BAEL-6229: loading multiple yaml files in spring boot (#13724)

* BAEL-6229: committing new example for loading multiple yaml configuration files

* BAEL-6229: updating README.md

* BAEL-6229: adding example one code, commented out

* Revert "BAEL-6229: updating README.md"

This reverts commit 51cd2dcf97f797aa6a723888fd246ef0142242a3.

* BAEL-6229: adding comments around commented out code for first example.

spring-boot-modules/spring-boot-properties-3/src/main/java/com/baeldung/properties/multipleyaml/MultipleYamlApplication.java

@@ -0,0 +1,27 @@
+package com.baeldung.properties.multipleyaml;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class MultipleYamlApplication implements CommandLineRunner {
+
+    @Autowired
+    private MultipleYamlConfiguration config;
+
+    public static void main(String[] args) {
+        SpringApplication springApp = new SpringApplication(MultipleYamlApplication.class);
+
+        // Code from first example, uncomment to use multiple profiles
+        // springApp.setAdditionalProfiles("students", "teachers");
+
+        springApp.run(args);
+    }
+
+    public void run(String... args) throws Exception {
+        System.out.println("Students: " + config.getStudents());
+        System.out.println("Teachers: " + config.getTeachers());
+    }
+}

spring-boot-modules/spring-boot-properties-3/src/main/java/com/baeldung/properties/multipleyaml/MultipleYamlConfiguration.java

@@ -0,0 +1,35 @@
+package com.baeldung.properties.multipleyaml;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.context.annotation.PropertySources;
+
+import java.util.List;
+
+@Configuration
+@ConfigurationProperties
+@PropertySources({
+        @PropertySource(value = "classpath:application-teachers.yml", factory = MultipleYamlPropertySourceFactory.class),
+        @PropertySource(value = "classpath:application-students.yml", factory = MultipleYamlPropertySourceFactory.class)})
+public class MultipleYamlConfiguration {
+
+    List<String> teachers;
+    List<String> students;
+
+    public void setTeachers(List<String> teachers) {
+        this.teachers = teachers;
+    }
+
+    public void setStudents(List<String> students) {
+        this.students = students;
+    }
+
+    public List<String> getTeachers() {
+        return teachers;
+    }
+
+    public List<String> getStudents() {
+        return students;
+    }
+}

spring-boot-modules/spring-boot-properties-3/src/main/java/com/baeldung/properties/multipleyaml/MultipleYamlPropertySourceFactory.java

@@ -0,0 +1,23 @@
+package com.baeldung.properties.multipleyaml;
+
+import org.springframework.beans.factory.config.YamlPropertiesFactoryBean;
+import org.springframework.core.env.PropertiesPropertySource;
+import org.springframework.core.env.PropertySource;
+import org.springframework.core.io.support.EncodedResource;
+import org.springframework.core.io.support.PropertySourceFactory;
+
+import java.io.IOException;
+import java.util.Properties;
+
+public class MultipleYamlPropertySourceFactory implements PropertySourceFactory {
+
+    @Override
+    public PropertySource<?> createPropertySource(String name, EncodedResource encodedResource) throws IOException {
+        YamlPropertiesFactoryBean factory = new YamlPropertiesFactoryBean();
+        factory.setResources(encodedResource.getResource());
+
+        Properties properties = factory.getObject();
+
+        return new PropertiesPropertySource(encodedResource.getResource().getFilename(), properties);
+    }
+}

spring-boot-modules/spring-boot-properties-3/src/main/resources/application-students.yml

@@ -0,0 +1,3 @@
+students:
+  - Jane
+  - Michael

spring-boot-modules/spring-boot-properties-3/src/main/resources/application-teachers.yml

@@ -0,0 +1,3 @@
+teachers:
+  - Margo
+  - Javier

spring-boot-modules/spring-boot-properties-3/src/main/resources/application.yml

@@ -2,6 +2,10 @@ bael:
   root-level-property: defaultRootLevelValue
 spring:
   profiles:
+# Multiple profiles for MultipleYamlApplication first example
+#    include:
+#      - teachers
+#      - students
     group:
       multidocument-integration: multidocument-integration-extension
 ---