How to get the property value inside a spring bean class in my class ?

Question

The things I did are:

Created a property file (data.properties).
Created a Spring.xml (I use property placeholder)
Created a bean class.
I have a class where I have to use the url value.
I have a web.xml which has context-param where i set the param value to the path of the Spring.xml file.
My codes are given below:

Propertyfile:url=sampleurl

Spring.xml:

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

</bean>

<bean id="dataSource" class="org.tempuri.DataBeanClass">
    <property name="url" value="${url}"></property>
</bean>

beanclass

public class DataBeanClass extends PropertyPlaceholderConfigurer{
private String url;

public String getUrl() {
    return url;
}

public void setUrl(String url) {
    this.url = url;
}
}

entry in web.xml

 <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath*:Spring*.xml</param-value>
</context-param>
<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

Now my problem is I dont know what method of PropertyPlaceholderConfigurer should I override and what should I do to set the value of variable url such that I can call it from other classes using getproperty() method.

The problem is that I was told that my bean class should extend some class and I should override one of its method so that I can use the property values in some other class. I assume the class to be extended is PropertyPlaceholderConfigurer. I am not 100% sure though. — antony.ouseph.k, Nov 14 '13 at 06:03
That doesn't make much sense to me. Ask for a requirement, don't ask for what to do, especially when it isn't clear what the expectation is. — Sotirios Delimanolis, Nov 14 '13 at 06:04
alright the requirement is that I should be able to use my url value in the bean class in any other classes. — antony.ouseph.k, Nov 14 '13 at 06:07
Do you want the value of "url" property in your property file, to be injected by spring into DataBeanClass objects url ? — Subin Sebastian, Nov 14 '13 at 06:07
since your "url" value is already present in property file, I think you want to use that property in multiple bean classes. — Subin Sebastian, Nov 14 '13 at 06:08
The value will be injected in your DataBeanClass without extending PropertyPlaceholderConfigurer itself. The configuration which you've done already looks sufficient. — Karthik, Nov 14 '13 at 06:10
Can't I put those values into some property object in my bean class and use it in any class whenever I need it ? — antony.ouseph.k, Nov 14 '13 at 06:11
@antony.ouseph.k its already in url property of your bean. You can use the getter method on that bean to get url anywhere — Subin Sebastian, Nov 14 '13 at 06:16
How are you creating the bean object? is it created from Spring ApplicationContext or are you creating it using 'new' — Subin Sebastian, Nov 14 '13 at 06:26
+1 for that question. I am using new. but when I use applicationContext I have to mention the Spring.xml which I already mentioned in my web.xml. this confuses me. — antony.ouseph.k, Nov 14 '13 at 06:31
ApplicationContext context = new ClassPathXmlApplicationContext("Spring.xml"); DataBeanClass oBeanClass = (DataBeanClass) context.getBean("dataSource"); ----- here I have to mention the Spring.xml which I already mentioned in my web.xml. I was wondering is there anyother way to use applicationcontext ? — antony.ouseph.k, Nov 14 '13 at 06:34
http://stackoverflow.com/questions/11815339/role-purpose-of-contextloaderlistener-in-spring — Subin Sebastian, Nov 14 '13 at 06:48
read the above discussion to understand real purpose of contextLoaderListener — Subin Sebastian, Nov 14 '13 at 06:48
You can always use `context = ContextLoader.getCurrentWebApplicationContext();` as well to load the same context created during the initilization of container. — Subin Sebastian, Nov 14 '13 at 06:52

score 12 · Accepted Answer · answered Nov 14 '13 at 06:11

12

You can annotate your bean property like this, then spring will auto inject the property from your property file.

@Value("${url}")
private String url;

You dont have to extend PropertyPlaceholderConfigurer

Defining your bean like this will auto populate url as well, but annotation seems to be easiest way

<bean id="dataSource" class="org.tempuri.DataBeanClass">
   <property name="url" value="${url}"></property>
</bean>

answered Nov 14 '13 at 06:11

Subin Sebastian

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If I were to extend PropertyPlaceHolderConfigurer how should I do it ? – antony.ouseph.k Nov 14 '13 at 08:20

score 3 · Answer 2 · answered Nov 14 '13 at 09:31

Please do the following process to get property file value in class.

Define the bean for property file in your spring.xml
<util:properties id="dataProperties" location="classpath:/data.properties"/>
keep your data.properties under src/main/resources.
Use the following code to get value from property file for e.g to get value of url key in data.properties

private @Value("#{dataProperties['url']})
String url;

score 0 · Answer 3 · answered Nov 14 '13 at 06:18

Properties files can be made accessible to Spring via the following namespace element in Spring.xml

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

And then you can use like

@Autowired
private Environment env;
...
String url=env.getProperty("url"));

Note:

using <property-placeholder> will not expose the properties to the Spring Environment – this means that retrieving the value like this will not work – it will return null

but what is the point if env.getProperty("url")) does not work? — user1745356, Nov 11 '14 at 14:13

How to get the property value inside a spring bean class in my class ?

3 Answers3