2 files changed, 8 insertions, 5 deletions
diff --git a/src/org/traccar/api/BaseResource.java b/src/org/traccar/api/BaseResource.java
index 368df7166..aa1101f02 100644
--- a/src/org/traccar/api/BaseResource.java
+++ b/src/org/traccar/api/BaseResource.java
@@ -22,12 +22,12 @@ public class BaseResource {
     @javax.ws.rs.core.Context
     private SecurityContext securityContext;
 
-    protected SecurityContext getSecurityContext() {
-        return securityContext;
-    }
-
     protected long getUserId() {
-        return ((UserPrincipal) securityContext.getUserPrincipal()).getUserId();
+        UserPrincipal principal = (UserPrincipal) securityContext.getUserPrincipal();
+        if (principal != null) {
+            return principal.getUserId();
+        }
+        return 0;
     }
 
 }
diff --git a/src/org/traccar/model/Command.java b/src/org/traccar/model/Command.java
index df62164c2..bc99967b6 100644
--- a/src/org/traccar/model/Command.java
+++ b/src/org/traccar/model/Command.java
@@ -15,6 +15,9 @@
  */
 package org.traccar.model;
 
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+
+@JsonIgnoreProperties(ignoreUnknown=true)
 public class Command extends Extensible {
 
     public static final String TYPE_POSITION_SINGLE = "positionSingle";