ZetCode

Spring @PropertySource annotation tutorial

last modified October 18, 2023

Spring @PropertySource annotation tutorial shows how to use @PropertySource annotation to include properties into the Environment and inject properties with @Value.

Spring is a popular Java application framework for creating enterprise applications.

Spring @PropertySource

@PropertySource is a convenient annotation for including PropertySource to Spring's Environment and allowing to inject properties via @Value into class attributes. (PropertySource is an object representing a set of property pairs from a particular source.)

@PropertySource is used together with @Configuration.

Spring @PropertySource example

The application uses Spring's @PropertySource to include properties from the application.properties file into the Environment and to inject them into class attributes.

pom.xml
src
├───main
│ ├───java
│ │ └───com
│ │ └───zetcode
│ │ │ Application.java
│ │ └───config
│ │ AppConfig.java
│ └───resources
│ application.properties
│ logback.xml
└───test
 └───java

This is the project structure.

pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 <modelVersion>4.0.0</modelVersion>
 <groupId>com.zetcode</groupId>
 <artifactId>propertysource</artifactId>
 <version>1.0-SNAPSHOT</version>
 <properties>
 <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 <maven.compiler.source>17</maven.compiler.source>
 <maven.compiler.target>17</maven.compiler.target>
 <spring-version>5.3.23</spring-version>
 </properties>
 <dependencies>
 <dependency>
 <groupId>ch.qos.logback</groupId>
 <artifactId>logback-classic</artifactId>
 <version>1.4.0</version>
 </dependency>
 <dependency>
 <groupId>org.springframework</groupId>
 <artifactId>spring-context</artifactId>
 <version>${spring-version}</version>
 </dependency>
 <dependency>
 <groupId>org.springframework</groupId>
 <artifactId>spring-core</artifactId>
 <version>${spring-version}</version>
 </dependency> 
 
 </dependencies>
 <build>
 <plugins>
 <plugin>
 <groupId>org.codehaus.mojo</groupId>
 <artifactId>exec-maven-plugin</artifactId>
 <version>3.1.0</version>
 <configuration>
 <mainClass>com.zetcode.Application</mainClass>
 </configuration>
 </plugin>
 </plugins>
 </build>
</project>

In the pom.xml file, we have basic Spring dependencies spring-core, spring-context, and logging logback-classic dependency.

The exec-maven-plugin is used for executing Spring application from the Maven on the command line.

resources/logback.xml
<?xml version="1.0" encoding="UTF-8"?>
<configuration>
 <logger name="org.springframework" level="ERROR"/>
 <logger name="com.zetcode" level="INFO"/>
 <appender name="consoleAppender" class="ch.qos.logback.core.ConsoleAppender">
 <encoder>
 <Pattern>%d{HH:mm:ss.SSS} %blue(%-5level) %magenta(%logger{36}) - %msg %n
 </Pattern>
 </encoder>
 </appender>
 <root>
 <level value="INFO" />
 <appender-ref ref="consoleAppender" />
 </root>
</configuration>

The logback.xml is a configuration file for the Logback logging library.

resources/application.properties
app.name=My application
app.version=1.1

We have two properties in application.properties file.

com/zetcode/config/AppConfig.java
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 {
}

AppConfig is the application configuration class. The @PropertySource injects properties from the application.properties into the Spring's Environment.

com/zetcode/Application.java
package com.zetcode;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.core.env.Environment;
@ComponentScan(basePackages = "com.zetcode")
public class Application {
 private static final Logger logger = LoggerFactory.getLogger(Application.class);
 @Autowired
 private Environment env;
 @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();
 }
 private void run() {
 logger.info("From Environment");
 logger.info("Application name: {}", env.getProperty("app.name"));
 logger.info("Application version: {}", env.getProperty("app.version"));
 logger.info("Using @Value injection");
 logger.info("Application name: {}", appName);
 logger.info("Application version: {}", appVersion);
 }
}

In the Application, we get the properties using two methods.

@Autowired
private Environment env;

We inject the Environment. We can retrieve the properties with its getProperty method.

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

We inject the properties with @Value annotation into the attributes.

logger.info("From Environment");
logger.info("Application name: {}", env.getProperty("app.name"));
logger.info("Application version: {}", env.getProperty("app.version"));

The first way to retrieve properties is from the Environment using the getProperty method.

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

The second way is to use the injected attributes.

$ mvn -q exec:java
15:00:20.653 INFO com.zetcode.Application - From Environment 
15:00:20.668 INFO com.zetcode.Application - Application name: My application 
15:00:20.668 INFO com.zetcode.Application - Application version: 1.1 
15:00:20.668 INFO com.zetcode.Application - Using @Value injection 
15:00:20.668 INFO com.zetcode.Application - Application name: My application 
15:00:20.668 INFO com.zetcode.Application - Application version: 1.1 

We run the application.

In this article we have shown how to use @PropertySource annotation to conveniently work with properties in a Spring application.

Author

My name is Jan Bodnar, and I am a passionate programmer with extensive programming experience. I have been writing programming articles since 2007. To date, I have authored over 1,400 articles and 8 e-books. I possess more than ten years of experience in teaching programming.

List all Spring tutorials.

AltStyle によって変換されたページ (->オリジナル) /