Java中按组分类的单独方法

Question

1. 我有一个拥有许多受保护数据成员和处理这些数据成员的许多不同函数组的类。
2. 我想分开这些类的子类，以便不同的方法组将在不同的子类。

1.I有这个类

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 
} 

我想要做这样的事情

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 

这将是更好，如果这些类不使用getter和setter方法

---

Upd

例如，我有这个类

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

而且我要手柄（）（或类似的东西），改造后的工作

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

Answer 1

从每个子类中延伸Student类。

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 
}