eugenp · saajn · Aug 27, 2024 · Aug 17, 2024
diff --git a/spring-boot-modules/spring-boot-3-3/pom.xml b/spring-boot-modules/spring-boot-3-3/pom.xml
@@ -41,6 +41,25 @@
             <artifactId>langchain4j-ollama</artifactId>
             <version>${langchain4j.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-starter</artifactId>
+            <version>${spring-cloud-starter.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-starter-config</artifactId>
+            <version>${spring-cloud-starter.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-actuator</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.awaitility</groupId>
+            <artifactId>awaitility</artifactId>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
     <build>
         <plugins>
@@ -65,5 +84,6 @@
         <spring-boot.version>3.2.4</spring-boot.version>
         <apache-camel.version>4.7.0</apache-camel.version>
         <langchain4j.version>0.33.0</langchain4j.version>
+        <spring-cloud-starter.version>4.1.3</spring-cloud-starter.version>
     </properties>
 </project>
diff --git a/...main/java/com/baeldung/dynamically/updating/properties/UpdatingPropertiesApplication.java b/...main/java/com/baeldung/dynamically/updating/properties/UpdatingPropertiesApplication.java
@@ -0,0 +1,13 @@
+package com.baeldung.dynamically.updating.properties;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class UpdatingPropertiesApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(UpdatingPropertiesApplication.class, args);
+    }
+
+}
diff --git a/...ain/java/com/baeldung/dynamically/updating/properties/controllers/PropertyController.java b/...ain/java/com/baeldung/dynamically/updating/properties/controllers/PropertyController.java
@@ -0,0 +1,29 @@
+package com.baeldung.dynamically.updating.properties.controllers;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.*;
+
+import com.baeldung.dynamically.updating.properties.services.ExampleBean;
+import com.baeldung.dynamically.updating.properties.services.PropertyUpdaterService;
+
+@RestController
+@RequestMapping("/properties")
+public class PropertyController {
+
+    @Autowired
+    private PropertyUpdaterService propertyUpdaterService;
+
+    @Autowired
+    private ExampleBean exampleBean;
+
+    @PostMapping("/update")
+    public String updateProperty(@RequestParam String key, @RequestParam String value) {
+        propertyUpdaterService.updateProperty(key, value);
+        return "Property updated. Remember to call the actuator /actuator/refresh";
+    }
+
+    @GetMapping("/customProperty")
+    public String getCustomProperty() {
+        return exampleBean.getCustomProperty();
+    }
+}
diff --git a/...-3-3/src/main/java/com/baeldung/dynamically/updating/properties/services/ExampleBean.java b/...-3-3/src/main/java/com/baeldung/dynamically/updating/properties/services/ExampleBean.java
@@ -0,0 +1,17 @@
+package com.baeldung.dynamically.updating.properties.services;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.cloud.context.config.annotation.RefreshScope;
+import org.springframework.stereotype.Component;
+
+@RefreshScope
+@Component
+public class ExampleBean {
+
+    @Value("${my.custom.property}")
+    private String customProperty;
+
+    public String getCustomProperty() {
+        return customProperty;
+    }
+}
diff --git a/...in/java/com/baeldung/dynamically/updating/properties/services/PropertyUpdaterService.java b/...in/java/com/baeldung/dynamically/updating/properties/services/PropertyUpdaterService.java
@@ -0,0 +1,31 @@
+package com.baeldung.dynamically.updating.properties.services;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.core.env.ConfigurableEnvironment;
+import org.springframework.core.env.MapPropertySource;
+import org.springframework.core.env.MutablePropertySources;
+import org.springframework.stereotype.Service;
+
+@Service
+public class PropertyUpdaterService {
+
+    private static final String DYNAMIC_PROPERTIES_SOURCE_NAME = "dynamicProperties";
+
+    @Autowired
+    private ConfigurableEnvironment environment;
+
+    public void updateProperty(String key, String value) {
+        MutablePropertySources propertySources = environment.getPropertySources();
+        if (!propertySources.contains(DYNAMIC_PROPERTIES_SOURCE_NAME)) {
+            Map<String, Object> dynamicProperties = new HashMap<>();
+            dynamicProperties.put(key, value);
+            propertySources.addFirst(new MapPropertySource(DYNAMIC_PROPERTIES_SOURCE_NAME, dynamicProperties));
+        } else {
+            MapPropertySource propertySource = (MapPropertySource) propertySources.get(DYNAMIC_PROPERTIES_SOURCE_NAME);
+            propertySource.getSource().put(key, value);
+        }
+    }
+}
diff --git a/...-3-3/src/main/java/com/baeldung/dynamically/updating/properties/utility/CustomConfig.java b/...-3-3/src/main/java/com/baeldung/dynamically/updating/properties/utility/CustomConfig.java
