Builder mode is a creation mode, which creates a product that hides the creation process from the outside. Using a combination method, the director determines the construction process
Class diagram
##
public interface Builder {
void buildPartA();
void buildPartB();
void buildPartC();
}
public class BuilderImpl implements Builder {
@Override
public void buildPartA() {
System.out.println("建造部件A");
}
@Override
public void buildPartB() {
System.out.println("建造部件B");
}
@Override
public void buildPartC() {
System.out.println("建造部件C");
}
}
public class BuilderImpl2 implements Builder {
@Override
public void buildPartA() {
System.out.println("建造部件AA");
}
@Override
public void buildPartB() {
System.out.println("建造部件BB");
}
@Override
public void buildPartC() {
System.out.println("建造部件CC");
}
}
/**
* 指挥者：指导 如何 建造
* 组合Builder
* @author stone
*
*/
public class Director {
private Builder builder;
public Director(Builder builder) {
this.builder = builder;
}
/**
* 建造方法：定义了建造的流程
* 如果需要其他流程来实现，再new一个指挥者Director就可
*/
public void construct() {
System.out.println("director 指挥 builder进行建造");
builder.buildPartA();
builder.buildPartB();
builder.buildPartC();
}
}
/**
* 指挥者：指导 如何 建造
* 组合Builder
* @author stone
*
*/
public class Director2 {
private Builder builder;
public Director2(Builder builder) {
this.builder = builder;
}
/**
* 建造方法：定义了建造的流程
* 如果需要其他流程来实现，再new一个指挥者Director就可
*/
public void construct() {
System.out.println("director2 指挥 builder进行建造");
builder.buildPartB();
builder.buildPartC();
builder.buildPartA();
}
}
/*
* 建造者模式：建造者模式则是将各种产品集中起来进行管理，用来创建复合对象，
*
* 将一个复杂对象的构造与它的表示分离，使同样的构建过程可以创建不同的表示，这样的设计模式被称为建造者模式
*/
public class Test {
public static void main(String[] args) {
Builder builder = new BuilderImpl();
Director director = new Director(builder);
/*
* 同样的构建过程，不同的模块(buildPartA、buildPartB、buildPartC)实现， new一个builder的实现
* 不同的构建过程，new 一个director
* 不同的构建过程，不同的模块实现， new director，new builder
*/
director.construct();
System.out.println("");
Builder builder2 = new BuilderImpl2();
Director director2 = new Director(builder2);
director2.construct();
System.out.println("");
Builder builder3 = new BuilderImpl2();
Director2 director3 = new Director2(builder3);
director3.construct();
}
}Print: director 指挥 builder进行建造 建造部件A 建造部件B 建造部件C director 指挥 builder进行建造 建造部件AA 建造部件BB 建造部件CC director2 指挥 builder进行建造 建造部件BB 建造部件CC 建造部件AA
In real development, the role of Director may often be omitted , directly use Builder to build products;
The characteristic of this product is that there are many attributes, most of which have default values. Through some basic default attributes, a basic product can be built ;
Builder mostly uses chain calls, such as Product p = new Builder().setA().setB().build();
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