7- 实例化bean方式
7.1 项目结构
7.2无参数构造方法
7.2.1 配置bean.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd">
<bean id="customerService" class="cn.guardwhy.service.impl.CustomerServiceImpl"></bean>
<bean id="customerDao" class="cn.guardwhy.dao.impl.CustomerDaoImpl"
scope="singleton" init-method="init" destroy-method="destroy"></bean>
</beans>
7.3 使用静态工厂方法
7.3.1 编写静态工厂类
package cn.guardwhy.factory;
import cn.guardwhy.dao.CustomerDao;
import cn.guardwhy.dao.impl.CustomerDaoImpl;
public class StaticFactoryBean {
public static CustomerDao createCustomerDao(){
CustomerDao customerDao = null;
System.out.println("静态工厂方法实例化对象---------start");
customerDao = new CustomerDaoImpl();
System.out.println("静态工厂方法实例化对象----------end");
return customerDao;
}
}
7.3.2 配置bean.xml
<bean id="staticDao" class="cn.guardwhy.factory.StaticFactoryBean"
factory-method="createCustomerDao"></bean>
7.3.3 表现层
package cn.guardwhy.controller;
import cn.guardwhy.dao.CustomerDao;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class CustomerController {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
CustomerDao staticDao = (CustomerDao) context.getBean("staticDao");
staticDao.saveCustomer();
}
}
7.3.4 执行结果
7.4 使用实例工厂方法
7.4.1 编写工厂类
package cn.guardwhy.factory;
import cn.guardwhy.dao.CustomerDao;
import cn.guardwhy.dao.impl.CustomerDaoImpl;
public class InstanceFactoryBean {
public CustomerDao createCustomerDao(){
CustomerDao customerDao = null;
System.out.println("实例工厂方法实例化对象--------start");
customerDao = new CustomerDaoImpl();
System.out.println("实例工厂方法实例化对象--------end");
return customerDao;
}
}
7.4.2 配置bean.xml
<bean id="instanceFactory" class="cn.guardwhy.factory.InstanceFactoryBean"></bean>
<bean id="instanceDao" factory-bean="instanceFactory"
factory-method="createCustomerDao"></bean>
7.4.3 表现层(Controller)
package cn.guardwhy.controller;
import cn.guardwhy.dao.CustomerDao;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class CustomerController {
public static void main(String[] args) {
ApplicationContext context = new ClassPathXmlApplicationContext("bean.xml");
CustomerDao instanceDao = (CustomerDao) context.getBean("instanceDao");
instanceDao.saveCustomer();
}
}
7.4.4 操作结果