Builder模式?(好熟悉,貌似有说不上来),在这里好好总结一下。
Builder模式的介绍
Builder模式是一步一步创建一个复杂对象的创建者模式, 它允许用户在不知道内部构建细节的情况下,可以精确的控制对象的构造流程。该模式为了将构建复杂对象的过程和它的部件解耦,将一个复杂对象的创建与它的表示分离,使得同样的构建过程可以创建不同的表示,
Builder模式的角色介绍
- Product产品类 (产品的抽象类)
- Builder (抽象Builder,规范产品的组件,一般有子类实现具体的组件过程)
- ConcreteBuilder(具体的Builder类)
- Director (统一组装过程)
代码
public abstract class Product {
/**
* 计算机抽象类(Product)
*/
protected String mBoard;
protected String mDisplay;
protected String mOs;
public void setmBoard(String mBoard) {
this.mBoard = mBoard;
}
public void setmDisplay(String mDisplay) {
this.mDisplay = mDisplay;
}
//设置操作系统,让子类自己去实现
public abstract void setmOs();
}
public class MacBook extends Product {
/**
* 具体的Computer类, MacBook
*/
@Override
public void setmOs() {
mOs = "苹果系统10.00";
}
}
public abstract class Builder {
/**
* 抽象Builder
*/
public abstract void buildBoard(String board);
public abstract void buildDisplay(String display);
public abstract void buildOs();
public abstract Product create();
}
public class MacbookBuilder extends Builder {
/**
* 具体的Builder
*/
private Product product = new MacBook();
@Override
public void buildBoard(String board) {
product.setmBoard(board);
}
@Override
public void buildDisplay(String display) {
product.setmDisplay(display);
}
@Override
public void buildOs() {
product.setmOs();
}
@Override
public Product create() {
return product;
}
}
public class Director {
/**
* Director 负责构建product
*/
private Builder builder = null;
public Director(Builder builder) {
this.builder = builder;
}
public void construct(String board, String display) {
builder.buildBoard(board);
builder.buildDisplay(display);
builder.buildOs();
}
}
public class Test {
public static void main(String[] args) {
Builder builder = new MacbookBuilder();
Director director = new Director(builder);
director.construct("英特尔", "25寸");
System.out.println(builder.create().toString());
}
}
在实际的Android开发中,我们一般这样应用
Person person = new Person.Builder().setName("test").......set.....build();
public class Person {
private String name;//用户不知道有哪些参数(参数太多)
public Person(Builder builder) {
name = builder.name;
}
public static class Builder {
private String name;
public Builder setName(String str) {
name = str;
return this;
}
public Person build() {
return new Person(this);
}
}
}