java - Spring @Value annotation returns null

Question

I'm trying to take advantage of @Value annotation and auto-populate my string-variable from the properties file, but with no luck. Values are not being set and are null.

Here is my configuration:

SendMessageController.java

@RestController
public class SendMessageController {

    @Value("${client.keystore.type}")
    private static String keystoreType;

    @RequestMapping(value = "/sendMessage", method = RequestMethod.POST)
    public ResponseEntity<SendMessageResponse> sendMessage(@Validated @RequestBody SendMessageRequest messageRequest) {
    .......
    }

application.properties

client.keystore.type=JKS

rest-servlet.xml

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">


    <context:component-scan base-package="org.example.controllers" />

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

    <bean id="validator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean"/>
    <mvc:annotation-driven />

</beans>

When I run my application and try to access keystoreType variable it is always null. What am I doing wrong?

Can you please make sure the import statement for `@Value` annotation is `import org.springframework.beans.factory.annotation.Value;`? — Darshan Mehta, Apr 10 '16 at 18:52
Spring doesn't process `static` anything. Why is your field `static`? — Savior, Apr 10 '16 at 18:53
okay, after making the variable non-static, everything works fine. thanks. — Oleg, Apr 10 '16 at 18:57

score 16 · Accepted Answer · answered Apr 10 '16 at 18:55

16

Spring can not inject @Value to a static field directly.

you can either add inject the value through an annotated setter like this:

private static String keystoreType;

@Value("${client.keystore.type}")
public void setKeystoreType(String keystoreType) {
    SendMessageController.keystoreType = keystoreType;
}

Or Change :

    @Value("${client.keystore.type}")
    private static String keystoreType;

to :

@Value("${client.keystore.type}")
private String keystoreType;

answered Apr 10 '16 at 18:55

Rafik BELDI

4,140
4
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thank you for your explanation, this solved the problem – Oleg Apr 10 '16 at 19:00
sure! waiting for the timeout :) – Oleg Apr 10 '16 at 19:06
@RafikBELDI This thing is not working for me. I am calling the static method from other class , which has the static var . – Kamini Jul 28 '17 at 10:18

score 1 · Answer 2 · answered Jun 11 '20 at 11:44

1

For the ones still facing the issue after all the preceding suggestions, make sure you are not accessing that variable before the bean has been constructed as described in this answer.

answered Jun 11 '20 at 11:44

Philippe Simo

1,353
1
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28

java - Spring @Value annotation returns null

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