@Value not resolved when using @PropertySource annotation. How to configure PropertySourcesPlaceholderConfigurer?

Question

I have following configuration class:

@Configuration
@PropertySource(name = \"props\", value = \"classpath:/app-config.properties\")
@ComponentScan(\"service         


        

Answer 1

I found the reason @value was not working for me is, @value requires PropertySourcesPlaceholderConfigurer instead of a PropertyPlaceholderConfigurer. I did the same changes and it worked for me, I am using spring 4.0.3 release. I configured this using below code in my configuration file.

@Bean
public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
   return new PropertySourcesPlaceholderConfigurer();
}

Answer 2

Since Spring 4.3 RC2 using PropertySourcesPlaceholderConfigurer or <context:property-placeholder> is not needed anymore. We can use directly @PropertySource with @Value. See this Spring framework ticket

I have created a test application with Spring 5.1.3.RELEASE. The application.properties contains two pairs:

app.name=My application
app.version=1.1

The AppConfig loads the properties via @PropertySource.

package com.zetcode.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;

@Configuration
@PropertySource(value = "application.properties", ignoreResourceNotFound = true)
public class AppConfig {

}

The Application injects the properties via @Value and uses them.

package com.zetcode;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;

@ComponentScan(basePackages = "com.zetcode")
public class Application {

    private static final Logger logger = LoggerFactory.getLogger(Application.class);

    @Value("${app.name}")
    private String appName;

    @Value("${app.version}")
    private String appVersion;

    public static void main(String[] args) {

        var ctx = new AnnotationConfigApplicationContext(Application.class);
        var app = ctx.getBean(Application.class);

        app.run();

        ctx.close();
    }

    public void run() {

        logger.info("Application name: {}", appName);
        logger.info("Application version: {}", appVersion);
    }
}

The output is:

$ mvn -q exec:java
22:20:10.894 [com.zetcode.Application.main()] INFO  com.zetcode.Application - Application name: My application
22:20:10.894 [com.zetcode.Application.main()] INFO  com.zetcode.Application - Application version: 1.1

Answer 3

In my case, depends-on="bean1" was within property-placeholder was causing the issue. I removed that dependency and used @PostConstruct to achieve the same original functionality and was able to read the new values too.

Answer 4

as @cwash said;

@Configuration
@PropertySource("classpath:/test-config.properties")
public class TestConfig {

     @Value("${name}")
     public String name;


     //You need this
     @Bean
     public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
        return new PropertySourcesPlaceholderConfigurer();
     }

}

Answer 5

The thing is: as far as I get it, <util:propertes id="id" location="loc"/>, is just a shorthand for

<bean id="id" class="org.springframework.beans.factory.config.PropertiesFactoryBean">
  <property name="location" value="loc"/>
</bean>

(see documentation of util:properties). Thus, when you use util:properties, a standalone bean is created.

@PropertySource, on the other hand, as documentation says is an

annotation providing a convenient and declarative mechanism for adding a PropertySource to Spring's Environment'.

(see @PropertySource doc). So it doesn't create any bean.

Then "#{a['something']}" is a SpEL expression (see SpEL), that means "get something from bean 'a'". When util:properties is used, the bean exists and the expression is meaningful, but when @PropertySource is used, there is no actual bean and the expression is meaningless.

You can workaround this either by using XML (which is the best way, I think) or by issuing a PropertiesFactoryBean by yourself, declaring it as a normal @Bean.

Answer 6

This can also be configured in java this way

@Bean
public static PropertySourcesPlaceholderConfigurer properties() {
    PropertySourcesPlaceholderConfigurer configurer = new PropertySourcesPlaceholderConfigurer();
    configurer.setIgnoreUnresolvablePlaceholders(true);
    configurer.setIgnoreResourceNotFound(true);
    return configurer;
}