Question

很抱歉，这可能是一个简单的解决方案，但我在创建一个对象时遇到麻烦，该对象将使用Java中另一个类构造函数参数的参数。本质上，我有这个具有某些参数的Inv对象，我试图仅使用Inv对象中的某些参数创建一个Warehouse对象，然后将在Warehouse Transaction类中使用。我可以在Inv对象构造函数中执行if语句吗？ Anywho，我稍后会把这个对象推到一个堆栈上，但我无法开发创建第二个对象的逻辑。请帮助，我对此非常陌生。

public class InvTrans

{

private int InvTransIndex = 0;
private Inv[] transactionArray;

public InvTrans()
{
    this.transactionArray = new Inv[100];
}

public static void main(String args[])
{
    InvTrans widget = new InvTrans();



    Inv order1 = new Inv("March 5th, 2016", "Received", 20, 0001, 2.10, 2.20);
    Inv order2 = new Inv("March 6th, 2016", "Received", 100, 0002, 2.10, 2.50);
    Inv order3 = new Inv("March 7th, 2016", "Received", 100, 0003, 2.10, 2.50);
    Inv order4 = new Inv("March 12th, 2016", "Sold", 140, 0004, 2.40, 2.60);


    widget.addLine(order1);
    widget.addLine(order2);
    widget.addLine(order3);
    widget.addLine(order4);



    for (int counter = 0; counter < widget.transactionArray.length; counter++)
    {
        widget.transactionArray[counter].display();
    }

}

public void addLine(Inv a)
{

    transactionArray[InvTransIndex] = a;
    InvTransIndex = InvTransIndex + 1;
}
}

class Inv
{
String date, type;
int units, referenceNumber;
double costPerUnit, pricePerUnit;

Inv(String d, String t, int u, int r, double c, double p) {
    this.date = d;
    this.type = t;
    this.units = u;
    this.referenceNumber = r;
    this.costPerUnit = c;
    this.pricePerUnit = p;


    Warehouse warehouseTransaction = new Warehouse(this.date, this.type, this.units, this.costPerUnit);

}

public void display()
{
     System.out.println(this.date + "\t" + this.type + "\t" + this.units + "\t\t\t\t\t" + this.referenceNumber + "\t\t\t\t\t" + this.costPerUnit + "\t\t\t" + this.pricePerUnit);
}
}    

public class Warehouse
{
    String date, type = "";
    int units = 0;
    double costPerUnit = 0;
    Warehouse(String d, String t, int u, double c)
    {
        date = d;
        type = t;
        units = u;
        costPerUnit = c;
    }
}

Answer 1

您可以使用工厂模式：

创建一个名为InvFactory的类。这个类可以访问Warehouse（顺便说一句，仓库是你存储所有项目的地方......创建一个新的对象仓库每次创建一个Inv对我来说都没有意义。这里我将这些对象称为WarehouseItem）。当您想要创建Inv时，您将调用工厂而不是Inv构造函数

public class InvFactory
{ 
    private LinkedList<WarehouseItem> _warehouse = new LinkedList<WarehouseItem;

    public CreateInv(String d, String t, int u, int r, double c, double p)
    {
        Inv inv = new Inv(d, t, u, r, c, p);
        _warehouse.add(new WarehouseItem(d, t, u, c);
        return inv;
    }

    public LinkedList<WarehouseItem> getWarehouse()
    {
        return _warehouse;
    }
}

在主要方法中，您可以替换

Inv order1 = new Inv("March 5th, 2016", "Received", 20, 0001, 2.10, 2.20);
Inv order2 = new Inv("March 6th, 2016", "Received", 100, 0002, 2.10, 2.50);
Inv order3 = new Inv("March 7th, 2016", "Received", 100, 0003, 2.10, 2.50);
Inv order4 = new Inv("March 12th, 2016", "Sold", 140, 0004, 2.40, 2.60);

通过

InvFactory factory = new InvFactory();

Inv order1 = factory.CreateInv("March 5th, 2016", "Received", 20, 0001, 2.10, 2.20);
Inv order2 = factory.CreateInv("March 6th, 2016", "Received", 100, 0002, 2.10, 2.50);
Inv order3 = factory.CreateInv("March 7th, 2016", "Received", 100, 0003, 2.10, 2.50);
Inv order4 = factory.CreateInv("March 12th, 2016", "Sold", 140, 0004, 2.40, 2.60);

此时，您可以通过调用来查看列表中的所有项目。

factory.getWarehouse();

我希望这会有所帮助

尝试使用一个类构造函数来使用另一个类构造函数中的一些参数

1 个答案: