Moving derived data accessors out of the @Entity... have created a Bot @Service... and implemented the calls there but I'm unconvinced by this as not sure how we can then use that in the Controller/Model side of the code now. What I want to do is access a Bot's "id" which is derived from its username so needs code to build it. I'm starting to wonder if I should just store some of the derived data in the database but that feels clunky (could be more performant though, hmm..)

Java/Spring/activitypubbot/src/main/java/dev/activitypub/activitypubbot/APProperties.java

@@ -21,5 +21,4 @@ public class APProperties {
      * Server domain - i.e. https://<domain>/@username
      */
     @Getter @Setter private String domain; // = "activitypub.bot";
-
 }

Java/Spring/activitypubbot/src/main/java/dev/activitypub/activitypubbot/Bot.java

@@ -58,7 +58,6 @@ public class Bot {
     @Column(nullable=true,unique=false)
     @Getter @Setter private String summary; // "<p>A bot written using Java/Spring</p>",
 
-
     ///////////////////////////////////////////////////////////////////////////
     // The following values will be auto-generated on bot-creation
 
@@ -81,26 +80,8 @@ public class Bot {
     @Column(nullable=false,unique=false)
     @Getter private static final boolean indexable = false;
 
-    // TODO: should this class have the functions for generating derived values based on config vals? How does it get the config...
-    
-    /* these are all just derived from (preferred)Username - the scheme and domain-name should come from config
-    private String id; // "https://springbot.seth.id.au/users/springbot",
-    private String url; // "https://springbot.seth.id.au/@springbot",
-    private String inbox; // "https://springbot.seth.id.au/users/springbot/inbox",
-    private String publicKeyId; // "https://springbot.seth.id.au/users/springbot#main-key",
-    */
-    public String getId() {
-        // TODO: is there some sort of 'uribuilder' - probably need our own, lots of uris to build
-		//return props.getScheme() + "://" + props.getDomain() + "/users/" + this.getUsername();
-		return this.getUsername();
-    }
-
-    /* this is just a copy of "id"
-    private String publicKeyOwner; // "https://springap.seth.id.au/users/springbot",
-    */
-
     @Override
     public String toString() {
-        return "Bot: " + username;
+        return "Bot: " + this.username;
     }
 }

Java/Spring/activitypubbot/src/main/java/dev/activitypub/activitypubbot/BotController.java

@@ -20,11 +20,18 @@ public class BotController {
     @Autowired
     private BotRepo botRepo;
 
+    private BotService botService;
+
+    @Autowired
+    public BotController(BotService botService) {
+        this.botService = botService;
+    }
+
     @GetMapping("/viewbot")
     public String listAll(Model model) {
         log.info("WebHandler::viewbot");
 
-        List<Bot> botlist = botRepo.findAll();
+        List<Bot> botlist = botService.findAll();
         model.addAttribute("bots", botlist);
 
         return "viewbot";

Java/Spring/activitypubbot/src/main/java/dev/activitypub/activitypubbot/BotService.java

@@ -0,0 +1,65 @@
+package dev.activitypub.activitypubbot;
+
+import org.springframework.beans.BeanUtils;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+import java.util.List;
+
+/**
+ * The "business logic" and derived data of a Bot.
+ */
+@Service
+public class BotService {
+
+    @Autowired
+    private BotRepo repo;
+
+    @Autowired
+    private APProperties props;
+
+    @Transactional
+    public Bot create(Bot bot) {
+        // A user must have a key, so we generate and associate one on creation
+        // https://docs.joinmastodon.org/spec/activitypub/#publicKey
+        return repo.save(bot);
+    }
+
+    public List<Bot> findAll() {
+        return repo.findAll();
+    }
+
+
+    // whilst the URI structure of the below are up to the implementor we're using Mastodon as a reference
+
+    // TODO: perhaps these could just be templated elsewhere... or part of a separat JSON generator
+
+    /**
+     * Generate the users URI
+     */
+    private String getUsersURI() {
+        return props.getScheme() + "://" + props.getDomain() + "/users/";
+    }
+
+    /**
+     * The"id" of a bot (user/actor) is a URI combining domain and username: https://<domain>/users/<username>
+     */
+    public String getId(Bot bot) {
+        return getUsersURI() + bot.getUsername();
+    }
+
+    /**
+     * The "inbox" of a user is a URI of the form: https://<domain>/users/<username>/inbox
+     */
+    public String getInbox(Bot bot) {
+        return getUsersURI() + bot.getUsername() + "/inbox";
+    }
+
+    /**
+     * The "outbox" of a user is a URI of the form: https://<domain>/users/<username>/outbox
+     */
+    public String getOutbox(Bot bot) {
+        return getUsersURI() + bot.getUsername() + "/outbox";
+    }
+}
+