Search results
Fixing com.sun.tools.javac.Main is not on the classpath Ant compilation error
A few days ago I was setting my development environment up and it involved executing some Apache Ant tasks. I had installed latest Java 7, jdk1.7.0_80 to be exact and Ant 1.8.4, required by the project.
Attempted to compile it and got this output:
C:\Users......\src>ant
Unable to locate tools.jar. Expected to find it in C:\Program Files\Java\jdk1.7.0_80\lib\tools.jar
...
BUILD FAILED
C:\Users\......\build.xml:xxx: The following error occurred while executing this line: .......:
The following error occurred while executing .......: Unable to find a javac compiler;
com.sun.tools.javac.Main is not on the classpath.
Perhaps JAVA_HOME does not point to the JDK.
It is currently set to "C:\Program Files\Java\jdk1.7.0_80"
Troubleshooting high CPU usage in Java applications
1. OVERVIEW
Possible causes of high CPU usage in Java apps might be related to:
- Garbage Collector (GC) executing Major or Full collections too frequently without freeing much memory as a result of a memory leak in one of the applications served by the servlet container or a leak in the servlet container itself.
- GC often executing Major or Full collections (similar to previous suggestion) because in fact, the application needs more memory.
- Issues with the application like resource contention, long running jobs, expensive computation, …
The intention of this entry is to document a simple process to troubleshoot high CPU usage in Java apps once it has been observed that it’s not related to GC.
2. FIND THE JVM PROCESS
ps aux | grep java
tomcat 26551 128 30.9 3946348 1215360 ? Sl 13:43 26:21 /usr/java/latest/bin/java ........ org.apache.catalina.startup.Bootstrap start
A static blog hosted on AWS S3, built with Jekyll and Jenkins
1. OVERVIEW
Creating a blog was in my TODO list for too long, being too ambitious prevented it me from just getting it up. WordPress or Drupal + phpCAS or Java-based blog/CMS + Jasig CAS for Single Sign On between the blog + Asimio.net; it was too complex and time-consuming.
Earlier this year I read Soft Skills: The software developer’s life manual which I found it to be a really interesting book and that was it, I was decided to start a blog, but took a different route than what was suggested, it had to be simple and fun where I would learn something new in the process and after a day of quick research, I decided it to use Jekyll to generate a static blog and hosted it on Amazon S3 since I’m already using a couple of AWS services with Asimio.net.
In this post I’ll detail how to accomplish this and optionally, use Jenkins to implement a Continuous Deployment approach to automatically deploy the blog when new posts become available. It will also serve me as a short how to guide in case I decide to create a static site again.
Asimio.net's Architecture
SIDE PROJECT
Asimio.net is a side project I have been working on for a few years now to try or play with technology that I don’t necessarily use as part of my daily job.
It’s a rental property information services provider that allows to search for vacant properties and registered users to list their properties, upload photos and save searches.