Added a key/value context store to PrincipalExtended

FROST-Server.Util/src/main/java/de/fraunhofer/iosb/ilt/frostserver/util/user/PrincipalExtended.java

@@ -19,6 +19,8 @@
 
 import java.security.Principal;
 import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Set;
 
 /**
@@ -40,6 +42,7 @@ public class PrincipalExtended implements Principal {
     private final String name;
     private final boolean admin;
     private final Set<String> roles;
+    private Map<String, Object> context;
 
     public PrincipalExtended(String name, boolean admin, Set<String> roles) {
         this.name = name;
@@ -65,6 +68,84 @@ public String toString() {
         return name + " (" + admin + ")";
     }
 
+    /**
+     * Get the current context map.
+     *
+     * @return the current context map.
+     */
+    public Map<String, Object> getContext() {
+        return context;
+    }
+
+    /**
+     * Add an item to the context, or replace an existing item if an item with
+     * the given key already exists.
+     *
+     * @param key The key to store the item under.
+     * @param value The value to associate with the given key.
+     * @return this.
+     */
+    public PrincipalExtended addContextItem(String key, Object value) {
+        if (context == null) {
+            context = new HashMap<>();
+        }
+        context.put(key, value);
+        return this;
+    }
+
+    /**
+     * Check if the context has an item for the given key.
+     *
+     * @param key the key to check.
+     * @return true if there is a context item for the given key, false
+     * otherwise.
+     */
+    public boolean hasContextItem(String key) {
+        if (context == null) {
+            return false;
+        }
+        return context.containsKey(key);
+    }
+
+    /**
+     * Get the context item with the given key, or dflt if there is no such
+     * item.
+     *
+     * @param key The key to get the item for.
+     * @param dflt The value to return if there is no value for the given key.
+     * @return The value for the given key, or dflt if there is no such item.
+     */
+    public Object getContextItem(String key, Object dflt) {
+        if (context == null) {
+            return dflt;
+        }
+        Object value = context.get(key);
+        if (value == null) {
+            return dflt;
+        }
+        return value;
+    }
+
+    /**
+     * Get the context item with the given key, or null if there is no such
+     * item.
+     *
+     * @param key The key to get the item for.
+     * @return The value for the given key, or null if there is no such item.
+     */
+    public Object getContextItem(String key) {
+        return getContextItem(key, null);
+    }
+
+    /**
+     * Replace the current context with the given value.
+     *
+     * @param context The context map to replace the current context with.
+     */
+    public void setContext(Map<String, Object> context) {
+        this.context = context;
+    }
+
     /**
      * Turns the given principal into a PrincipalExtended. A null value will
      * turn into an anonymous principal extended.