自定义容器排序规则

自定义容器排序规则

• 继承并重写Comparable<?>接口

• 向排序函数中传入比较器

  package LeetCode;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Comparator;
  import java.util.List;
  
  /**
   * @ClassName TestComperator
   * @Description 自定义排序规则
   * 1.继承并重写Comparable接口
   * 2.传入一个比较器
   * @Author m
   * @Version 1.0
   */
  
  class Person implements Comparable<Person>{
      int age;
  
      String name;
  
      @Override
      public String toString() {
          return "Person{" +
                  "age=" + age +
                  ", name='" + name + '\'' +
                  '}';
      }
  
      public Person() {
      }
  
      public Person(int age, String name) {
          this.age = age;
          this.name = name;
      }
  
      //重写比较器，按年龄从小到大，姓名从小到大
      @Override
      public int compareTo(Person o) {
          if(age != o.age){
              return age-o.age;
          }else {
              return name.compareTo(o.name);
          }
      }
  
  }
  
  
  public class TestComperator {
  
  
      public static void main(String[] args) {
          List<Person> list = new ArrayList<>();
          list.add(new Person(1,  "zli"));
          list.add(new Person(2,  "ayy"));
          list.add(new Person(2,  "bob"));
  
          Collections.sort(list, new Comparator<Person>() {
              //年龄从大到小，姓名从小到大
              @Override
              public int compare(Person o1, Person o2) {
                  if(o2.age != o1.age){
                      return o2.age-o1.age;
                  }else {
                      return o1.name.compareTo(o2.name);
                  }
              }
          });
  
          System.out.println("年龄从大到小，姓名从小到大");
          for (Person person : list) {
              System.out.println(person);
          }
  
          System.out.println("年龄从小到大，姓名从小到大");
          Collections.sort(list);
  
          for (Person person : list) {
              System.out.println(person);
          }
  
      }
  
  
  }
  
  

  注意事项：

  当你的自定义类即重写了Comparable接口，也传入了比较器时，以比较器为准

  运行结果