Spring框架bean的配置(2):SpEL:引用 Bean、属性和方法。。。
将这些架包放入在工程目录下建立的lib文件夹里,并解压
commons-logging-1.1.1
spring-aop-4.0.0.RELEASE
spring-beans-4.0.0.RELEASE
spring-context-4.0.0.RELEASE
spring-core-4.0.0.RELEASE
spring-expression-4.0.0.RELEASE
1.SpEL,实现
Person类,其属性如下,其get,set,tostrong方法就不写了
private String name;
private Car car;
private String city;//city属性是引用了Address中city的属性
private String info;//根据car的price属性来确定info,price大于30万,不大于30万
car类,其属性如下,set,get,tostring方法就不写了
private String brand; private double price; private double tyrePerimeter;//轮胎的周长
address类,其属性如下,set,get,tostring方法就不下了
private String city; private String street;
建立spring bean configuration file文件:beans.xml
<!-- spEL的使用#{…} --> <bean id="address" class="com.atguigu.spring.beans.Address"> <property name="city" value="#{'BeiJing'}"></property> <property name="street" value="jianglingjialu"></property> </bean> <bean id="car" class="com.atguigu.spring.beans.Car"> <property name="brand" value="auti"></property> <property name="price" value="345566"></property> <property name="tyrePerimeter" value="#{T(java.lang.Math).PI * 30}"></property> </bean> <bean id="person" class="com.atguigu.spring.beans.Person"> <property name="name" value="#{'panpan'}"></property> <property name="car" value="#{car}"></property> <property name="city" value="#{address.city}"></property> <property name="info" value="#{car.price>300000 ? '金领' : '蓝领' }"></property> </bean>
在src目录下的Main类 测试方法;
ApplicationContext app=new ClassPathXmlApplicationContext("beans.xml"); Address address=(Address) app.getBean("address"); System.out.println(address); Car car=(Car) app.getBean("car"); System.out.println(car); Person person=(Person) app.getBean("person"); System.out.println(person);
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2.静态工厂方式,spring的bean的配置方法;
建立StaticCarFactory类:
package com.atguigu.spring.beans; import java.util.HashMap; import java.util.Map; public class StaticCarFactory { //静态工厂方式,spring的bean的配置方法 private static Map<String, Car> cars=new HashMap<String, Car>(); static{ cars.put("KKK", new Car("changan",423423,432.43)); cars.put("PPP", new Car("fute",42323,32.43)); } //在xml文件中,可以设置和获取getCar方法 public static Car getCar(String name){ return cars.get(name); } }
在beans.xml 文件中配置bean;
<!-- 静态工厂方式 --> <bean id="car1" class="com.atguigu.spring.beans.StaticCarFactory" factory-method="getCar"> <constructor-arg value="PPP"></constructor-arg> </bean>
在 Main类 中测试;
ApplicationContext app=new ClassPathXmlApplicationContext("beans.xml"); Car car1=(Car) app.getBean("car1"); System.out.println(car1);
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3.实例工厂的方法,实现bean的配置;
建立类:InstanceFactory
package com.atguigu.spring.beans; import java.util.HashMap; import java.util.Map; public class InstanceFactory { private Map<String, Car> cars=null; //实例工厂的方法 public InstanceFactory() { cars=new HashMap<String, Car>(); cars.put("KKK", new Car("luhu", 434233, 43.2)); cars.put("QQQ", new Car("fute", 656546, 45.4)); } public Car getCar(String brand){ return cars.get(brand); } }
在beans.xml 文件中配置bean;
<!-- 实例工厂的方式 -->
<bean id="factory" class="com.atguigu.spring.beans.InstanceFactory"></bean>
<bean id="car2" factory-bean="factory" factory-method="getCar">
<constructor-arg value="QQQ"></constructor-arg>
</bean>
在类Main中,测试:
ApplicationContext app=new ClassPathXmlApplicationContext("beans.xml"); Car car2=(Car) app.getBean("car2"); System.out.println(car2);
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4.FactoryBean的配置方法:继承接口:FactoryBean,泛型为Car;
package com.atguigu.spring.beans; import org.springframework.beans.factory.FactoryBean; //FactoryBean的配置方法 public class CarFactoryBean implements FactoryBean<Car>{ private String brand; public void setBrand(String brand) { this.brand = brand; } @Override //返回bean的对象,即car public Car getObject() throws Exception { return new Car(brand, 200000, 1.2); } @Override //返回bean的类型 public Class<?> getObjectType() { return Car.class; } @Override //是不是但实力的 public boolean isSingleton() { return true; } }
在beans.xml 文件中配置bean;
<!-- FactoryBean的配置方法 -->
<bean id="car3" class="com.atguigu.spring.beans.CarFactoryBean">
<property name="brand" value="panpan"></property>
</bean>
在类Main中,测试:
ApplicationContext app=new ClassPathXmlApplicationContext("beans.xml"); Car car3=(Car) app.getBean("car3"); System.out.println(car3);