I am trying to load a properties file into a Spring bean and then inject that bean into a cl开发者_运维技巧ass.
The only part I can't get to work seems to be using the @Resource reference.Can someone connect the last piece for me? I get a null value every time. Doesn't seem to want to inject the value.
[EDIT] - I originally thought using the @Resource was the best way but the proposed solution I found easier.
I saw this solution in another post:
Reference Solution Link: Inject Property Value into Spring - posted by DON
Credit to Don for the post but I just wasn't sure how to finish it with the @Resource.
Debugging Results:
The variable value appProperties
is always null. It's not being injected.
Spring Config.
Sample Class:
package test;
import java.util.Properties;
import javax.annotation.Resource;
public class foo {
public foo() {}
@Resource private java.util.Properties appProperties;
}
Based on the advice in the approved solution below. Here are the changes I made.
Solution Update:
Spring Config:
Java Class:
For your solution to work you would also need to make foo a Spring managed bean; because otherwise how would Spring know that it has to deal with any of your annotations on your class?
- You can either specify it in your appcontext xml as a bean with
..class="foo"
- Or use
component-scan
and specify a base package which contains yourfoo
class.
Since I'm not entirely sure this is exactly what you want (don't you want a .properties file to be parsed by Spring and have it's key-value pairs available instead of a Properties
object?), I'm suggesting you another solution: Using the util
namespace
<util:properties id="props" location="classpath:com/foo/bar/props.properties"/>
And reference the values inside your beans (also, have to be Spring managed):
@Value("#{props.foo}")
public void setFoo(String foo) {
this.foo = foo;
}
EDIT:
just realized that you are importing org.springframework.context.ApplicationContext
in your class which is probably unnecessary. I strongly encourage you to read Spring reference at least the first few chapters, because a) it's a great read b) you will find it much easier to understand Spring if the basics are clear.
Just one more solution using properties placeholder.
The spring context:
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-3.1.xsd">
<context:component-scan base-package="your.packege" />
<context:property-placeholder location="classpath*:*.properties"/>
</beans>
The java class where you want inject properties values:
public class ClassWithInjectedProperty {
@Value("${props.foo}")
private String foo;
}
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