基于XML的DI容器配置元数据

深藏阁楼爱情的钟 2022-08-06 11:17 159阅读 0赞

**一、定义POJO类**

package test; /\*\* \* IHelloStr接口 \* \* @author zxs \*/ public interface IHelloStr \{ public String getContent(); \}

package test; import java.io.InputStream; import java.util.Properties; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /\*\* \* 基于文件形式，读取HelloWorld所需的字符串。 \* \* @author zxs \*/ public class FileHelloStrImpl implements IHelloStr \{ protected static final Log log = LogFactory.getLog(FileHelloStrImpl.class); private String propfilename; public FileHelloStrImpl(String propfilename) \{ this.propfilename = propfilename; \} public String getContent() \{ String helloworld = ""; try \{ Properties properties = new Properties(); //读入输入流 InputStream is = getClass().getClassLoader().getResourceAsStream( propfilename); properties.load(is); is.close(); //获得helloworld键对应的取值 helloworld = properties.getProperty("helloworld"); \} catch (Exception ex) \{ log.error("", ex); \} return helloworld; \} \}

package test; /\*\* \* IHelloWorld接口 \* \* @author zxs \* \*/ public interface IHelloWorld \{ public abstract String getContent(); \}

package test; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /\*\* \* 获得HelloWorld字符串 \* \* @author zxs \*/ public class HelloWorld implements IHelloWorld \{ protected static final Log log = LogFactory.getLog(HelloWorld.class); private IHelloStr helloStr; public void setHelloStr(IHelloStr str) \{ this.helloStr = str; \} public String getContent() \{ return helloStr.getContent(); \} \}

**二、将上述两个POJO配置在基于XML Schema的Spring XML文件中（beanfactory.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-2.5.xsd"> <bean name="fileHello" class="test.FileHelloStrImpl"> <constructor-arg> <value>helloworld.properties</value> </constructor-arg> </bean> <bean id="helloWorld" class="test.HelloWorld"> <property name="helloStr" ref="fileHello" /> </bean> </beans>

**三、构造IoC容器，负责装载上述XML文件**

package test; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.beans.factory.BeanFactory; import org.springframework.beans.factory.xml.XmlBeanFactory; import org.springframework.core.io.ClassPathResource; import org.springframework.core.io.Resource; /\*\* \* HelloWorld客户应用 \* \* @author zxs \*/ public class BeanFactoryDemo \{ protected static final Log log = LogFactory.getLog(BeanFactoryDemo.class); public static void main(String\[\] args) \{ //从classpath路径上装载XML配置信息 Resource resource = new ClassPathResource("beanfactory.xml"); //实例化IoC容器，此时，容器并未实例化beanfactory.xml所定义的各个受管Bean BeanFactory factory = new XmlBeanFactory(resource); //获得受管Bean IHelloWorld hw = (IHelloWorld) factory.getBean("helloWorld"); //返回字符串 log.info(hw.getContent()); \} \}