Java中按組分類的單獨方法

Question

1. 我有一個擁有許多受保護數據成員和處理這些數據成員的許多不同函數組的類。
2. 我想分開這些類的子類，以便不同的方法組將在不同的子類。

1.I有這個類

class Student { 
    protected String name; 
    protected int courseNumber; 
    protected TreeMap<String, Integer> marks; 
    protected double successRate; 
    protected Pair<String, Integer>[] conferences; //name, place 


    void setName(String name) { this.name = name; } 
    //... setters 
    String getName() { return name; } 
    //... getters 

    //...constructors 

    int getHashCode() { 
     int res = 0; 
     //... 
     return res; 
    } 
    boolean less (Student b) { 
     boolean ls = false; 
     //... 
     return ls; 
    } 
    //... functions to compare objects 

    String lastConferenceName() { 
     return conferences[conferences.length - 1].getKey(); 
    } 
    //... some last data 

    double marksMedium(String[] s) { 
     int res = 0; 
     for (int i = 0; i < s.length; i++) 
      res += marks.get(s[i]); 
     return (double) res/s.length; 
    } 
    //... some medium functions 

    //... some group of functions 

    //... some other groups 
} 

我想要做這樣的事情

class Student{ 
    protected String name; 
    protected int courseNumber; 
    protected TreeMap<String, Integer> marks; 
    protected double successRate; 
    protected Pair<String, Integer>[] conferences; //name, place 


    void setName(String name) { this.name = name; } 
    //... setters 
    String getName() { return name; } 
    //... getters 

    //...constructors 
} 

class StudentComparator{ 
    int getHashCode() { 
     int res = 0; 
     //... 
     return res; 
    } 
    boolean less (Student b) { 
     boolean ls = false; 
     //... 
     return ls; 
    } 
    //... functions to compare objects 
} 
class LastStudentInfoGetter{ 
    String lastConferenceName() { 
     return conferences[conferences.length - 1].getKey(); 
    } 
    //... some last data 
} 
class StudentMediumGetter{ 
    double marksMedium(String[] s) { 
     int res = 0; 
     for (int i = 0; i < s.length; i++) 
      res += marks.get(s[i]); 
     return (double) res/s.length; 
    } 
    //... some medium functions 
} 
class SomeStudentFunctions{ 
    //... some group of functions 
} 
///... SomeOtherClasses 

這將是更好，如果這些類不使用getter和setter方法

---

Upd

例如，我有這個類

class Handler{ 
    void handle(){ 
     Student s = new Student(); 
     ///////........ 
     System.out.println(s.lastConferenceName()); 
     System.out.println(s.getHashCode()); 
    } 
} 

而且我要手柄（）（或類似的東西），改造後的工作

注意lastConferenceName（）和GetHashCode（）是在不同的組

Answer 1

從每個子類中延伸Student類。

public class Student { 
    private String name; 
    private int courseNumber; 
    protected TreeMap<String, Integer> marks; 
    private double successRate; 
// protected Pair<String, Integer>[] conferences; // name, place 

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

    // ... setters 
    public String getName() { 
     return name; 
    } 
    // ... getters 

    // ...constructors 
} 

class StudentComparator extends Student{ 
    public int getHashCode() { 
     int res = 0; 
     // ... 
     return res; 
    } 

    public boolean less(Student b) { 
     boolean ls = false; 
     // ... 
     return ls; 
    } 
    // ... functions to compare objects 
} 


class StudentMediumGetter extends Student { 
    double marksMedium(String[] s) { 
     int res = 0; 
     for (int i = 0; i < s.length; i++) 
      res += marks.get(s[i]); 
     return (double) res/s.length; 
    } 
    // ... some medium functions 
} 

class SomeStudentFunctions extends Student { 
    // ... some group of functions 
}