Spring配置bean之静态工厂方法

通过静态工厂方法配置bean

注意：静态工厂方法配置bean不是配置静态工厂方法实例，而是配置bean实例

1. 首先建立car类，设置brand，price两个属性

public class Car {
    
    private String brand;
    private int price;

    public String getBrand() {
        return brand;
    }

    public void setBrand(String brand) {
        this.brand = brand;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "Car{" +
                "brand='" + brand + '\'' +
                ", price=" + price +
                '}';
    }

    public Car() {
        System.out.println("car's constructor...");

    }

    public Car(String brand, int price) {
        super();
        this.brand = brand;
        this.price = price;
    }

2. 再建立StaticCarFactory类

public class StaticCarFactory {

    private static Map<String, Car> cars = new HashMap<String, Car>();

    static {
        cars.put("audi", new Car("audi", 3000000));
        cars.put("ford", new Car("ford", 4000000));
    }

    //静态工厂方法
    public static Car getCar(String name) {

        return cars.get(name);

    }

3. 在建立beans-factory.xml配置bean

<!--通过静态工厂方法来配置bean，注意不是配置静态工厂方法实例，而是配置bean实例-->
    <!--
        class 属性：指向静态工厂方法的全类名
        factory-method: 指向静态方法的名字
        constructor-arg:如果工厂方法需要传入参数，则使用constructor-arg来配置参数
    -->
    <bean id="car1"
        class="com.sofia.spring.beans.factory.StaticCarFactory"
        factory-method="getCar">
        <constructor-arg value="audi"/>
    </bean>

4. 最后在主函数中创建容器，输出就可以啦！

ApplicationContext ctx = new ClassPathXmlApplicationContext("beans-factory.xml");
        Car car1 = (Car) ctx.getBean("car1");
        System.out.println(car1);