@@ -0,0 +1,16 @@
+package com.baeldung.dynamically.updating.properties.utility;
+
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Scope;
+
+@Configuration
+public class CustomConfig {
+
+    @Bean
+    @Scope("prototype")
+    public MyService myService(@Value("${custom.property:default}") String property) {
+        return new MyService(property);
+    }
+}
diff --git a/...oot-3-3/src/main/java/com/baeldung/dynamically/updating/properties/utility/MyService.java b/...oot-3-3/src/main/java/com/baeldung/dynamically/updating/properties/utility/MyService.java
@@ -0,0 +1,14 @@
+package com.baeldung.dynamically.updating.properties.utility;
+
+public class MyService {
+
+    private final String property;
+
+    public MyService(String property) {
+        this.property = property;
+    }
+
+    public String getProperty() {
+        return property;
+    }
+}
diff --git a/spring-boot-modules/spring-boot-3-3/src/main/resources/application.properties b/spring-boot-modules/spring-boot-3-3/src/main/resources/application.properties
@@ -12,3 +12,15 @@ ollama.max_response_length=1000
 # Logging configuration
 logging.level.root=INFO
 logging.level.com.baeldung.chatbot=DEBUG
+logging.level.com.baeldung.dynamically.updating.properties=DEBUG
+logging.level.org.springframework.boot.actuate=DEBUG
+
+# We can disable Spring Cloud Config to prevent the application from trying to connect to a configuration server
+spring.cloud.config.enabled=false
+# Enable the Spring Boot Actuator endpoints to trigger a refresh
+management.endpoint.refresh.enabled=true
+management.endpoints.web.exposure.include=refresh
+
+# Example property to be changed at runtime
+my.custom.property=defaultValue
+
diff --git a/...-3-3/src/test/java/com/baeldung/dynamically/updating/properties/CustomConfigUnitTest.java b/...-3-3/src/test/java/com/baeldung/dynamically/updating/properties/CustomConfigUnitTest.java
@@ -0,0 +1,34 @@
+package com.baeldung.dynamically.updating.properties;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.context.ApplicationContext;
+import org.springframework.test.context.junit.jupiter.SpringExtension;
+
+import com.baeldung.dynamically.updating.properties.utility.MyService;
+
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+@ExtendWith(SpringExtension.class)
+@SpringBootTest(classes = UpdatingPropertiesApplication.class)
+public class CustomConfigUnitTest {
+
+    @Autowired
+    private ApplicationContext context;
+
+    @Test
+    void whenPropertyInjected_thenServiceUsesCustomProperty() {
+        MyService service = context.getBean(MyService.class);
+        assertEquals("default", service.getProperty());
+    }
+
+    @Test
+    void whenPropertyChanged_thenServiceUsesUpdatedProperty() {
+        System.setProperty("custom.property", "updated");
+        MyService service = context.getBean(MyService.class);
+        assertEquals("updated", service.getProperty());
+    }
+}
diff --git a/...est/java/com/baeldung/dynamically/updating/properties/PropertyUpdaterServiceUnitTest.java b/...est/java/com/baeldung/dynamically/updating/properties/PropertyUpdaterServiceUnitTest.java
@@ -0,0 +1,48 @@
+package com.baeldung.dynamically.updating.properties;
+
+import static org.awaitility.Awaitility.await;
+
+import java.util.concurrent.TimeUnit;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.Timeout;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.web.server.LocalServerPort;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.web.client.RestTemplate;
+
+import com.baeldung.dynamically.updating.properties.services.ExampleBean;
+import com.baeldung.dynamically.updating.properties.services.PropertyUpdaterService;
+
+@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
+public class PropertyUpdaterServiceUnitTest {
+
+    @Autowired
+    private PropertyUpdaterService propertyUpdaterService;
+
+    @Autowired
+    private ExampleBean exampleBean;
+
+    @LocalServerPort
+    private int port;
+
+    @Test
+    @Timeout(5)
+    public void whenUpdatingProperty_thenPropertyIsUpdatedAndRefreshed() throws InterruptedException {
+        // Injects a new property into the test context
+        propertyUpdaterService.updateProperty("my.custom.property", "newValue");
+
+        // Trigger the refresh by calling the actuator endpoint
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.APPLICATION_JSON);
+        HttpEntity<String> entity = new HttpEntity<>(null, headers);
+        RestTemplate restTemplate = new RestTemplate();
+        restTemplate.postForEntity("http://localhost:" + port + "/actuator/refresh", entity, String.class);
+
+        // Awaitility to wait until the property is updated
+        await().atMost(5, TimeUnit.SECONDS).until(() -> "newValue".equals(exampleBean.getCustomProperty()));
+    }
+}