Load and Inject to Property Bean from XML Property File with Spring

Question

I am trying to load SQL queries from an XML property file and inject it as a java.util.Property into my DAO class. The SQLs.xml resides in the same directory as the application context (I'm using Maven structure, so they all under src/main/resources). My application context file looks like following:

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"
xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:task="http://www.springframework.org/schema/task"
xmlns:util="http://www.springframework.org/schema/util"
xsi:schemaLocation="http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.2.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.2.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.2.xsd http://www.springframework.org/schema/task http://www.springframework.org/schema/task/spring-task-3.2.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-2.5.xsd">

<bean id="EmployeeDAO" class="pkg.dao.EmployeeDAOImpl">
    <property name="dataSource" ref="dataSource" />
</bean>

<bean id="dataSource"
    class="org.springframework.jdbc.datasource.DriverManagerDataSource">

    <property name="driverClassName" value="oracle.jdbc.OracleDriver" />
    <property name="url" value="oracle jdbc url" />
    <property name="username" value="username" />
    <property name="password" value="password" />
</bean>

<util:properties id="queryProps" location="classpath:SQLs.xml"/>

<bean id="employeeDAOProp" class="pkg.dao.EmployeeDAOImpl">
    <property name="queryProps" ref="queryProps" />
</bean>

And the SQLs.xml content is:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">

<properties>

    <entry key="getEmployee">
      select * from employee;
    </entry>

</properties>

The DAO class:

public class EmployeeDAO {

  private DataSource dataSource;
  private Properties queryProps;

  public Properties getQueryProps() {
    return queryProps;
  }

  public void setQueryProps(Properties queryProps) {
    this.queryProps = queryProps;
  }

  public void setDataSource(DataSource dataSource) {
    this.dataSource = dataSource;
  }

  public Employee getEmployee(int id) {
    String sql = queryProps.getProperty("getEmployee");
  }
}

I am loading the context file in the Main application with:

ConfigurableApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");

I can load the EmployeeDAO without an issue and call on its getEmployee() method. Even the datasource pulls all the needed key/values without an issue. But the queryProps is always null.

Answer 1

It appears that I was injecting the properties into two different instances.

    <util:properties id="queryProps" location="classpath:SQLs.xml"/>  
    <bean id="EmployeeDAO" class="pkg.dao.EmployeeDAOImpl">  
        <property name="dataSource" ref="dataSource" />  
        <property name="queryProps" ref="queryProps" />  
    </bean> 

Now the queryProps Property contains the expected content from the SQLs.xml.