Builder模式（生成）
我们创建复杂的对象时，会使用到此Builder模式，定义：它可以将复杂对象的初始化过程 抽象出来，使这个抽象过程的不同实现方法可以构建不同的表现（属性）对象。通过一步步构建，最终完成对象的构建。后面可以与抽象工厂做对比。
其实，还是有点绕，那就先认定一点builder模式==创建复杂对象，再往下看。
灵魂作图
示例代码：
代码语言：javascript复制public class BuilderTest {
public static void main(String[] args) {
Builder builder = new ConcreteBuilder2();
Director director = new Director(builder);
director.construct("一个对象:");
System.out.println(director.getProduct().toString());
//第二个对象
Builder builder1 = new ConcreteBuilder1();
Director director1 = new Director(builder1);
director1.construct("不同对象:");
System.out.println(director1.getProduct().toString());
}
}
class ComPlexProduct {
private String complexStr ;
private int plan ;
public void setComplexStr(String complexStr) {
this.complexStr = complexStr;
}
public void setPlan(int plan) {
this.plan = plan;
}
@Override
public String toString() {
return complexStr plan;
}
}
abstract class Builder { //构建product提取为抽象方法
protected ComPlexProduct product;
public void createProduct() {
product = new ComPlexProduct();
}
public ComPlexProduct getProduct() {
return product;
}
public abstract void setProductStr(String complexStr);
public abstract void setProductPlan();
}
class ConcreteBuilder1 extends Builder{ //构建一个复杂product
@Override
public void setProductStr(String complexStr) {
product.setComplexStr(complexStr "这有一个构建算法");
}
@Override
public void setProductPlan() {
product.setPlan(10);
}
}
class ConcreteBuilder2 extends Builder{
@Override
public void setProductStr(String complexStr) {
product.setComplexStr(complexStr "这有一个构建算法,还是非本地的");
}
@Override
public void setProductPlan() {
product.setPlan((int) (System.currentTimeMillis()));
}
}
class Director{
private Builder builder;
public Director(Builder builder) {
this.builder = builder;
}
public ComPlexProduct getProduct() {
return builder.getProduct();
}
public void construct(String productName) {
builder.createProduct();
builder.setProductPlan();
builder.setProductStr(productName);
}
}UML类图
