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package class06;
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import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.Comparator;
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public class ShowComparator {
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public static class Student {
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public String name;
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public int id;
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public int age;
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public Student(String name, int id, int age) {
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this.name = name;
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this.id = id;
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this.age = age;
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}
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}
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// 谁id大，谁放前！
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public static class IdComparator implements Comparator<Student> {
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// 如果返回负数，认为第一个参数应该排在前面
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// 如果返回正数，认为第二个参数应该排在前面
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// 如果返回0，认为谁放前面无所谓
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@Override
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public int compare(Student o1, Student o2) {
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if (o1.id < o2.id) {
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return 1;
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} else if (o2.id < o1.id) {
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return -1;
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} else {
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return 0;
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}
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}
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}
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// 谁age大，谁放前！
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public static class AgeComparator implements Comparator<Student> {
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// 如果返回负数，认为第一个参数应该排在前面
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// 如果返回正数，认为第二个参数应该排在前面
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// 如果返回0，认为谁放前面无所谓
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@Override
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public int compare(Student o1, Student o2) {
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if (o1.age < o2.age) {
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return 1;
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} else if (o2.age < o1.age) {
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return -1;
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} else {
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return 0;
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}
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}
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}
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public static void printArray(int[] arr) {
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for (int i = 0; i < arr.length; i++) {
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System.out.print(arr[i] + " ");
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}
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System.out.println();
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}
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public static void printStudents(Student[] students) {
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for (int i = 0; i < students.length; i++) {
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System.out.println(students[i].name + ", " + students[i].id + ", " + students[i].age);
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}
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}
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public static void main(String[] args) {
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int[] arr = { 8, 1, 4, 1, 6, 8, 4, 1, 5, 8, 2, 3, 0 };
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printArray(arr);
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Arrays.sort(arr);
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printArray(arr);
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Student s1 = new Student("张三", 5, 27);
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Student s2 = new Student("李四", 1, 17);
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Student s3 = new Student("王五", 4, 29);
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Student s4 = new Student("赵六", 3, 9);
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Student s5 = new Student("左七", 2, 34);
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Student[] students = { s1, s2, s3, s4, s5 };
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printStudents(students);
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System.out.println("=======");
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Arrays.sort(students, new IdComparator());
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printStudents(students);
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System.out.println("=======");
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ArrayList<Student> arrList = new ArrayList<>();
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arrList.add(s1);
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arrList.add(s2);
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arrList.add(s3);
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arrList.add(s4);
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arrList.add(s5);
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for (Student s : arrList) {
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System.out.println(s.name + ", " + s.id + ", " + s.age);
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}
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System.out.println("=======");
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arrList.sort(new AgeComparator());
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for (Student s : arrList) {
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System.out.println(s.name + ", " + s.id + ", " + s.age);
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}
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}
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}
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