Spring 配置文件的一般结构如下：
• <beans> • <import resource = “ resource1.xml ” /> • <import resource =“resource2.xml” /> • <bean id=“bean1” class=“ *** ”></bean> • <bean name= “ bean2” class= “ *** ”></bean> • <alias alias= “ bean3 ” name= “ bean2 ” /> • </beans> 其中import是导入其他配置。
以上实例代码为：
1、命名
首先是接口类：
public interface HelloWorld { public void sayHello(); }然后是实现类：
public class HelloWorldImpl implements HelloWorld { @Override public void sayHello() { System.out.println("Hello World!"); } }spring命名实例：
<?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-3.0.xsd"> <bean class="com.jike.spring.chapter04.definition.HelloWorldImpl" /> <bean id="helloWorld" class="com.jike.spring.chapter04.definition.HelloWorldImpl" /> <bean name="helloWorldByName" class="com.jike.spring.chapter04.definition.HelloWorldImpl" /> <bean id="helloWorldById" name="helloWorldByName01" class="com.jike.spring.chapter04.definition.HelloWorldImpl" /> <bean name="bean1;alias11;alias12;alias13" class="com.jike.spring.chapter04.definition.HelloWorldImpl" /> <bean id="bean2" name="alias21,alias22,alias23" class="com.jike.spring.chapter04.definition.HelloWorldImpl" /> <bean name="bean3" class="com.jike.spring.chapter04.definition.HelloWorldImpl" /> <alias alias="alias31" name="bean3" /> <alias alias="alias32" name="bean3" /> </beans> 2、实例化示例代码
首先是接口类：
public interface HelloWorld { public void sayHello(); }实现类：
public class HelloWorldImpl implements HelloWorld { private String message; /** * 空构造器 */ public HelloWorldImpl() { this.message = "Hello World!"; } /** * 带参构造器 * * @param message */ public HelloWorldImpl(String message) { this.message = message; } public void sayHello() { System.out.println(message); } }构造器实例化不需要类。 下面是静态工厂实例化类：
public class HelloWorldStaticFactory { /** * 工厂方法 * * @param message * @return */ public static HelloWorld newInstance(String message) { // 返回需要的Bean实例 return new HelloWorldImpl(message); } }下面是实例工厂实例化类：
public class HelloWorldInstanceFactory { /** * 工厂方法 * * @param message * @return */ public HelloWorld newInstance(String message) { // 返回需要的Bean实例 return new HelloWorldImpl(message); } }最后是实例化的spring配置文件：
<?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-3.0.xsd"> <!--使用默认构造参数--> <bean id="helloWorldWithNoArgs" class="com.jike.spring.chapter04.instance.HelloWorldImpl" /> <!--使用有参数构造参数--> <bean id="helloWorldWithArgs" class="com.jike.spring.chapter04.instance.HelloWorldImpl" > <!-- 指定构造器参数 --> <constructor-arg index="0" value="Hello Args!"/> </bean> <!--静态工厂方式--> <bean id="helloWorldStaticFactory" class="com.jike.spring.chapter04.instance.HelloWorldStaticFactory" factory-method="newInstance" > <!-- 指定构造器参数 --> <constructor-arg index="0" value="Hello Static Factory!"/> </bean> <!-- 1、定义实例工厂Bean --> <bean id="helloWorldInstanceFactory" class="com.jike.spring.chapter04.instance.HelloWorldInstanceFactory" /> <!-- 2、使用实例工厂Bean创建Bean --> <bean id="helloWorldInstance" factory-bean="helloWorldInstanceFactory" factory-method="newInstance"> <constructor-arg index="0" value="Hello Instance Factory!"></constructor-arg> </bean> </beans> 最后是测试代码：
import org.springframework.beans.factory.BeanFactory; import org.springframework.context.support.ClassPathXmlApplicationContext; public class Main { public static void main(String[] args) { helloWorldInstanceFactory(); } //使用无参数构造器来实例化Bean public static void sayHelloWithNoArgs() { BeanFactory beanFactory = new ClassPathXmlApplicationContext("conf/conf-instance.xml"); HelloWorld helloWorld = beanFactory.getBean("helloWorldWithNoArgs", HelloWorld.class); helloWorld.sayHello(); } //使用有参数构造器来实例化Bean public static void sayHelloWithArgs() { BeanFactory beanFactory = new ClassPathXmlApplicationContext("conf/conf-instance.xml"); HelloWorld helloWorld = beanFactory.getBean("helloWorldWithArgs", HelloWorld.class); helloWorld.sayHello(); } //使用静态工厂方法来实例化Bean public static void helloWorldStaticFactory() { // 1、读取配置文件实例化一个IOC容器 BeanFactory beanFactory = new ClassPathXmlApplicationContext("conf/conf-instance.xml"); // 2、从容器中获取Bean，注意此处完全“面向接口编程，而不是面向实现” HelloWorld helloWorld = beanFactory.getBean("helloWorldStaticFactory", HelloWorld.class); // 3、执行业务逻辑 helloWorld.sayHello(); } //使用实例化工厂方法来实例化Bean public static void helloWorldInstanceFactory() { // 1、读取配置文件实例化一个IOC容器 BeanFactory beanFactory = new ClassPathXmlApplicationContext("conf/conf-instance.xml"); // 2、从容器中获取Bean，注意此处完全“面向接口编程，而不是面向实现编程” HelloWorld helloWorld = beanFactory.getBean("helloWorldInstance", HelloWorld.class); // 3、执行业务逻辑 helloWorld.sayHello(); } }
