Spring PropertyPlaceholderConfigurer不注入值

Question

I've already spent several hours googling but still can do nothing.

Using debugger, I can find out that user and password in my datasource are not replaced with values from properties file, but parsed as is like ${jdbc.user} and ${jdbc.password} respectively.

What am I doing wrong?

This is jdbc.properties file (located at src/main/resources):

jdbc.username=user
jdbc.password=password

And here's spring configuration xml:

<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="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="location">
        <value>jdbc.properties</value>
    </property>
</bean>

...

And that's dependency from pom.xml:

<dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>3.0.5.RELEASE</version>
</dependency>

Answer 1

The problem is the way you launch your application.

XmlBeanFactory parent = new XmlBeanFactory(new ClassPathResource("Parent.xml",SomeClass.class)); 
final XmlBeanFactory springBeanFactory = new XmlBeanFactory(new ClassPathResource(getClass().getSimpleName() + ".xml", getClass()), parent); 

Don't use a BeanFactory use an ApplicationContext .

String context = getClass().getSimpleName() + ".xml";
ApplicationContext parent = new ClassPathXmlApplicationContext("Parent.xml");
ApplicationContext child = new ClassPathXmlApplicationContext(new String[] {context}, parent);

A BeanFactory is just a factory for beans, nothing more nothing less. The ApplicationContext is a BeanFactory on steroids. It has a complete lifecycle and has special types of beans that are called during that lifeccycle.

Check this section of the reference guide.

Another tip, use the namespace to configure the placeholder support instead of the bean declaration and it is always wise to prefix it with from where/how you want it to be loaded.

<context:property-placeholder location="classpath:/jdbc.properties" />

A final word on the placeholder support. This class is a BeanFactoryPostProcessor and it will process bean definitions and replace the placeholders in them. However it does this only for beans in the same application context!. If you defined this bean in the parent and expect it to replace placeholders in the child context then that isn't going to happen.

Answer 2

You need to tell Spring to search the classpath for the properties file, otherwise it will not be able to find it. Change the property file location from jdbc.properties to classpath:/jdbc.properties .

Answer 3

Try this resolver instead:

<bean class="org.springframework.context.support.PropertySourcesPlaceholderConfigurer">
    <property name="locations">
        <list>
            <value>classpath:jdbc.properties</value>
        </list>
    </property>
</bean>