我有一個人員對象的數(shù)組列表，每個對象都有名字、姓氏和年齡。我想使用內(nèi)部類提供一種按名字對這些對象進行排序的方法。我如何訪問內(nèi)部類中重寫的compareTo方法？我想使用內(nèi)部類，因為一旦按名字排序起作用，我將創(chuàng)建內(nèi)部類以按其他屬性排序。package listdemo;import java.util.ArrayList;import java.util.Collections;import java.util.List;public class ListDemo { public static void main(String[] args) { List<Person> people = new ArrayList<>(); people.add(new Person("Homer", "Simpson", 29)); people.add(new Person("Mo", "Sizlak", 23)); people.add(new Person("Bart", "Simpson", 22)); people.add(new Person("Peter", "Griffin", 30)); people.add(new Person("Joe", "Swanson", 27)); }}package listdemo;public class Person { private String firstName; private String lastName; private int age; public Person(String firstName, String lastName, int age) { this.firstName = firstName; this.lastName = lastName; this.age = age; //create an instance of the inner class upon initialization of Person Person.CompareFirstName compareFirstName = this.new CompareFirstName(); } public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } @Override public String toString() { return this.firstName + " " + this.lastName + " " + this.age; } class CompareFirstName implements Comparable<Person> { @Override public int compareTo(Person comparePerson) { System.out.println("inner class compareTo method invoked"); int difference = Person.this.firstName.compareTo(comparePerson.getFirstName()); return difference; } }}
1 回答
小唯快跑啊
TA貢獻1863條經(jīng)驗 獲得超2個贊
類比較名字
class compareFirstName implements Comparator<Person>{
@override
public int compareTo(Person p1,Person p2){
return p1.getFirstName().compareTo(p2.getFirstName());
}
}
在您的主要方法上創(chuàng)建上述類的實例并使用 Collections 類進行排序
compareFirstName c = new compareFirstName ();
List<Person> yourPersonList = new ArrayList<>();
.........................
Collections.sort(yourPersonList, c);
for(Person p : yourPersonList) {
System.out.println(p.getFirstName()+","+p.getLastName()+","+p.getAge());
}
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