按車牌號比較汽車物件列表

Question

好吧，我正在做一個相當複雜的任務。基本上我有一類汽車，然後是它的子類（乘用車和非乘客），然後是它們的子類（超小型汽車，小型皮卡車等）。我也有一個sort.java類和各種排序方法。我應該創造一系列汽車，並且他們按照車牌號對它們進行分類。

Automobile class: 

public class Automobile{ 
public String Name; 
public String Colour; 
public String plateNum; 

public Automobile (String eName, String eColour, String eplateNum) 
{ 
    Name = eName; 
    Colour = eColour; 
    plateNum = eplateNum; 
} 
public String toString() 
{ 
String result = "Name: " + Name +"\n"; 
result += "Colour: "+Colour+"\n"; 
result+= "Plate Number: "+ plateNum; 

return result; 
} 


}//end Automobile 

轎車類：

abstract public class passengerCar extends Automobile{ 
public abstract double fee(); 
public passengerCar (String eName, String eColour, String eplateNum) 
{ 
    super (eName, eColour, eplateNum); 

} 

public String toString() 
{ 
    String result = super.toString(); 

    result += "\n Fee: "+fee(); 

    return result; 
} 


} 

微型類：（子類的實例）

public class subCompact extends passengerCar{ 
public double litres; 
public subCompact (String eName, String eColour, String eplateNum, double eLitres) 
{ 
    super (eName, eColour, eplateNum); 
    litres = eLitres; 

} 
public double fee(){ 
double cost = (litres/10); 
return cost; 
} 

}

Database類：

public class CarDataBase{ 

private Automobile[] database; 
private int count; 

//creates initially empty database 
public CarDataBase() 
{ 
database = new Automobile[100]; 
count =0; 
} 


public void addminiCompact(String eName, String eColour, String eplateNum, double eLitres) 
{ 
    if(count == database.length) 
    increasesize(); 
    database[count] = new miniCompact (eName, eColour, eplateNum, eLitres); 
    count++; 
} 
public void addsubCompact(String eName, String eColour, String eplateNum, double eLitres) 
{ 
    if(count == database.length) 
    increasesize(); 
    database[count] = new subCompact (eName, eColour, eplateNum, eLitres); 
    count++; 
} 
public void addCompact(String eName, String eColour, String eplateNum, double eLitres) 
{ 
    if(count == database.length) 
    increasesize(); 
    database[count] = new Compact (eName, eColour, eplateNum, eLitres); 
    count++; 
} 
public void addMidsize(String eName, String eColour, String eplateNum, double eLitres) 
{ 
    if(count == database.length) 
    increasesize(); 
    database[count] = new Midsize (eName, eColour, eplateNum, eLitres); 
    count++; 
} 
public void addLarge(String eName, String eColour, String eplateNum, double eLitres) 
{ 
    if(count == database.length) 
    increasesize(); 
    database[count] = new Large (eName, eColour, eplateNum, eLitres); 
    count++; 
} 
public void addSmallPickup(String eName, String eColour, String eplateNum, double eGvwr) 
{ 
    if(count == database.length) 
    increasesize(); 
    database[count] = new SmallPickup (eName, eColour, eplateNum, eGvwr); 
    count++; 
} 
public void addStandardPickup(String eName, String eColour, String eplateNum, double eGvwr) 
{ 
    if(count == database.length) 
    increasesize(); 
    database[count] = new StandardPickup (eName, eColour, eplateNum, eGvwr); 
    count++; 
} 
public void addVan(String eName, String eColour, String eplateNum) 
{ 
    if(count == database.length) 
    increasesize(); 
    database[count] = new Van (eName, eColour, eplateNum); 
    count++; 
} 
public void addTwoSeater(String eName, String eColour, String eplateNum) 
{ 
    if(count == database.length) 
    increasesize(); 
    database[count] = new TwoSeater (eName, eColour, eplateNum); 
    count++; 
} 
public void addSpecialPurpose(String eName, String eColour, String eplateNum, double eGvwr) 
{ 
    if(count == database.length) 
    increasesize(); 
    database[count] = new SpecialPurpose (eName, eColour, eplateNum, eGvwr); 
    count++; 
} 
public String toString() 
{ 
String report = "~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n"; 
report +="Number of Vechicles: "+count+"\n\n"; 
report+= "Vehicle list:\n\n"; 
for (int i = 0; i< count; i++) 
    { 
    report+= database[i]+"\n\n"; 
    } 
return report; 
} 



private void increasesize() 
{ 
Automobile[] temp = new Automobile[database.length *2]; 
for (int car = 0; car<database.length; car++) 
    temp[car] = database[car]; 
    database = temp; 
} 
} 

驅動程序類：類Sorting.java

public class Driver implements Comparable{ 
public static void main(String[] args){ 

CarDataBase db = new CarDataBase(); 

db.addsubCompact("Ford","blue","ABC123",2500); 
db.addSmallPickup("Chevrolet","green","CBA321", 4000); 
Sorting.insertionSort(db); 
System.out.print(db.toString()); 


} 
} 

插入排序方法

//----------------------------------------------------------------- 

// Sorts the specified array of objects using the insertion 

// sort algorithm. 

//----------------------------------------------------------------- 

public static void insertionSort (Comparable[] list) 

{ 

    for (int index = 1; index < list.length; index++) 

    { 

    Comparable key = list[index]; 

    int position = index; 

// Shift larger values to the right 

    while (position > 0 && key.compareTo(list[position-1]) > 0) 

    { 

     list[position] = list[position-1]; 

     position--; 

    } 

    list[position] = key; 

    } 

} 

} 

Answer 1

你一定要實現汽車Comparable<Automobile>並添加compareTo(Automobile)方法：

public int compareTo(Automobile o) { 
     if (o == null) 
      return -1; 
     if (this.plateNum == null) 
      return 1; 
     return this.plateNum.compareTo(o.plateNum); 
    }