Interface comparator

public class Study04 {
// Define a method to sort all classes , The premise is that classes must be familiar comparable1 Interface
// Use polymorphism , Use interface classes to reference arrays as formal parameters , Receive different argument arrays
public static void sort(Comparable1[] comparable1s) {
for (int i = 1; i < comparable1s.length; i++) {// Control the number of trips
// Operations performed per trip , Start with the first element and compare two adjacent elements , If the sorting conditions are met , Exchange two element values
// Define a tag variable before the start of each trip
boolean flag = true;
for (int j = 0; j < comparable1s.length - i; j++) {
// Meet the conditions for exchange
if (comparable1s[j].compareTo(comparable1s[j + 1]) > 0) {
Comparable1 temp;
temp = comparable1s[j];
comparable1s[j] = comparable1s[j + 1];
comparable1s[j + 1] = temp;
flag = false;// If there's an exchange , Change the value of the tag variable

            }
        }
        if (flag) {
            break;

        }
    }
}

public static void main(String[] args) {
    /**
     *  Interface internal comparator 
     */
    Student001 st1 = new Student001(" Xiao Huang ", 2, 98);
    Student001 st2 = new Student001(" Little green ", 23, 98);
    Student001 st3 = new Student001(" Little ice ", 1, 90);
    Student001 st4 = new Student001(" petty thief ", 32, 8);
    Student001 st5 = new Student001(" Xiao Chen ", 5, 28);
    Student001[] stt = {st1, st2, st3, st4, st5};
    System.out.println(" Traverse the array before sorting =======");
    for (Student001 st : stt
    ) {
        System.out.println(st.toString());

    }
    sort(stt);
    // Traverse the sorted array 
    System.out.println(" Traverse the sorted array =======");
    for (Student001 st : stt
    ) {
        System.out.println(st.toString());
    }
}

}

interface Comparable1 {
//Object type , You can pass in several subtypes , Polymorphic usage ;
public int compareTo(Object object);
}

// Create subclasses to implement interfaces

class Student001 implements Comparable1 {

private String name;
private int id;
private double score;

// Define nonparametric construction methods 
public Student001() {

}

public Student001(String name, int id, double score) {
    super();
    this.name = name;
    this.id = id;
    this.score = score;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

public double getScore() {
    return score;
}

public void setScore(double score) {
    this.score = score;
}

@Override
public String toString() {
    return "Student001{" +
            "name='" + name + '\'' +
            ", id=" + id +
            ", score=" + score +
            '}';
}

@Override
public int compareTo(Object object) {
    Student001 student001 = (Student001) object;
    int result = this.id - student001.id;
    return result;
}

}

External comparator

public class Student05 {
public static void sort(Object[] objects, Comparator01 comparator01) {
for (int i = 1; i < objects.length; i++) {// Control the number of trips

        // Operations performed per trip , Start with the first element and compare two adjacent elements , If the sorting conditions are met , Exchange two element values 
        // Define a tag variable before the start of each trip 
        boolean flag = true;
        for (int j = 0; j < objects.length - i; j++) {
            // Meet the conditions for exchange 
            if (comparator01.compare(objects[j], objects[j + 1]) > 0) {
                Object temp;
                temp = objects[j];
                objects[j] = objects[j + 1];
                objects[j + 1] = temp;
                flag = false;// If there's an exchange , Change the value of the tag variable 

            }
        }
        if (flag) {
            break;

        }
    }
}

public static void main(String[] args) {
    /**
     *  Interface internal comparator 
     */
    Student002 st1 = new Student002(" Xiao Huang ", 2, 98);
    Student002 st2 = new Student002(" Little green ", 23, 98);
    Student002 st3 = new Student002(" Little ice ", 1, 90);
    Student002 st4 = new Student002(" petty thief ", 32, 8);
    Student002 st5 = new Student002(" Xiao Chen ", 5, 28);
    Student002[] stt = {st1, st2, st3, st4, st5};
    // Define an external comparator object 
    StuIdComp stuIdComp = new StuIdComp();
    System.out.println(" Traverse the array before sorting =======");
    for (Student002 st : stt
    ) {
        System.out.println(st.toString());

    }
    sort(stt, stuIdComp);
    // Traverse the sorted array 
    System.out.println(" Traverse the sorted array =======");
    for (Student002 st : stt
    ) {
        System.out.println(st.toString());
    }
}

}

// Define an external comparator
interface Comparator01 {
// Formal parameters are Object type , With polymorphism
public int compare(Object obj1, Object Obj2);
}

class StuIdComp implements Comparator01 {

@Override
public int compare(Object obj1, Object Obj2) {
    // Cast 
    Student002 st = (Student002) obj1;
    Student002 st01 = (Student002) Obj2;
    int result = st.getId() - st01.getId();
    return result;
}

}

// Define the student class
class Student002 {
private String name;
private int id;
private double score;

public Student002() {
}

public Student002(String name, int id, double score) {
    super();
    this.name = name;
    this.id = id;
    this.score = score;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
}

public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

public double getScore() {
    return score;
}

public void setScore(double score) {
    this.score = score;
}

@Override
public String toString() {
    return "Student002{" +
            "name='" + name + '\'' +
            ", id=" + id +
            ", score=" + score +
            '}';
}

}