Ioc容器装配Bean的方法

wangteng

2015-12-15

一、基于XML的方法

1.属性的注入

<bean id="car" class="com.baobaotao.ditype.Car">
		<property name="brand" value="红旗&amp;CA72"/>
		<property name="maxSpeed" value="200"/>
		<property name="price" value="20000.00"/>
	</bean>
	<bean id="boss" class="com.baobaotao.ditype.Boss">
		<property name="car" ref="car"/>
	</bean>

也可以用简写的方式：

<bean id="car" class="com.baobaotao.ditype.Car"
      p:brand="红旗&amp;CA72"
      p:maxSpeed="200"
      p:price="20000.00"/>
  <bean id="boss" class="com.baobaotao.ditype.Boss"
	  p:car-ref="car"/>

有字面值属性：

<bean id="car" class="com.baobaotao.attr.Car" lazy-init="default">
		<property name="brand">
			<value>
				<![CDATA[红旗&CA72]]>
			</value>
		</property>
		<property name="maxSpeed">
			<value>200</value>
		</property>
		<property name="price" value="2000.00" />
	</bean>

2.构造函数注入

根据type

<bean id="car1" class="com.baobaotao.ditype.Car">
		<constructor-arg type="java.lang.String">
			<value>红旗CA72</value>
		</constructor-arg>
		<constructor-arg type="double">
			<value>20000</value>
		</constructor-arg>
	</bean>

根据index

<bean id="car2" class="com.baobaotao.ditype.Car">
		<constructor-arg index="0" value="红旗CA72" /> 
		<constructor-arg index="1" value="中国一汽" />
		<constructor-arg index="2" value="20000" />
	</bean>

根据type和index

<bean id="car3" class="com.baobaotao.ditype.Car">
		<constructor-arg index="0" type="java.lang.String">
			<value>红旗CA72</value>
		</constructor-arg>
		<constructor-arg index="1" type="java.lang.String">
			<value>中国一汽</value>
		</constructor-arg>
		<constructor-arg index="2" type="int">
			<value>200</value>
		</constructor-arg>
	</bean>

3.工厂方法注入

<bean id="carFactory" class="com.baobaotao.ditype.CarFactory" />
     <bean id="car5" factory-bean="carFactory" factory-method="createHongQiCar">
      </bean>

4.内部Bean

<bean id="boss2" class="com.baobaotao.attr.Boss">
		<property name="car">
			<bean class="com.baobaotao.attr.Car">
				<property name="maxSpeed" value="200" />
				<property name="price" value="2000.00" />
			</bean>
		</property>
	</bean>

5.继承类

<bean id="parentBoss" abstract="true"
		class="com.baobaotao.attr.Boss">
		<property name="favorites">
			<set>
				<value>看报</value>
				<value>赛车</value>
				<value>高尔夫</value>
			</set>
		</property>
	</bean>
	<bean id="childBoss" parent="parentBoss">
		<property name="favorites">
			<set merge="true">
				<value>爬山</value>
				<value>游泳</value>
			</set>
		</property>
	</bean>

6.集合类

<bean id="boss1" class="com.baobaotao.attr.Boss">
		<property name="car" ref="car" />
		<property name="favorites1">
			<set>
				<value>看报</value>
				<value>赛车</value>
				<value>高尔夫</value>
			</set>
		</property>
		<property name="favorites2">
			<list>
				<value>看报</value>
				<value>赛车</value>
				<value>高尔夫</value>
			</list> 
		</property>
		<property name="jobs">
			<map>
				<entry >
					<key>
						<value>AM</value>
					</key>
					<value>会见客户</value>
				</entry>
				<entry>
					<key>
						<value>PM</value>
					</key>
					<value>公司内部会议</value>
				</entry>
			</map>
		</property>
		<property name="mails">
			<props>
				<prop key="jobMail">[email protected]</prop>
				<prop key="lifeMail">[email protected]</prop>
			</props>
		</property>
	</bean>

7.FactoryBean

Java Bean

package com.baobaotao.fb;

import org.springframework.beans.factory.FactoryBean;

public class CarFactoryBean implements FactoryBean<Car> {

	private String carInfo;
	public String getCarInfo() {
		return carInfo;
	}

	public void setCarInfo(String carInfo) {
		this.carInfo = carInfo;
	}

	public Car getObject() throws Exception {
		Car car = new Car();
		String[] infos = carInfo.split(",");
		car.setBrand(infos[0]);
		car.setMaxSpeed(Integer.parseInt(infos[1]));
		car.setPrice(Double.parseDouble(infos[2]));
		return car;
	}

	public Class<Car> getObjectType() {
		return Car.class;
	}

	public boolean isSingleton() {
		return false;
	}
}

XML

<bean id="car1" class="com.baobaotao.fb.CarFactoryBean"
	      p:carInfo="红旗CA72,200,20000.00"/>

8.properties读取

<context:property-placeholder
		 location="classpath:com/baobaotao/placeholder/jdbc.properties"/>
	<context:component-scan base-package="com.baobaotao.beanprop"/>	 
	<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
		destroy-method="close" 
		p:driverClassName="${driverClassName}" 
		p:url="${url}"
		p:username="${userName}" 
		p:password="${password}" />

