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Error: An exception occurred while logging debug-info - source: ContextUtil.splitKeyValueStringAndGroupByKey

See original GitHub issue

Hi Javalin team,

First of all thanks for this wonderful framework, I’ve been a big fan since the Spark times (https://sparkjava.com/) 🙂 ! Now I think I’ve found a bug in the debugger ^^. I’ve tried to minimize the number of potential error sources on my side, but there is maybe some chance left that its related to my HTTP calls. Here we go:

Actual behavior (the bug)

Data is sent to the server via HTTP POST (Content-Type=application/json) with a request body that is a JSON string containing the object: {"name": "Test %"}.
When request debugging is OFF everything works without problem!
When request debugging is ON (Javalin -> config.enableDevLogging()) the debugger crashes with the following exception:

[qtp1169794610-15] INFO io.javalin.Javalin - An exception occurred while logging debug-info
java.lang.IllegalArgumentException: URLDecoder: Illegal hex characters in escape (%) pattern - Error at index 0 in: ""}"
	at java.base/java.net.URLDecoder.decode(URLDecoder.java:232)
	at java.base/java.net.URLDecoder.decode(URLDecoder.java:142)
	at io.javalin.http.util.ContextUtil.splitKeyValueStringAndGroupByKey(ContextUtil.kt:37)
	at io.javalin.http.Context.formParamMap(Context.kt:186)
	at io.javalin.core.util.LogUtil.requestDevLogger(LogUtil.kt:35)
	at io.javalin.http.JavalinServlet.service(JavalinServlet.kt:83)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
	at io.javalin.websocket.JavalinWsServlet.service(JavalinWsServlet.kt:51)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
	at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:763)
	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:551)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
	at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1610)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
	at io.javalin.core.JavalinServer$start$wsAndHttpHandler$1.doHandle(JavalinServer.kt:49)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:489)
	at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1580)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1284)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
	at org.eclipse.jetty.server.handler.StatisticsHandler.handle(StatisticsHandler.java:173)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
	at org.eclipse.jetty.server.Server.handle(Server.java:501)
	at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:383)
	at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:556)
	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:375)
	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:272)
	at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
	at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:103)
	at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:336)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:313)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:171)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:129)
	at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:375)
	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:806)
	at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:938)
	at java.base/java.lang.Thread.run(Thread.java:834)

Expected behavior

The URLDecoder: Illegal hex characters in escape (%) pattern is not happening because the string is already decoded.

To Reproduce

Enable request debugging and send a simple JSON Object as described above.

Additional context

A successful request with {"name": "Test"} creates this log entry for me:

----------------------------------------------------------------------------------
[qtp1169794610-15] INFO io.javalin.Javalin - JAVALIN REQUEST DEBUG LOG:
Request: POST [/dynamicObject/search]
    Matching endpoint-handlers: [BEFORE=*, POST=/dynamicObject/search]
    Headers: {Origin=http://localhost:20080, Accept=*/*, Connection=keep-alive, User-Agent=Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.150 Safari/537.36, Referer=http://localhost:20080/, Sec-Fetch-Site=same-site, Sec-Fetch-Dest=empty, Host=localhost:19021, Pragma=no-cache, Accept-Encoding=gzip, deflate, br, Sec-Fetch-Mode=cors, sec-ch-ua="Chromium";v="88", "Google Chrome";v="88", ";Not A Brand";v="99", sec-ch-ua-mobile=?0, Cache-Control=no-cache, Accept-Language=de-DE,de;q=0.9,en-US;q=0.8,en;q=0.7, Content-Length=15, Content-Type=application/json}
    Cookies: {}
    Body: {"name":"Test"}
    QueryString: null
    QueryParams: {}
    FormParams: {{"name":"Test"}=[]}
Response: [200], execution took 8.57 ms
    Headers: {Server=Javalin, Access-Control-Allow-Origin=http://localhost:20080, Access-Control-Allow-Credentials=true, Date=Tue, 16 Feb 2021 16:46:02 GMT, Content-Type=application/json}
    Body is 59 bytes (starts on next line):
    {"result":"fail","error":"Missing or wrong 'definitionId'"}
----------------------------------------------------------------------------------

My Javalin version: 3.9.1