Senden von bereits verschlüsselten Anträgen inkl. Abruf von PK

• introduce strategies for sending normal submissions and submissions where data is already encrypted
• move logic out of client builder
• change order of fluent calls to cover common cases (destinationId, serviceType) between the strategies as last steps

api/src/main/java/de/fitko/fitconnect/api/config/ApplicationConfig.java

 package de.fitko.fitconnect.api.config;
 
+import de.fitko.fitconnect.api.exceptions.InitializationException;
 import lombok.AllArgsConstructor;
 import lombok.Builder;
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
 import java.util.Map;
+import java.util.stream.Collectors;
 
 @Data
 @Builder
@@ -15,23 +17,35 @@ public class ApplicationConfig {
 
     @Builder.Default
     private String httpProxyHost = "";
+
     @Builder.Default
     private Integer httpProxyPort = 0;
+
     @Builder.Default
     private Integer requestTimeoutInSeconds = 30;
-    private String metadataSchemaPath;
-    private String privateSigningKeyPath;
+
+    @Builder.Default
+    private String metadataSchemaPath = "";
+
+    @Builder.Default
+    private String privateSigningKeyPath = "";
 
     private SenderConfig senderConfig;
+
     private SubscriberConfig subscriberConfig;
 
     private Map<EnvironmentName, Environment> environments;
+
     private EnvironmentName activeEnvironment;
 
     private ResourcePaths resourcePaths;
 
     public Environment getEnvironmentByName(final EnvironmentName environmentName) {
-        return environments.get(environmentName);
+        if (environments.containsKey(environmentName)) {
+            return environments.get(environmentName);
+        } else {
+            throw new InitializationException("No environment with name '" + environmentName.getName() + "' found. Available environments are: " + getAvailableEnvironmentNames());
+        }
     }
 
     public Environment getCurrentEnvironment() {
@@ -69,5 +83,12 @@ public class ApplicationConfig {
     private String getSubmissionBaseUrl() {
         return getCurrentEnvironment().getSubmissionBaseUrl();
     }
+
+    private String getAvailableEnvironmentNames() {
+        return environments.keySet()
+                .stream()
+                .map(EnvironmentName::getName)
+                .collect(Collectors.joining(" | "));
+    }
 }