diff --git a/audience-retriever/src/main/java/net/ihe/gazelle/app/audienceretriever/adapter/AudienceSecretRetrieverForSoapui.java b/audience-retriever/src/main/java/net/ihe/gazelle/app/audienceretriever/adapter/AudienceSecretRetrieverForSoapui.java
index 3570a14490cb3869f1ca08c0bd510fe49e5aa249..3252c5bb42eee2abc72e64ea1f44b5bea73b7453 100644
--- a/audience-retriever/src/main/java/net/ihe/gazelle/app/audienceretriever/adapter/AudienceSecretRetrieverForSoapui.java
+++ b/audience-retriever/src/main/java/net/ihe/gazelle/app/audienceretriever/adapter/AudienceSecretRetrieverForSoapui.java
@@ -8,22 +8,40 @@ import java.io.FileInputStream;
 import java.io.IOException;
 import java.util.Properties;
 
+/**
+ * {@link AudienceSecretRetriever} used by SoapUI project to retrieve secrets.
+ */
 public class AudienceSecretRetrieverForSoapui implements AudienceSecretRetriever {
 
     private static final GazelleLogger LOGGER = GazelleLoggerFactory.getInstance().getLogger(AudienceSecretRetrieverForSoapui.class);
 
     private String propertiesFile = "/opt/simulators/audience.properties";
 
+    /**
+     * Default constructor for the class.
+     */
     public AudienceSecretRetrieverForSoapui() {
+        //Empty Constructor
     }
 
+    /**
+     * Constructor allowing to configure the properties file path.
+     *
+     * @param propertiesFile path to the properties file.
+     */
     public AudienceSecretRetrieverForSoapui(String propertiesFile) {
         this.propertiesFile = propertiesFile;
     }
 
-    public static Properties readPropertiesFile(String fileName) {
+    /**
+     * Read property file as {@link Properties}.
+     *
+     * @param filePath path to hte properties file.
+     * @return the {@link Properties} defined by the file.
+     */
+    private static Properties readPropertiesFile(String filePath) {
         Properties prop = null;
-        try (FileInputStream fis = new FileInputStream(fileName)) {
+        try (FileInputStream fis = new FileInputStream(filePath)) {
             prop = new Properties();
             prop.load(fis);
         } catch (IOException e) {
@@ -32,9 +50,12 @@ public class AudienceSecretRetrieverForSoapui implements AudienceSecretRetriever
         return prop;
     }
 
+    /**
+     * {@inheritDoc}
+     */
     @Override
     public String retrieveSecretForAudience(String audience) {
         Properties prop = readPropertiesFile(propertiesFile);
-        return prop.getProperty(audience);
+        return prop != null ? prop.getProperty(audience) : null;
     }
 }