spring中PropertyPlaceholderConfigurer的运用---使用${property-name}取值
代码如下：
配置文件：
jdbc.properties的代码如下：
1 jdbc.driverClassName=org.hsqldb.jdbcDriver 2 jdbc.url=jdbc:hsqldb:hsql://production:9002 3 jdbc.username=sa 4 jdbc.password=root
applicationContext-properties-placeholder.xml 代码如下：
1 <?xml version="1.0" encoding="UTF-8"?> 2 <beans xmlns="http://www.springframework.org/schema/beans" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xmlns:p="http://www.springframework.org/schema/p" 5 xmlns:c="http://www.springframework.org/schema/c" 6 xmlns:aop="http://www.springframework.org/schema/aop" 7 xsi:schemaLocation="http://www.springframework.org/schema/beans 8 http://www.springframework.org/schema/beans/spring-beans.xsd 9 http://www.springframework.org/schema/aop 10 http://www.springframework.org/schema/aop/spring-aop.xsd"> 11 12 <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> 13 <property name="locations" value="classpath:jdbc.properties"/> 14 </bean> 15 <bean id="dataSource" destroy-method="close" 16 class="org.apache.commons.dbcp.BasicDataSource"> 17 <property name="driverClassName" value="${jdbc.driverClassName}"/> 18 <property name="url" value="${jdbc.url}"/> 19 <property name="username" value="${jdbc.username}"/> 20 <property name="password" value="${jdbc.password}"/> 21 </bean> 22 </beans>
上面的红色部分均按照：${property-name}取值.
测试类的代码如下：
package com.timo.test; import org.apache.commons.dbcp.BasicDataSource; import org.springframework.context.support.ClassPathXmlApplicationContext; public class Test19 { public static void main(String[] args) { ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext-properties-placeholder.xml"); BasicDataSource dataSource = applicationContext.getBean(BasicDataSource.class); System.out.println("driverClassName="+dataSource.getDriverClassName()); } }
上面xml配置文件中
<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="locations" value="classpath:jdbc.properties"/>
</bean>
等效于
<context:property-placeholder location="classpath:jdbc.properties"/>
