如何比较在Java中至少一个属性不同的相似对象的两个数组列表？

Question

我有两个数组列表。每个对象都有用户类型的对象列表。

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", "[e-mail]"));
        list1.add(new User("F2", "L2", "EMP02", "[e-mail]"));
        list1.add(new User("F3", "L3", "EMP03", "[e-mail]"));
        list1.add(new User("F4", "L4", "EMP04", "[e-mail]"));
        list1.add(new User("F5", "L5", "EMP05", "[e-mail]"));
        list1.add(new User("F9", "L9", "EMP09", "[e-mail]"));
        list1.add(new User("F10", "L10", "EMP10", "[e-mail]"));

        List<User> list2 = new ArrayList<User>();

        list2.add(new User("F1", "L1", "EMP01", "[e-mail]"));
        list2.add(new User("F2", "L2", "EMP02", "[e-mail]"));
        list2.add(new User("F6", "L6", "EMP06", "[e-mail]"));
        list2.add(new User("F7", "L7", "EMP07", "[e-mail]"));
        list2.add(new User("F8", "L8", "EMP08", "[e-mail]"));
        list2.add(new User("F9", "L9", "EMP09", "[e-mail]"));
        list2.add(new User("F100", "L100", "EMP10", "[e-mail]"));

        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)


    }

}

如果您看到示例代码，则这两个列表有四个用户，它们的emp代码共同为EMP01，EMP02，EMP09和EMP10。

因此，我们只需要比较这四个用户的属性。

如果任何用户具有至少一个不同的属性，则应将其添加到结果列表中。

请告知我该如何处理？

Answer 1

我认为这是您应该做的-

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覆盖equal并hashCode仅出于此目的可能没有意义。应该以更有意义的方式覆盖它们。