222@test.com"));
list1.add(new User("F3", "L3", "EMP03", "u3@test.com"));
list1.add(new User("F4", "L4", "EMP04", "u4@test.com"));
list1.add(new User("F5", "L5", "EMP05", "u5@test.com"));
list1.add(new User("F9", "L9", "EMP09", "u9@test.com"));
list1.add(new User("F10", "L10", "EMP10", "u10@test.com"));
List<User> list2 = new ArrayList<User>();
list2.add(new User("F1", "L1", "EMP01", "u1@test.com"));
list2.add(new User("F2", "L2", "EMP02", "u2@test.com"));
list2.add(new User("F6", "L6", "EMP06", "u6@test.com"));
list2.add(new User("F7", "L7", "EMP07", "u7@test.com"));
list2.add(new User("F8", "L8", "EMP08", "u8@test.com"));
list2.add(new User("F9", "L9", "EMP09", "u9@test.com"));
list2.add(new User("F100", "L100", "EMP10", "u100@test.com"));
List<User> resultList = new ArrayList<User>();
// this list should contain following users
// EMP01 (common in both list but differs in firstname)
// EMP02 (common in both list but differs in email)
// EMP10 (common in both list but differs in firstname, lastname and email)
}
}
如果看到示例代码，两个列表有四个用户，emp 代码 EMP01、EMP02、EMP09 和 EMP10 共同.
If you see the sample code, the two lists have four users with emp code EMP01, EMP02, EMP09 and EMP10 common.
所以，我们只需要比较这四个用户的属性即可.
So, we only need to compare the properties of these four users.
如果任何用户至少有一个不同的属性，则应将其添加到结果列表中.
If any of the users have at least one different property it should be added in the result list.
请告诉我该怎么做?
推荐答案
我认为这是你应该做的 -
I think this what you should do -
for(User user1 : list1) {
for(User user2 : list2) {
if(user1.getEmpCode().equals(user2.getEmpCode())) {
if(!user1.getFirstName().equals(user2.getFirstName()) ||
!user1.getLastName().equals(user2.getLastName()) ||
!user1.getEmail().equals(user2.getEmail())) {
resultList.add(user1);
}
}
}
}
User 重写 equal 和 hashCode 仅用于此目的可能没有意义.它们应该以在域方面更有意义的方式被覆盖.
It might not make sense for the User to override equal and hashCode only to serve this purpose. They should be overriden in the way in which it makes more sense domain-wise.
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