java 设计模式之生成器模式

生成器模式：将一个复杂对象的构建与它的表示分离，使同样的构建过程可以创建不同的表示（Separate the construction of a complex object from its representation so that the same construction process can create different representations）。

生成器模式结构中的四种角色。

产品(Product）： 所要构建的复杂对象。

抽象生成器(Builder): 抽象生成器是一个接口，该接口除了为创建一个Product对象的各个组件定义若干个方法外，还要定义返回Product对象的方法。

具体生成器(ConcreteBuilder): 实现Buidler接口的类。

指挥者(Director): 指挥者是一个类，该类需含有Builder接口申明的变量，指挥者的职责是负责向用户提供具体的生成器，利用具体生成器构造复杂的Product对象。

代码如下：

Product类：

package cn.zj.qiao.designPattern.builder;

import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class PanelProduct extends JPanel {
    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    JButton button;
    JLabel label;
    JTextField textField;
}

Builder 接口：

package cn.zj.qiao.designPattern.builder;

import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class PanelProduct extends JPanel {
    /**
     * 
     */
    private static final long serialVersionUID = 1L;
    JButton button;
    JLabel label;
    JTextField textField;
}

ConcreteBuilder 如下两个类（ConcreteBuilderOne和ConcreteBuilderTwo)：

package cn.zj.qiao.designPattern.builder;


import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class ConcreteBuilderOne implements Builder {
    private PanelProduct panel;    //创建需要的容器
    
    ConcreteBuilderOne(){
        panel = new PanelProduct();
    }
    @Override
    public void buildButton() {
        panel.button = new JButton("btn");

    }

    @Override
    public void buildLabel() {
        panel.label = new JLabel("lable");

    }

    @Override
    public void buildTextField() {
        panel.textField = new JTextField("hello");

    }

    @Override
    public JPanel getPanel() {
        panel.add(panel.button);
        panel.add(panel.label);
        panel.add(panel.textField);
        return panel;
    }

}


package cn.zj.qiao.designPattern.builder;

import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

public class ConcreteBuilderTwo implements Builder {
    private PanelProduct panel;
    
    ConcreteBuilderTwo(){
        panel = new PanelProduct();
    }
    @Override
    public void buildButton() {
        panel.button = new JButton("btn");

    }

    @Override
    public void buildLabel() {
        panel.label = new JLabel("label");

    }

    @Override
    public void buildTextField() {
        panel.textField = new JTextField("helo");

    }

    @Override
    public JPanel getPanel() {
        panel.add(panel.textField);
        panel.add(panel.label);
        panel.add(panel.button);
        return panel;
    }

}

Director类：

package cn.zj.qiao.designPattern.builder;

import javax.swing.JPanel;

public class Director {
    private Builder builder;
    
    Director(Builder builder){
        this.builder = builder;
    }
    
    public JPanel constructProduct(){
        builder.buildButton();
        builder.buildLabel();
        builder.buildTextField();
        return     builder.getPanel();
    }
}

下面是测试代码：

package cn.zj.qiao.designPattern.builder;

import java.awt.Container;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class Application {
    public static void main(String[] args){
            Builder builder = new ConcreteBuilderOne();
            Director dir = new Director(builder);
            JPanel panel = dir.constructProduct();
            JFrame frameOne = new JFrame("hello");
            Container con = frameOne.getContentPane();
            con.add(panel);
            frameOne.setBounds(12, 12, 200, 120);
            frameOne.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frameOne.setVisible(true);
            
            builder = new ConcreteBuilderTwo();
            dir = new Director(builder);
            panel = dir.constructProduct();
            JFrame frameTwo = new JFrame("hello");
            con = frameTwo.getContentPane();
            con.add(panel);
            frameTwo.setBounds(222, 12, 200, 120);
            frameTwo.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frameTwo.setVisible(true);
            
        }
}