sobota 27. dubna 2013

Raspberry PI - Soft-float Debian not booting

File start.elf not helped ? 
I searched for solution when my raspberry with soft-float not boot. First solution for this problem I found article about changing the file start.elf from booting section of Raspbian "wheezy". I did not work for me.

Solution
First you need to create backup of booting sector of Raspbian(it is the one with some files ending *.elf). Than create bootable sd card with soft-float debian (supported JVM oracle). The trick that for for me I replaced files below from backuped Raspbian wheezy.

start.elf
bootcode.bin

It works for me. I hope that who faced the same problem helped him.

Tips

sobota 11. února 2012

Log4j - logging into N files based on custom filter

Why ?
I was dealing with log4j and logging into N files. The main idea was to append for each thread Its own logger with different file. I realized that there are not enough information about that so I decided to write my current experience with log4j and custom filtering.

Solution
First, we start with log4j configuration file ( I prefer xml ).

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
<log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
  <appender name="A"  class="org.apache.log4j.FileAppender">
          .......
          <param name="FILE" value="log/A.log" />
          <layout class="org.apache.log4j.PatternLayout">
                  <param name="ConversionPattern" value="...." />
          </layout>
          <filter class="com.log4j.example.CustomFilter">
                  <param name="appender" value="A" />
          </filter>
  </appender>
  <appender name="B"  class="org.apache.log4j.FileAppender">
          .......
          <param name="FILE" value="log/B.log" />
          <layout class="org.apache.log4j.PatternLayout">
                  <param name="ConversionPattern" value="...." />
          </layout>
          <filter class="com.log4j.example.CustomFilter">
                  <param name="appender" value="B" />
          </filter>
  </appender>
<root>
    <appender-ref ref="A"/>
    <appender-ref ref="B"/>
</root>
</log4j:configuration>
At this example there are two appenders with the same filter. If we now run our application the logger will save logs in both log files. However, we want to log some informations into a different files. We came to our CustomFilter.java to see how to deal with.
package com.log4j.example;

import org.apache.log4j.spi.Filter;
import org.apache.log4j.spi.LoggingEvent;

public class CustomFilter extends Filter {
 
 private String appender;

 public void setAppender(String appender) {
  this.appender = appender;
 }

 @Override
 public int decide(LoggingEvent event) {
  if (appender.equals(event.getThreadName())) {
   return Filter.ACCEPT;
  } else if (appender.equals(event.getThreadName())) {
   return Filter.ACCEPT;
  } else {
   return Filter.DENY;
  }
 }
}
As an indetifier I used thread name. There are more possible options It depends on your situation but this was the most suitable for me. I just need to created named thread such as "new Thread(new Runnable(),"A")".

Summarize
I hope this article was helpfull at least for a one person. Thank you for your comments...