Invalid StartTransaction causes Transactions Page to Error

[brandonprry]

Checklist

• [x] I checked other issues already, but found no answer/solution
• [x] I checked the documentation and wiki, but found no answer/solution
• [x] I am running the latest version and the issue still occurs
• [x] I am sure that this issue is about SteVe (and not about the charging station software or something unrelated to SteVe)

Specifications

SteVe Version     : Version:	3.8.0-SNAPSHOT
Operating system  : Docker/OSX
JDK               : Docker/OSX
Database          : MariaDB

Expected Behavior

Page doesn't crash.

Actual Behavior

Page crashes.

Steps to Reproduce the Problem

1. Create a ChargePoint with an ID of 1
2. Send the following StartTransaction OCPP message

echo '[2, "dddb2599-d678-4ff8-bf38-a230390a1200", "StartTransaction", {"connectorId": 42, "meterStart": 42, "idTag": "some id", "timestamp": "222222017-10-27T19:10:11Z"}]'|websocat -H="Sec-WebSocket-Protocol:ocpp1.6" ws://localhost:8180/steve/websocket/CentralSystemService/1

This is the response I got back, which seems fine.

[3,"dddb2599-d678-4ff8-bf38-a230390a1200",{"transactionId":1,"idTagInfo":{"status":"Invalid"}}]

3. Check the Transactions page, it should have a stack trace.

Additional context

Thanks.

[juherr]

The issue comes first from the station which sent an invalid message.

Steve could reject the invalid message but it is possible the station will continue the send it.

Maybe Steve should drop the invalid message and notify about the issue.