我查看了使用抽象工厂和工厂方法的示例。但是我怎样才能正确地将两者结合起来,所以抽象工厂会选择需要哪个混凝土工厂,然后工厂方法会选择在给定工厂中创建什么。我试图使用这些模式使自己成为一个程序,但陷入了死胡同。无法弄清楚如何正确组合这两种模式以使我的程序正常工作。我的程序非常简单。它只会创造家具 - 桌子或椅子,取决于工厂选择的混凝土。
然后,如果选择表格工厂,它将创建圆桌或方桌(也写入类型,圆形或方形(。那么椅子工厂也是如此,如果选择该工厂。
所以我的代码看起来像这样(有些部分可能不正确,因为这就是我问这个问题的原因(:
package pack1;
//abstract product
public abstract class Table {
protected final String name;
public Table(String name) {
this.name = name;
}
}
package pack1;
//concrete product
public class SquareTable extends Table {
public SquareTable(String name) {
super(name);
}
}
package pack1;
//concrete product
public class RoundTable extends Table {
public RoundTable(String name) {
super(name);
}
}
package pack1;
//abstract product
public abstract class Chair {
protected final String name;
public Chair(String name) {
this.name = name;
}
}
package pack1;
//concrete product
public class WoodenChair extends Chair {
public WoodenChair(String name) {
super(name);
}
}
package pack1;
//concrete product
public class MetalChair extends Chair {
public MetalChair(String name) {
super(name);
}
}
package pack1;
//Abstract Factory
public interface AbstractFurnitureFactory {
public Table createTable(String type, String name);
//not finished. How to use different create methods for different factories,
//so it wouldn't require to use this method in concrete factories or
//do I need 2 concrete factories for this to work?..
}
package pack1;
//concrete factory
public class TableFactory implements AbstractFurnitureFactory {
public Table createTable(String type, String name){
if(type.equals("square"))
{
SquareTable sq_table=new SquareTable(name);
return sq_table;
}
else
{
RoundTable rn_table=new RoundTable(name);
return rn_table;
}
}
}
package pack1;
//concrete factory
public class ChairFactory {
public Chair createChair(String type, String name){
if(type.equals("wood"))
{
WoodenChair wd_chair=new WoodenChair(name);
return wd_chair;
}
else
{
MetalChair mt_chair=new MetalChair(name);
return mt_chair;
}
}
}
package pack1;
//client
public class FurnitureBuilder {
public void buildTable(AbstractFurnitureFactory tf)
{
//Table table = tf.createTable();
//table.name = "New table";
//not Finished. Java won't let me set arguments in createTable
//method for example. It gives error - 'The method
//createTable(String, String) in the type
//AbstractFurnitureFactory is not applicable for the arguments ()'
}
}
package pack1;
public class Main {
public static void main(String[] args)
{
//FurnitureBuilder builder = new FurnitureBuilder();
//AbstractFurnitureFactory TableFactory = null;
//Not finished as some parts are missing.
}
}
因此,如果有人能查明和/或纠正我做错了什么,我将不胜感激。
我认为您混淆了哪些工厂应该从哪个抽象工厂继承。
更好的Factory
设计是让同一家工厂生产不同种类的Tables
或Chairs
。 这使得不需要AbstractFurnitureFactory
。
例如:
public interface TableFactory{
Table createTable(String name);
}
public class SquareTableFactory implements TableFactory{
@Override
Table createTable(String name){
return new SquareTable(name);
}
}
public class RoundTableFactory implements TableFactory{
@Override
Table createTable(String name){
return new RoundTable(name);
}
}
然后
public class FurnitureBuilder {
private final TableFactory tf;
private final ChairFactory cf;
...
public void buildTable(String name){
Table table = tf.createTable(name);
...
}
}
希望这能让事情更清楚。