Load mail.properties from resources (#118)

* Load mail.properties as resource

* Add JDs

Author: sven1103

subscription-provider/src/main/java/life/qbic/logging/subscription/provider/mail/property/MailPropertyLoader.java

@@ -4,6 +4,7 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.io.InputStream;
 import java.util.Properties;
 
 /**
@@ -22,9 +23,9 @@ public static MailPropertyLoader create() {
   }
 
   public Properties load() throws IOException {
-    String file = requireNonNull(getClass().getClassLoader().getResource(PROPERTIES),
-        "Cannot find property file. Please make sure to provide a file 'mail.properties' in the resources").getFile();
-    return PropertyFileParser.parse(new File(file));
+    InputStream stream = requireNonNull(getClass().getClassLoader().getResourceAsStream(PROPERTIES),
+        "Cannot find property file. Please make sure to provide a file 'mail.properties' in the resources");
+    return PropertyFileParser.parse(stream);
   }
 
 }

subscription-provider/src/main/java/life/qbic/logging/subscription/provider/mail/property/PropertyFileParser.java

@@ -6,6 +6,7 @@
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.IOException;
+import java.io.InputStream;
 import java.util.Properties;
 
 /**
@@ -52,6 +53,25 @@ public static Properties parse(File file) throws IOException {
     return properties;
   }
 
+  /**
+   * Parses an input stream for defined properties and resolves present placeholder against visible
+   * environment variables.
+   * @param inputStream the input stream with the defined properties
+   * @return a {@link Properties} object with the parsed properties
+   * @throws IOException if the file cannot be accessed
+   * @since 1.0.0
+   */
+  public static Properties parse(InputStream inputStream) throws IOException {
+    requireNonNull(inputStream, "Input stream must not be null");
+
+    var properties = new Properties();
+    properties.load(inputStream);
+
+    properties = resolvePlaceholders(properties);
+
+    return properties;
+  }
+
   private static Properties resolvePlaceholders(Properties properties) {
     var resolvedProperties = new Properties();
     properties.forEach((property, value) -> {