工厂方法配置bean

1：静态工厂方法配置bean

1）：对象

package com.spring.helloworld;

public class Car {
    private String name;
    private double jia;
    public void setName(String name) {
        this.name = name;
    }
    public void setJia(double jia) {
        this.jia = jia;
    }

    @Override
    public String toString() {
        return "Car [name=" + name + ", jia=" + jia + "]";
    }
    public Car(String name, int jia) {
        super();
        this.name = name;
        this.jia = jia;
    }
    
    
}

2）：静态工厂方法

package com.spring.helloworld;

import java.util.HashMap;
import java.util.Map;

public class StaticCarFactory {
    
    private static Map<String ,Car> cars=new HashMap<String,Car>();
    static{
        cars.put("audi", new Car("audi",30000));
        cars.put("ford", new Car("ford",40000));
        
    }
    public static Car getCar(String name){
        return cars.get(name);
    }
}

3）：配置文件

<!-- 
        class属性：指向静态工厂方法的全类名
        factory-method：指向静态工厂方法的名称
        constructor-arg：如果工厂方法需要传入参数，则使用构造器配置参数
     -->
    <bean id="car" class="com.spring.helloworld.StaticCarFactory"
    factory-method="getCar">
    <constructor-arg value="ford"></constructor-arg>
    </bean>

2：实例工厂方法

package com.spring.helloworld;

import java.util.HashMap;
import java.util.Map;

public class InstanceCarFactory {
    
    private  Map<String ,Car> cars=null;
    public InstanceCarFactory(){
        cars=new HashMap<String,Car>();
        cars.put("audi", new Car("audi",30000));
        cars.put("ford", new Car("ford",30000));
        
    }
    public  Car getCar(String name){
        return cars.get(name);
    }
}

<!-- 配置工厂的实例 -->
    <bean id="carFactory" class="com.spring.helloworld.InstanceCarFactory"></bean>
    <!-- 通过实例工厂方法来配置bean
        factory-bean：指向实例工厂方法的全类名
        factory-method：指向静态工厂方法的名字
        constructor-arg：如果工厂方法需要传入参数，则使用构造器配置参数
     -->
    <bean id="car" 
    factory-bean="carFactory" factory-method="getCar">
    <constructor-arg value="ford"></constructor-arg>
    </bean>