我想要对包含属性名称和类(class)的学生对象列表进行排序,以便根据名称进行排序,如果两个名称相同,那么它应该考虑类(class)进行排序...我可以单独进行,但想要一个列出...请帮忙...
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package studentlist;
import java.util.*;
/**
*
* @author Administrator
*/
public class StudentList {
/**
* @param args the command line arguments
*/
String name, course;
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getCourse() {
return course;
}
public void setCourse(String course) {
this.course = course;
}
public StudentList(String name, String course) {
this.name = name;
this.course = course;
}
public static void main(String[] args) {
// TODO code application logic here
List<StudentList> list = new ArrayList<StudentList>();
list.add(new StudentList("Shaggy", "mca"));
list.add(new StudentList("Roger", "mba"));
list.add(new StudentList("Roger", "bba"));
list.add(new StudentList("Tommy", "ca"));
list.add(new StudentList("Tammy", "bca"));
Collections.sort(list, new NameComparator());
Iterator ir = list.iterator();
while (ir.hasNext()) {
StudentList s = (StudentList) ir.next();
System.out.println(s.name + " " + s.course);
}
System.out.println("\n\n\n ");
Collections.sort(list, new CourseComparator());
Iterator ir1 = list.iterator();
while (ir1.hasNext()) {
StudentList s = (StudentList) ir1.next();
System.out.println(s.name + " " + s.course);
}
}
}
class NameComparator implements Comparator<StudentList> {
public int compare(StudentList s1, StudentList s2) {
return s1.name.compareTo(s2.name);
}
}
class CourseComparator implements Comparator<StudentList> {
public int compare(StudentList s1, StudentList s2) {
return s1.course.compareTo(s2.course);
}
}
最佳答案
您只需将两个比较放在一个比较器中即可。
- 首先测试
name
是否相等:- 如果不相等,则返回
name
的比较结果。 - 如果相等,则继续比较
类(class)
:
- 如果不相等,则返回
以下比较器可以工作:
class NameCourseComparator implements Comparator<StudentList> {
public int compare(StudentList s1, StudentList s2) {
if (s1.name.equals(s2.name)) {
return s1.course.compareTo(s2.course);
}
return s1.name.compareTo(s2.name);
}
}
关于java - java中如何对具有不同属性的列表进行排序,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/19354529/