title: how to print custom stacktrace in java logback?
body: <p>Current logback.xml</p>
  
  <pre><code>&lt;appender name="FILEOUT3" class="ch.qos.logback.core.FileAppender"&gt;
      &lt;file&gt;D:/${byDay}.log&lt;/file&gt;
      &lt;append&gt;true&lt;/append&gt;
      &lt;encoder&gt;
          &lt;Pattern&gt;%d{HH:mm:ss} %-5level %msg%replace(%xException){"\n", "&gt;&gt; "}%nopex%n&lt;/Pattern&gt;
      &lt;/encoder&gt;
  &lt;/appender&gt;
  </code></pre>
  
  <p>Current result :</p>
  
  <pre>
  play.api.Configuration$$anon$1: Configuration error[Cannot connect to database [default]]
  >> at play.api.Configuration$.play$api$Configuration$$configError(Configuration.scala:92) ~[play_2.10-2.2.0.jar:2.2.0]
  >> at play.api.Configuration.reportError(Configuration.scala:570) ~[play_2.10-2.2.0.jar:2.2.0]
  >> at play.api.db.BoneCPPlugin$$anonfun$onStart$1.apply(DB.scala:252) ~[play-jdbc_2.10-2.2.0.jar:2.2.0]
  </pre>
  
  <p>I want result :</p>
  
  <pre>
  [12:43:16.454] play.api.Configuration$$anon$1: Configuration error[Cannot connect to database [default]]
  [12:43:16.454]    at play.api.Configuration$.play$api$Configuration$$configError(Configuration.scala:92) ~[play_2.10-2.2.0.jar:2.2.0]
  [12:43:16.454]    at play.api.Configuration.reportError(Configuration.scala:570) ~[play_2.10-2.2.0.jar:2.2.0]
  [12:43:16.454]    at play.api.db.BoneCPPlugin$$anonfun$onStart$1.apply(DB.scala:252) ~[play-jdbc_2.10-2.2.0.jar:2.2.0]
  :
  :
  more 40 lines
  :
  [12:43:16.454]    at play.api.db.BoneCPPlugin$$anonfun$onStart$1.apply(DB.scala:252) ~[play-jdbc_2.10-2.2.0.jar:2.2.0]
  </pre>
  
  <p>IMPORTANT! <br>
  Same Time Print<br></p>
  
  <p>I want know.<br>
  How to change logback.xml?</p>