从零开始-上下文错误：属性占位符

Question

I'm doing some test on a very, very simple application using Spring .

My app have only have one bean and I'm injecting a simple String to this class and printing this value. So far all working .

---

What I need:

I want to get this String from a configuration file, so I create the file inside /src/main/resource

What I did:

1) On my application-context.xml I add:

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

2) On my application-context.xml I change from the simple String to use ${name_test}:

<bean id="hello" class="com.dummy.SayHello">
    <property name="name" value="${name_test}" />
</bean>

3) I double check myConfigFile.properties and contains the "name_test=JackTheRipper"

4) But my output is not 'translating' the value from the config file, I have this output when I run my app:

Hello ${name_test}

And I'm stuck here, any clue, tips???

---

Just FYI

• I use THIS tutorial for my tests, maybe could help.
• I add the log4j maven dependencies and log4j config file and all works fine! So Spring and log4j are finding the files inside "src/main/resource"
• I'm using maven , and to run my app, I'm using:

  mvn clean compile exec:java

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SOLUTION EXPLANATION:

The root cause was how I was getting the application-context.xml on my java class.

I was doing:

BeanFactory factory = new XmlBeanFactory(new ClassPathResource("application-context.xml"));

and then after this post I change it to:

ApplicationContext context = new ClassPathXmlApplicationContext("application-context.xml");

• A good place to understand and read is HERE
• Thanks all for the help!

Answer 1

The only problem I can imagine here is that you use BeanFactory instead of ApplicationContext . Compared to ApplicationContext , BeanFactory misses some advanced features including automatic registration of postprocessors, that is necessary for <context:property-placeholder> .

Answer 2

Just for curiosity sake, instead of using <context:property-placeholder> , can you try this?

<bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="location">
        <value>classpath:myConfigFile.properties</value>
    </property>
</bean>

If that doesn't work, try putting a * after classpath :-

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

Answer 3

Your config is fine. My guess is that your properties file cannot be found on the classpath. Is there any Spring logging in regards to the configurer? Try running:

mvn clean install exec:java

This will create an artifact (jar), which will bundle your src/main/resources content, while compile obviously just compiles the source files to class files.

I might try a test case too. Add spring test to your pom:

POM

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-test</artifactId>
    <version>[YOUR SPRING VERSION]</version>
</dependency>
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.8</version>
</dependency>

Test

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations="classpath:application-context.xml")
public class TestSayHello
{
   @Autowired
   @Qualifier("hello")
   private SayHello hello;

   @Test
   public void testSayHello()
   {
      Assert.assertNotNull(hello);
      Assert.assertEquals("JackTheRipper", hello.getName());
   }
}

The no id or name message is just a warning since your bean doesn't contain either. If your config file could not be found, you should a message stating so as well.