Eclipse and Idea hot key bindings

Ok our developers use IDEA and Eclipse. And we do pair programming.
Hmmmn I dont want to learn another set of key bindings...!!

Here is the solution:

Using eclipse keys from idea:

• Idea supports Eclipse key binding built-in;
• you just have to switch to eclipse key bindings using preferences dialog;

Using idea key's from eclipse:

• There is a plugin from http://www.jroller.com/santhosh/entry/intellij_idea_key_scheme_for
• I havent tried it as I am an eclipse guy :)..

Tomcat Exploded war - cut deployment time

The time taken for a webapp to be packaged into a war, deploy and then have it unpackaged in tomcat container can be reduced. Simply have the exploded war deployed.  This could save time for developer!!



Steps to make exploded war deployment:

1. add this under pom.xml >> plugins
             
             
                org.codehaus.mojo
                tomcat-maven-plugin
                1.0-beta-1
               
                    admin
                    admin
                    <url>http://localhost:8080/manager
               
                                          


2. mvn war:exploded tomcat:undeploy tomcat:exploded
--This keeps the war exploded, undeploys the webapp context and copies over the exploded build to tomcat using the tomcat manager.


Also a better option to deploy to different servers and also generating the war ( instead of configuration above):
mvn clean install -Dmaven.test.skip=true  war:exploded tomcat:undeploy tomcat:exploded -Dmaven.tomcat.url=http://localhost:8080/manager -Dtomcat.password=admin -Dtomcat.username=admin


Refer for more http://mojo.codehaus.org/tomcat-maven-plugin/exploded-mojo.html

On Java memory - Spaces - Tomcat PermGen errors

Tomcat out of memory: thread
Better Tomcat Manager
Sun doc on java memory spaces

Etags - request header tags to speed up your site .

An ETag (entity tag) is an HTTP response header returned by an HTTP/1.1 compliant web server.

There are 2 possible implementations :
1. Shallow Etag
           - An MD5 hash is computed for first request from the response content and set in the response header by the web filter.For subsequent requests, the filter retreives the previous etag and checks with the new etag computed using the response content.

Minuses:
   -etag is computed after page is rendered on the server.
   - Doesnt work for pages with dynamic content per request (like date/time).
   Spring 3 has this support. It is called ShallowEtagHeaderFilter.

2. Deep Etag
     -This avoids page computation at a much granular level. Uses hibernate interceptors and is not so straightforward to implement. Spring 3 is yet to support this approach.


References:
infoq article