Question

根据属性，我很难 整理我的对象 。

我有这个患者对象列表，我想根据他们的姓氏进行排序，但根本不对它们进行排序。你能告诉我我做错了什么吗？

以下是一些相关的代码。

Patient.java

import java.util.Comparator;

public class Patient implements Comparable<Patient> {
    String fname, lname, mname, ID;

    public static class OrderByLastName implements Comparator<Patient> {

        @Override
        public int compare(Patient p1, Patient p2) {
            return p1.lname.compareTo(p2.lname);
        }
    }

    public static class OrderByID implements Comparator<Patient> {

        @Override
        public int compare(Patient p1, Patient p2) {
            return p1.ID.compareTo(p2.ID);
        }
    }

    @Override
    public int compareTo(Patient another) {
        // TODO Auto-generated method stub
        return 0;
    }
}

MainActivity.java

public class PatientList extends ActionBarActivity {

String[] newFName = {"Mark","Andy","Bryan"};
String[] newLName = {"Uy","Igy","Nator"};
String[] newMName = {"Wi","Menos","Pat"};
String[] newID = {"3","5","1"};
ArrayList<Patient> patientList;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    createPatientList();
    sortPatient(1);

}

private void createPatientList() {
    patientList = new ArrayList<Patient>();
    for (int i = 0; i < newFName.length; i++) {
        Patient patient = new Patient();
        patient.lname = newLName[i];
        patient.fname = newFName[i];
        patient.mname = newMName[i];
        patient.ID = newID[i];
        patientList.add(patient);
    }
}

private void sortPatient(int order){
    switch (order) {
        case 1:
            Collections.sort(patientList, new Patient.OrderByLastName());
            break;
        case 2:
            Collections.sort(patientList, new Patient.OrderByID());
            break;
        default:
            break;
        }
}
}

Answer 1

据我所知，你的代码应该可行，我怀疑单元测试会证明这一点。如果您的问题是您无法看到更新，那么您的视图更新逻辑可能有问题。

Answer 2

Philip，我刚刚复制了你的代码并将其粘贴到一个java项目中。下面的源代码以及输出的屏幕截图。我没有对Patient课程做任何改动;只是复制并粘贴到我的项目中。

Test.java：

import java.util.ArrayList;
import java.util.Collections;

public class Test {

    static String[] newFName = { "Mark", "Andy", "Bryan" };
    static String[] newLName = { "Uy", "Igy", "Nator" };
    static String[] newMName = { "Wi", "Menos", "Pat" };
    static String[] newID = { "3", "5", "1" };
    static ArrayList<Patient> patientList;

    public static void main(String[] args) {

        createPatientList();

        System.out.println("Before: ");
        for (Patient p : patientList) {
            System.out.println(p.lname);
        }

        sortPatient(1);

        System.out.println("\nAfter: ");
        for (Patient p : patientList) {
            System.out.println(p.lname);
        }
    }

    private static void createPatientList() {
        patientList = new ArrayList<Patient>();
        for (int i = 0; i < newFName.length; i++) {
            Patient patient = new Patient();
            patient.lname = newLName[i];
            patient.fname = newFName[i];
            patient.mname = newMName[i];
            patient.ID = newID[i];
            patientList.add(patient);
        }
    }

    private static void sortPatient(int order) {
        switch (order) {
        case 1:
            Collections.sort(patientList, new Patient.OrderByLastName());
            break;
        case 2:
            Collections.sort(patientList, new Patient.OrderByID());
            break;
        default:
            break;
        }
    }
}

屏幕截图：

screen shot

可比较不排序对象

2 个答案: