结构模式－合成模式

合成模式：有时候也成为 部分－整体模式。合成模式将对象组织到树结构中，可以用来描述整体和部分的关系。合成模式可以是客户端将单纯元素与复合元素同等看待。

合成模式分为安全式合成模式和透明式合成模式

下面看安全式的合成模式：管理聚集的方法只出现在树枝构建类中，而不出现在树叶构建类中。

抽象构建：

package com.javapatterns.composite;

public interface Component {
    Composite getComposite();

    void sampleOperation();
}

 

树叶构建：

package com.javapatterns.composite;

public class Leaf implements Component {
    public Composite getComposite(){
        // Write your code here
        return null;
    }

    public void sampleOperation(){
        // Write your code here
    }
}

 

树枝构建：

package com.javapatterns.composite;

import java.util.Vector;
import java.util.Enumeration;

public class Composite implements Component
{
    public Composite getComposite()
    {
        return this;
    }

    public void sampleOperation()
    {
        java.util.Enumeration enumeration = components();
        while (enumeration.hasMoreElements())
        {
            ((Component)enumeration.nextElement()).sampleOperation();
        }
    }

    public void add(Component component)
    {
        componentVector.addElement(component);
    }

    public void remove(Component component)
    {
        componentVector.removeElement(component);
    }

    public Enumeration components()
    {
        return componentVector.elements();
    }

    private Vector componentVector = new java.util.Vector();
}

 

 透明式的合成模式：

抽象构建：

package com.javapatterns.composite.transparent;

import java.util.Enumeration;
public interface Component
{
    void sampleOperation();

    Composite getComposite();

    void add(Component component);

    void remove(Component component);

    Enumeration components();
}

 

树叶构建：

package com.javapatterns.composite.transparent;

import java.util.Enumeration;
import java.util.Vector;

public class Leaf implements Component
{
    public void sampleOperation()
    {
        // Write your code here
    }

    public void add(Component component)
    {
        componentVector.addElement(component);
    }

    public void remove(Component component)
    {
        componentVector.removeElement(component);
    }

    public Composite getComposite()
    {
        // Write your code here
        return null;
    }

    public Enumeration components()
    {
        // Write your code here
        return null;
    }

    /**
     * @associates <{Component}>
     * @link aggregation 
     * @supplierCardinality 0..*
     */
    private Vector componentVector = new java.util.Vector();
}

 

树枝构建：

package com.javapatterns.composite.transparent;

import java.util.Vector;
import java.util.Enumeration;

public class Composite implements Component
{
    public Composite getComposite()
    {
        return this;
    }

    public void sampleOperation()
    {
        java.util.Enumeration enumeration = components();
        while (enumeration.hasMoreElements())
        {
            ((Component)enumeration.nextElement()).sampleOperation();
        }
    }

    public void add(Component component)
    {
        componentVector.addElement(component);
    }

    public void remove(Component component)
    {
        componentVector.removeElement(component);
    }

    public Enumeration components()
    {
        return componentVector.elements();
    }

   
    private Vector componentVector = new java.util.Vector();
}