学习 Spring (六) 自动装配
Spring入门篇 学习笔记
- No: (默认)不做任何操作
- byName: 根据属性名自动装配。此选项将检查容器并根据名字查找与属性完全一致的 bean，并将其与属性自动装配
- byType: 如果容器中存在一个与指定属性类型相同的 bean，那么将与该属性自动装配；如果存在多个该类型的 bean，那么抛出异常，并指出不能使用 byType 方式进行自动装配；如果没有找到相匹配的 bean，则什么事都不发生
- constructor: 与 byType 方式类似，不同之处在于它应用于构造器参数。如果容器中没有找到与构造器参数类型一致的 bean 则抛出异常
准备工作，添加 AutoWiringDAO：
public class AutoWiringDAO {
public void say(String word) {
System.out.println("AutoWiringDAO : " + word);
}
}
byName
添加 AutoWiringServiceByName：
public class AutoWiringServiceByName {
private AutoWiringDAO autoWiringDAO;
public void setAutoWiringDAO(AutoWiringDAO autoWiringDAO) {
this.autoWiringDAO = autoWiringDAO;
}
public void say(String word) {
this.autoWiringDAO.say(word);
}
}
添加配置文件 spring-autowiring-byname.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"
default-autowire="byName">
<bean id="autoWiringService" class="com.karonda.autowiring.AutoWiringServiceByName" ></bean>
<bean id="autoWiringDAO" class="com.karonda.autowiring.AutoWiringDAO" ></bean>
</beans>
添加测试类：
@RunWith(BlockJUnit4ClassRunner.class)
public class TestAutoWiringByName extends UnitTestBase {
public TestAutoWiringByName() {
super("classpath:spring-autowiring-byname.xml");
}
@Test
public void testSay() {
AutoWiringServiceByName service = super.getBean("autoWiringService");
service.say(" this is a test");
}
}
byType
添加 AutoWiringServiceByType：
public class AutoWiringServiceByType {
private AutoWiringDAO autoWiringDAO;
public void setAutoWiringDAO(AutoWiringDAO autoWiringDAO) {
this.autoWiringDAO = autoWiringDAO;
}
public void say(String word) {
this.autoWiringDAO.say(word);
}
}
添加配置文件 spring-autowiring-bytype.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"
default-autowire="byType">
<bean id="autoWiringService" class="com.karonda.autowiring.AutoWiringServiceByType" ></bean>
<bean class="com.karonda.autowiring.AutoWiringDAO" ></bean>
</beans>
添加测试类：
@RunWith(BlockJUnit4ClassRunner.class)
public class TestAutoWiringByType extends UnitTestBase {
public TestAutoWiringByType() {
super("classpath:spring-autowiring-bytype.xml");
}
@Test
public void testSay() {
AutoWiringServiceByType service = super.getBean("autoWiringService");
service.say(" this is a test");
}
}
constructor
添加 AutoWiringServiceConstructor
public class AutoWiringServiceConstructor {
private AutoWiringDAO autoWiringDAO;
public AutoWiringServiceConstructor(AutoWiringDAO autoWiringDAO){
this.autoWiringDAO = autoWiringDAO;
}
public void say(String word) {
this.autoWiringDAO.say(word);
}
}
添加配置文件 spring-autowiring-constructor.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"
default-autowire="constructor">
<bean id="autoWiringService" class="com.karonda.autowiring.AutoWiringServiceConstructor" ></bean>
<bean class="com.karonda.autowiring.AutoWiringDAO" ></bean>
</beans>
添加测试类：
@RunWith(BlockJUnit4ClassRunner.class)
public class TestAutoWiringConstructor extends UnitTestBase {
public TestAutoWiringConstructor() {
super("classpath:spring-autowiring-constructor.xml");
}
@Test
public void testSay() {
AutoWiringServiceConstructor service = super.getBean("autoWiringService");
service.say(" this is a test");
}
}