二、基于注解的方法

java类使用下面的注解：

@Component

@Repository

@Service

@Controller

package com.baobaotao.anno;

import org.springframework.beans.factory.BeanNameAware;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.stereotype.Service;

@Scope("session")
@Service
public class LogonService implements BeanNameAware{
	@Autowired(required=false)
	private LogDao logDao;
	@Autowired
	@Qualifier("userDao")
	private UserDao userDao;
	
	public LogDao getLogDao() {
		return logDao;
	}
	public UserDao getUserDao() {
		return userDao;
	}
	
	public void setBeanName(String beanName) {
		System.out.println("beanName:"+beanName);		
	}
	
	public void initMethod1(){
		System.out.println("initMethod1");
	}
	public void initMethod2(){
		System.out.println("initMethod2");
	}
//	@Autowired
//	public void setLogDao(LogDao logDao) {
//		this.logDao = logDao;
//	}
//	
//	@Autowired
//	@Qualifier("userDao")
//	public void setUserDao(UserDao userDao) {
//		System.out.println("auto inject");
//		this.userDao = userDao;
//	}
//	@Autowired
//	public void init(@Qualifier("userDao")UserDao userDao,LogDao logDao){
//		System.out.println("multi param inject");
//		this.userDao = userDao;
//		this.logDao =logDao;
//	}
	
}

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" 
	xmlns:context="http://www.springframework.org/schema/context"
	xsi:schemaLocation="http://www.springframework.org/schema/beans 
         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context-3.0.xsd"
         >
   <context:component-scan base-package="com.baobaotao.anno"/>
   <bean class="com.baobaotao.anno.LogonService"></bean>

   <!--
   <context:component-scan base-package="com.baobaotao" resource-pattern="anno/*.class"/>
   <context:component-scan base-package="com.baobaotao">
       <context:include-filter type="regex" expression="com\.baobaotao\.anno.*Dao"/>
       <context:include-filter type="regex" expression="com\.baobaotao\.anno.*Service"/>
       <context:exclude-filter type="aspectj" expression="com.baobaotao..*Controller+"/>
   </context:component-scan>


   <context:component-scan base-package="com.baobaotao">
       <context:include-filter type="aspectj" expression="com.baobaotao.anno.*Plugin+"/>
       <context:include-filter type="aspectj" expression="com.baobaotao.anno.MyComponent"/>
   </context:component-scan>
   -->	
</beans>

三、基于java类的配置

Spring提供一个AnnotationConfigApplicationContext类，它能够直接通过标注@Configuration的Java类启动Spring容器：

Java Code:

package com.baobaotao.conf;

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class JavaConfigTest {
	public static void main(String[] args) {
		
//1.通过构造函数加载配置类		
//         ApplicationContext ctx = new AnnotationConfigApplicationContext(AppConf.class);

//2.通过编码方式注册配置类
//		 AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
//		 ctx.register(DaoConfig.class);
//		 ctx.register(ServiceConfig.class);
//		 ctx.refresh();

//3.通过XML组装@Configuration配置类所提供的配置信息
//		 ApplicationContext ctx = new ClassPathXmlApplicationContext("com/baobaotao/conf/beans2.xml");

//4.通过@Configuration组装XML配置所提供的配置信息
//		 ApplicationContext ctx = new AnnotationConfigApplicationContext(LogonAppConfig.class);

		//5.@Configuration的配置类相互引用
		 ApplicationContext ctx = new AnnotationConfigApplicationContext(DaoConfig.class,ServiceConfig.class);
         LogonService logonService = ctx.getBean(LogonService.class);
         System.out.println((logonService.getLogDao() !=null));
         logonService.printHelllo();   
	}
}

DaoConfig java code:

package com.baobaotao.conf;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Scope;

@Configuration
public class DaoConfig {
    
	
	@Bean(name="")
	public UserDao userDao(){
		return new UserDao();
	}
	
	@Scope("prototype")
	@Bean
	public LogDao logDao(){
		return new LogDao();
	}
}

ServiceConfig java code:

package com.baobaotao.conf;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Import;
import org.springframework.context.annotation.ImportResource;

@Configuration
@Import(DaoConfig.class)
public class ServiceConfig {
	
    @Autowired
	private DaoConfig daoConfig;
    
	@Bean
	public LogonService logonService(){
		LogonService logonService = new LogonService();
		System.out.println(daoConfig.logDao() == daoConfig.logDao());
		logonService.setLogDao(daoConfig.logDao());
		logonService.setUserDao(daoConfig.userDao());
		return logonService;
	}
}

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" 
	xmlns:context="http://www.springframework.org/schema/context"
	xsi:schemaLocation="http://www.springframework.org/schema/beans 
         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
         http://www.springframework.org/schema/context
         http://www.springframework.org/schema/context/spring-context-3.0.xsd">
	<context:component-scan base-package="com.baobaotao.conf"
		resource-pattern="AppConf.class" />
</beans>

四、三种方式的比较

XML

注解

Java类

适合场景

1.Bean实现类来源于第三方类库，如Datasource、JdbcTemplete、HibernateTemplate等；

2.命名空间的配置，如aop、context等

Bean的实现类是当前项目开发的，可以直接在Java类中使用基于注解的配置，如DAO,Service,Controller类

通过代码的方式控制Bean初始化的整体，实例化Bean的逻辑比较复杂的情况

bean 容器