scala-news-reader

rss/atom news reader in scala

git clone https://9o.is/git/scala-news-reader.git

ErrorHandler.scala

(1899B)

      1 package com.joereader
      2 package config
      3 
      4 import model.User
      5 
      6 import net.liftweb._
      7 import common.{Loggable, MDC}
      8 import http.{Factory, LiftRules, RedirectResponse, Req, S, XhtmlResponse}
      9 import util.Props
     10 
     11 object ErrorHandler extends Factory with Loggable {
     12   // config
     13   val errorUrl = new FactoryMaker[String](Site.error.url) {}
     14 
     15   def init(): Unit = {
     16     LiftRules.exceptionHandler.prepend {
     17       case (Props.RunModes.Development, r, e) =>
     18         logException(r, e)
     19         XhtmlResponse(
     20           <html>
     21             <body>Exception occured while processing
     22               {r.uri}<pre>
     23               {showException(e)}
     24             </pre>
     25             </body>
     26           </html>,
     27           S.htmlProperties.docType,
     28           List("Content-Type" -> "text/html; charset=utf-8"),
     29           Nil,
     30           500,
     31           S.ieMode
     32         )
     33       case (_, r, e) =>
     34         logException(r, e)
     35         RedirectResponse(errorUrl.vend)
     36     }
     37   }
     38 
     39   /*
     40    * Log the exception with some user info.
     41    */
     42   def logException(r: Req, e: Throwable) {
     43     import java.net.InetAddress
     44     val srvr = InetAddress.getLocalHost.getHostName
     45 
     46     MDC.put(("UserId", User.currentUserId openOr "GUEST"))
     47     MDC.put(("Username", User.currentUser.map(_.username.is) openOr "GUEST"))
     48     MDC.put(("User Agent", r.userAgent openOr "UNKNOWN"))
     49     MDC.put(("Server", srvr))
     50     logger.error("Exception occurred while processing %s".format(r.uri), e)
     51   }
     52 
     53   /**
     54    * A utility method to convert an exception to a string of stack traces
     55    * @param le the exception
     56    *
     57    * @return the stack trace
     58    */
     59   def showException(le: Throwable): String = {
     60     val ret = "Message: " + le.toString + "\n\t" +
     61       le.getStackTrace.map(_.toString).mkString("\n\t") + "\n"
     62 
     63     val also = le.getCause match {
     64       case null => ""
     65       case sub: Throwable => "\nCaught and thrown by:\n" + showException(sub)
     66     }
     67 
     68     ret + also
     69   }
     70 }