构造者模式

我会带着你远行 2021-11-23 07:44 260阅读 0赞

# 建造模式的本质: #

\-分离了对象子组件的单独构造（由Builder来负责）和装配（由Director负责）。从而可以构 造出复杂的对象。这个模式适用于：某个对象的构建过程复杂的情况下使用。

\-由于实现了构建和装配的解耦。不同的构建器,相同的装配，也可以做出不同的对象； 相同的构建器，不同的装配顺序也可以做出不同的对象。也就是实现了构建算法、装配 算法的解耦,实现了更好的复用。

/**
     * 宇宙飞船
     */
    public class AirShip {
        private OrbitalModule orbitalModule; //轨道舱
        private EngineModule engineModule;//发动机
        private EscapeTower escapeTower;//逃逸塔
    
        public AirShip(){
    
        }
        public void lauch(){
            System.out.println("-------------点火发射了！！！！---------------");
        }
    
        public AirShip(OrbitalModule orbitalModule, EngineModule engineModule, EscapeTower escapeTower) {
            this.orbitalModule = orbitalModule;
            this.engineModule = engineModule;
            this.escapeTower = escapeTower;
        }
    
        public OrbitalModule getOrbitalModule() {
            return orbitalModule;
        }
    
        public void setOrbitalModule(OrbitalModule orbitalModule) {
            this.orbitalModule = orbitalModule;
        }
    
        public EngineModule getEngineModule() {
            return engineModule;
        }
    
        public void setEngineModule(EngineModule engineModule) {
            this.engineModule = engineModule;
        }
    
        public EscapeTower getEscapeTower() {
            return escapeTower;
        }
    
        public void setEscapeTower(EscapeTower escapeTower) {
            this.escapeTower = escapeTower;
        }
    }
    
    class OrbitalModule {
        private String name;
    
        public OrbitalModule(String name) {
            this.name = name;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    }
    
    class EngineModule {
        private String name;
    
        public EngineModule(String name) {
            this.name = name;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
    }
    
    class EscapeTower {
        private String name;
    
        public EscapeTower(String name) {
            this.name = name;
        }
    
        public String getName() {
            return name;
        }
    
        public void setName(String name) {
            this.name = name;
        }
    
    }
    
    //-------------------------------
    public interface AirShipBuilder {
        OrbitalModule builderOrbitalModule();
        EngineModule builderEngineModule();
        EscapeTower builderEscapeTower();
    
    
    }
    //-------------------------------
    public class BubbleTgAirShipBuilder implements AirShipBuilder{
        @Override
        public OrbitalModule builderOrbitalModule() {
    
            System.out.println("----BubbleTgAirShipBuilder--------构建BubbleTg轨道舱--------------");
            return new OrbitalModule("这是构建好多了的BubbleTg轨道舱");
        }
    
        @Override
        public EngineModule builderEngineModule() {
            System.out.println("----BubbleTgAirShipBuilder--------构建BubbleTg发动机--------------");
            return new EngineModule("这是构建好多了的BubbleTg发动机");
        }
    
        @Override
        public EscapeTower builderEscapeTower() {
            System.out.println("----BubbleTgAirShipBuilder--------构建BubbleTg逃逸塔--------------");
            return new EscapeTower("这是构建好多了的BubbleTg逃逸塔");
        }
    }
    //-------------------------------
    /**
     * 负责组装
     */
    public interface AirShipDirector {
    
        /**
         * 组装飞船对象
         * @return
         */
        AirShip directAirShip();
    }
    //-------------------------------
    /**
     *装配者，组装
     */
    public class BubbleTgAirshipDirector implements AirShipDirector {
        private AirShipBuilder builder;
    
        public BubbleTgAirshipDirector(AirShipBuilder builder) {
            this.builder = builder;
        }
    
        @Override
        public AirShip directAirShip() {
    
            EngineModule e  = builder.builderEngineModule();
            OrbitalModule o  = builder.builderOrbitalModule();
            EscapeTower et  = builder.builderEscapeTower();
            System.out.println("--------BubbleTgAirshipDirector---开始装配组装-----------");
            //装配成飞船对象
            AirShip ship= new AirShip();
            ship.setEngineModule(e);
            ship.setEscapeTower(et);
            ship.setOrbitalModule(o);
            return ship;
        }
    }
    //-------------------------------
    public class builderPatternTest01 {
        public static void builderPatternTest(){
    
            System.out.println("----------------------------构建者模式演示开始------------------------------------");
            AirShipDirector director = new BubbleTgAirshipDirector(new BubbleTgAirShipBuilder());
            AirShip ship = director.directAirShip();
    
            System.out.println(ship.getEngineModule().getName());
            System.out.println(ship.getEscapeTower().getName());
            System.out.println(ship.getOrbitalModule().getName());
            System.out.println("-------------------一切就绪------------------");
            ship.lauch();
    
            System.out.println("----------------------------构建者模式演示结束------------------------------------");
    
        }
    }

# 开发中应用场景： #

\-StringBuilder类的append方法

\-SQL中的PreparedStatement

\-JDOM中，DomBuilder、SAXBuilder