【Java设计模式】构造器模式

【定义】

将构造过程与表示分开，以便于相同的构造过程创建不同的表示。

如果对象的构造过程相对复杂，这样的构造模式会非常有效。

【实例】

我们需要根据需求组装相应的计算机，例如硬盘500G，内存8G，CPU8核等等。

【实现】

定义构造步骤：

interface IBuilder
{
void BuildBody();
void InsertWheels();
void AddHeadlights();
Product GetVehicle();
}

定义一辆车的构造方法：

class Car implements IBuilder
{
private Product product = new Product();
@Override
public void BuildBody()
{
product.Add("This is a body of a Car");
}
@Override
public void InsertWheels()
{
product.Add("4 wheels are added");
}
@Override
public void AddHeadlights()
{
product.Add("2 Headlights are added");
}
@Override
public Product GetVehicle()
{
return product;
}
}

定义摩托车的构造方法：

// Motorcycle is a ConcreteBuilder
class MotorCycle implements IBuilder
{
private Product product = new Product();
@Override
public void BuildBody()
{
product.Add("This is a body of a Motorcycle");
}
@Override
public void InsertWheels()
{
product.Add("2 wheels are added");
}
@Override
public void AddHeadlights()
{
product.Add("1 Headlights are added");
}
@Override
public Product GetVehicle()
{
return product;
}
}

定义产品：

// "Product"
class Product
{
// We can use any data structure that you prefer. We have used LinkedList here.
private LinkedList parts;
public Product()
{
parts = new LinkedList();
}
public void Add(String part)
{
//Adding parts
parts.addLast(part);
}
public void Show()
{
System.out.println("\n Product completed as below :");
for(int i=0;i

生产商：


// "Director"
class Director
{
IBuilder myBuilder;
// A series of steps—for the production
public void Construct(IBuilder builder)
{
myBuilder=builder;
myBuilder.BuildBody();
myBuilder.InsertWheels();
myBuilder.AddHeadlights();
}
}

测试：