title: DailyRollingFileAppender not work
body: <p>I use Log4j to write some log my program.
  I find and read many question and answer in this site, but i can't solve my problem.</p>
  
  <p>Here my code:</p>
  
  <p><strong>1. log4j.xml</strong></p>
  
  <pre><code>&lt;appender name="rollingfileAppender" class="org.apache.log4j.DailyRollingFileAppender"&gt;
      &lt;param name="append" value="true"/&gt;
      &lt;param name="file" value="logs/process.log"/&gt;
      &lt;param name="DatePattern" value="'.'yyyy-MM-dd-HH"/&gt;
      &lt;layout class="org.apache.log4j.PatternLayout"&gt;
         &lt;param name="ConversionPattern" value="%d{yyyy-MM-dd HH:mm:ss:SSS} %-5p [%c{1}] %m%n"/&gt;
      &lt;/layout&gt;
  &lt;/appender&gt;
  &lt;root&gt;
      &lt;level value="DEBUG"/&gt;
      &lt;appender-ref ref="rollingfileAppender"/&gt;
      &lt;appender-ref ref="stdout"/&gt;
  &lt;/root&gt;
  </code></pre>
  
  <p></p>
  
  <p><strong>2. My java code</strong></p>
  
  <pre><code>package TestPacket;
  
  import org.apache.log4j.Logger;
  import org.apache.log4j.xml.DOMConfigurator;
  
  
  public class TestLog4jXML {
      static Logger logger = org.apache.log4j.Logger.getLogger(TestLog4jXML.class.getName());
      public TestLog4jXML() {
      }
      public static void main(String[] args) {
          try {
              DOMConfigurator.configure("log4j1.xml");
              logger.trace("Entering application.");
              logger.debug("Debug");
              logger.info("info");
              logger.warn("warn");
              logger.error("error");
              logger.fatal("fatal");
              lungtng();
          } catch (Exception e) {
              e.printStackTrace();
          }
      }
      public static void lungtng()
      {
          logger.fatal("some text here");
          logger.info("hello picaso");
      }
  }
  </code></pre>
  
  <p>And i run my program, with eclipse, windows os.
  But the log file name only: <em>process.log</em> not in daily format: <em>process.log.yyyy-MM-dd-HH</em></p>
  
  <p>Who can explain this to me?</p>