Wednesday, November 27, 2013

How to revoke access to tables prior to postgres 9.0

SELECT 'REVOKE SELECT ON TABLE ' || relname || ' FROM some_user;' FROM pg_class JOIN pg_namespace ON pg_namespace.oid = pg_class.relnamespace WHERE nspname = 'public';

Thursday, September 5, 2013

Postgres grant read only

Prior to postgres 9.0 you can use this:

 SELECT 'GRANT SELECT ON ' || relname || ' TO xxx;'  a
 FROM pg_class JOIN pg_namespace ON pg_namespace.oid = pg_class.relnamespace  
 WHERE nspname = 'public' AND relkind IN ('r', 'v')  

Postgres 9+ you can use this:



Thursday, August 15, 2013

Blocked loading mixed active content


With the latest versions of firefox, a javascript file fail to load from an external site such as google using the following code:

 <script type="text/javascript" src=""></script>  

The connection was secure running on HTTPS. However the connection to load the javascript file was not secure running purely on HTTP.


To get the javascript file to load properly I simply changed the SRC URL to use HTTPS as shown below:

 <script type="text/javascript" src=""></script>  

Monday, August 5, 2013

ClassFormatException Invalid byte tag in constant pool: 60 with Grails in Tomcat 7.0.42

The Problem

I encountered this error when deploying my grails application to the latest version of Tomcat 7.0.42.

The stacktrace is shown below:

 SEVERE: Unable to process Jar entry [com/ibm/icu/impl/data/LocaleElements_zh__PINYIN.class] from Jar [jar:file:/usr/local/apache-tomcat-7.0.42/webapps/mutations/WEB-INF/lib/icu4j-2.6.1.jar!/] for annohas been forcibly unregistered.  
 org.apache.tomcat.util.bcel.classfile.ClassFormatException: Invalid byte tag in constant pool: 60  
     at org.apache.tomcat.util.bcel.classfile.Constant.readConstant(  
     at org.apache.tomcat.util.bcel.classfile.ConstantPool.<init>(  

The offending jar file was the

The Solution

I updated the BuildConfig.groovy file to remove any dependencies to the offending JAR file and updated the dependency to use the latest version of the icu4j which at the time was version 51.1. To do that I inserted this code:

   inherits("global") {  
           excludes "icu4j"  
   dependencies {  
           runtime ''  


Grails version: 2.2.4
Tomcat version: 7.0.42

Monday, May 13, 2013

HTML5 localStorage isolation

HTML5 localStorage isolation

I've recently started using one of HTML5's new features of local browser storage, however, when I started using it in my development environment, I noticed that whenever my domain changed, the values put into storage could not be retrieved.

That is, localStorage is isloated by the domain

For example, if my domain was localhost then I changed the web address to be my IP address for example, then there will be separate instances of localStorage for each domain even though they are pointing to the same web server.

Unforutnately, a lot of books and websites, fail to mention this



Monday, January 21, 2013

Some of your private key files are encrypted for security reasons

To get rid of passphrase when restarting Apache HTTPD use the following command:

openssl rsa -in -out