spring创建工厂的三种方式

Posted 2020-11-28 惬意的小屋

基础代码
        ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
        People people = applicationContext.getBean("peo", People.class);
        System.out.println(people);

1. 构造方法（默认无参构造，可以有参构造）

无参构造
<bean id="peo" class="com.run.People"></bean>

有参构造
    <bean id="peo" class="com.run.People">
        <constructor-arg name="name" value="ych"></constructor-arg>
        <constructor-arg name="age" value="30"></constructor-arg>
    </bean>

1. 实例工厂

public class PeopleFactory {
    public People getPeople() {
        return new People();
    }
}

    <bean id="fac1" class="com.run.PeopleFactory"></bean>
    <bean id="peo" factory-bean="fac1" factory-method="getPeople"></bean>

1. 静态工厂

public class PeopleFactory {
    public static People getPeople1() {
        People people = new People();
        people.setName("ych");
        return people;
    }
}

<bean id="peo" class="com.run.PeopleFactory" factory-method="getPeople1"></bean>