Create E20250707 Spring application properties.md

Author: ecsimsw

backend/E20250707 Spring application properties.md

@@ -0,0 +1,15 @@
+``` java
+public static void main(String[] args) {
+    var app = new SpringApplication(DeviceApplication.class);
+    var ctx = app.run(args);
+    printActiveProperties(ctx.getEnvironment());
+}
+
+private static void printActiveProperties(ConfigurableEnvironment env) {
+    System.out.println("************************* ACTIVE APP PROPERTIES ******************************");
+    env.getPropertySources().stream().filter(ps -> ps instanceof OriginTrackedMapPropertySource)
+        .map(ps -> ((OriginTrackedMapPropertySource) ps).getSource().entrySet())
+        .flatMap(it -> it.stream())
+        .forEach(property -> System.out.println(property.getKey() + "=" + property.getValue()));
+}
+```