How to access a properties file values in Spring 3?

[Mike London]

How to you wire and access property file values in, say, a domain class in a Spring 3 MVC application?

If you have some validation going on with @Size or @Pattern for the domain class fields, what if you want to have the error messages that get displayed to be from a properties file instead of being hard coded.

So, I'd like to be able to have something like:

 @Pattern(regexp="^[a-zA-Z0-9]+$",message="${myproperties.name}")(

where the message above comes from a properties file.

I don't see how to either inject this information or use a properties file directly.

The Spring documentation doesn't seem to have an example for this.

Would greatly appreciate help here.

Thanks very much in advance.

mike

[ntumba lobo]

Well if you load your property files with Spring, you can use a new annotation to inject value from property file in teh field of a Java class
Load the property file in the Spring Context with
<util:properties id="myProperties"
location="classpath:/myprops.properties" />

or
<bean id="propertyConfigurer"
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location" value=":/myprops.properties" />
</bean>

Then in a Java class

@Value("#{myProperties[myPropName]}")
private String myField;

or if you have only one property file

@Value("#{myPropName}")
private String myField;

Hope that helps

[Mike London]

ntumba lobo wrote:Well if you load your property files with Spring, you can use a new annotation to inject value from property file in teh field of a Java class
Load the property file in the Spring Context with
<util:properties id="myProperties"
location="classpath:/myprops.properties" />

or
<bean id="propertyConfigurer"
class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<property name="location" value=":/myprops.properties" />
</bean>

Then in a Java class

@Value("#{myProperties[myPropName]}")
private String myField;

or if you have only one property file

@Value("#{myPropName}")
private String myField;

Hope that helps

Wow, this is soooo close. THANK YOU!

However, from my code sample above, after I successfully declare the util in applicationContext.xml, if I try to do something like this:

	
@Value("#{errorProps[name]}")  
private String userNameRequired;

@Pattern(regexp = "^[a-zA-Z0-9]+$", message = "${errorProps[name]}")

in my domain class and then purposefully add some garbage characters.

Then, I just get the literal in the output #(errorProps[name])

That is, it's not de-referenced to show the actual message from the properties file.

The definition in the applicationContext.xml file is this:

<util:properties id="errorProps" location="/WEB-INF/properties/errors.properties" /> 

The "name" key in the properties file should print the message: "Name is required."

Any idea what's still wrong?

Is it possible that the message tag doesn't support what I'm trying to do?

thanks again for any other suggestions.

-mike

[ntumba lobo]

hum what if instead of

@Value("#{errorProps[name]}")
private String userNameRequired;

you try

@Value("#{errorProps.name}")
private String userNameRequired;

does it work better?

[Mike London]

ntumba lobo wrote:hum what if instead of

@Value("#{errorProps[name]}")
private String userNameRequired;

you try

@Value("#{errorProps.name}")
private String userNameRequired;

does it work better?

------

Unfortunately, no. I still just get the same ${userNameRequired} literal output.

I appreciate all your help. Not sure what's wrong here.

Perhaps it's that I defined the application context like this?

    <util:properties id="errorProps" location="/WEB-INF/properties/errors.properties" /> 

If I used the classpath notation like you did, I always got a FileNotFoundException.

The above "full path" seems to compile OK, but it doesn't appear to be getting injected.

I get 'null' for the injected property.

How could the injection itself not be working?

Here's my entire applicationContext.xml:

<?xml version="1.0" encoding="UTF-8"?>
<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:context="http://www.springframework.org/schema/context"
    xmlns:util="http://www.springframework.org/schema/util"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans 
        http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context-3.0.xsd
        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util-2.5.xsd">
        
        <bean class="org.springframework.web.servlet.mvc.annotation.DefaultAnnotationHandlerMapping"/>     
      
        <util:properties id="errorProps" location="/WEB-INF/properties/errors.properties" /> 
        
</beans>

[ntumba lobo]

I see so this is Spring that cant find your property file.
if you build your project with maven try putting your errors.properties under src/main/resources. After building the web app
it should end up under web-inf/lib.
In you spring config just use
<util:properties id="errorProps" location="classpath:errors.properties" />

This should work really.