BAEL-2926 Guide to @EnableConfigurationProperties (#7186)

spring-boot/src/main/java/org/baeldung/properties/AdditionalConfiguration.java

@@ -0,0 +1,14 @@
+package org.baeldung.properties;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+@EnableConfigurationProperties(AdditionalProperties.class)
+public class AdditionalConfiguration {
+
+    @Autowired
+    private AdditionalProperties additionalProperties;
+
+}

spring-boot/src/main/java/org/baeldung/properties/AdditionalProperties.java

@@ -0,0 +1,26 @@
+package org.baeldung.properties;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+@ConfigurationProperties(prefix = "additional")
+public class AdditionalProperties {
+
+    private String unit;
+    private int max;
+
+    public String getUnit() {
+        return unit;
+    }
+
+    public void setUnit(String unit) {
+        this.unit = unit;
+    }
+
+    public int getMax() {
+        return max;
+    }
+
+    public void setMax(int max) {
+        this.max = max;
+    }
+}

spring-boot/src/main/java/org/baeldung/properties/ConfigPropertiesDemoApplication.java

@@ -5,11 +5,14 @@ import org.springframework.boot.builder.SpringApplicationBuilder;
 import org.springframework.context.annotation.ComponentScan;
 
 @SpringBootApplication
-@ComponentScan(basePackageClasses = { ConfigProperties.class, JsonProperties.class, CustomJsonProperties.class })
+@ComponentScan(basePackageClasses = {ConfigProperties.class,
+        JsonProperties.class,
+        CustomJsonProperties.class,
+        AdditionalConfiguration.class})
 public class ConfigPropertiesDemoApplication {
     public static void main(String[] args) {
         new SpringApplicationBuilder(ConfigPropertiesDemoApplication.class).initializers(new JsonPropertyContextInitializer())
-            .run();
+                .run();
     }
 
 }

spring-boot/src/test/java/com/baeldung/properties/ConfigPropertiesIntegrationTest.java

@@ -1,5 +1,6 @@
 package com.baeldung.properties;
 
+import org.baeldung.properties.AdditionalProperties;
 import org.baeldung.properties.ConfigProperties;
 import org.baeldung.properties.ConfigPropertiesDemoApplication;
 import org.junit.Assert;
@@ -18,6 +19,9 @@ public class ConfigPropertiesIntegrationTest {
     @Autowired
     private ConfigProperties properties;
 
+    @Autowired
+    private AdditionalProperties additionalProperties;
+
     @Test
     public void whenSimplePropertyQueriedthenReturnsProperty() throws Exception {
         Assert.assertTrue("From address is read as null!", properties.getFrom() != null);
@@ -42,4 +46,10 @@ public class ConfigPropertiesIntegrationTest {
         Assert.assertTrue("Incorrectly bound object property!", properties.getCredentials().getUsername().equals("john"));
         Assert.assertTrue("Incorrectly bound object property!", properties.getCredentials().getPassword().equals("password"));
     }
+
+    @Test
+    public void whenAdditionalPropertyQueriedthenReturnsProperty() {
+        Assert.assertTrue(additionalProperties.getUnit().equals("km"));
+        Assert.assertTrue(additionalProperties.getMax() == 100);
+    }
 }

spring-boot/src/test/resources/configprops-test.properties

@@ -20,3 +20,7 @@ mail.credentials.authMethod=SHA1
 #Bean method properties
 item.name=Test item name
 item.size=21
+
+#Additional properties
+additional.unit=km
+additional.max=100