MyThinkPond

On Java, Python, Groovy, Grails, Spring, Node.js, Linux, Arduino, ARM, Embedded Devices & Web

Archive for the ‘Java’ Category

Java Programming Language

« Previous Entries

Grails 2.3.5 - grails stop-app - does not stop the app running via run-app

Posted by Venkatt Guhesan on February 2, 2014

If you’re using Grails 2.3.X and you’re developing, most likely you’re running your app like this:

grails run-app
#in one command-prompt/shell-terminal and
grails stop-app
#in another command-prompt/shell-terminal

With the latest version of Grails (version 2.3.5), the stop-app say:

grails stop-app
| Server Stopped
# But nothing happens and the server-process continues to run#

Here’s an undocumented fix that can come in handy:

# On terminal/command-prompt #1
# Run the way you do today
grails run-app
# On terminal/command-prompt #2, change-directory (cd) to the root folder where you have your Grails project
# Create a file with a file-name ".kill-run-app"
# For Linux (*Nix) environments
touch .kill-run-app
# For Windows where you do not have 'touch' command do the following instead
echo hello > .kill-run-app
# Wait for a few seconds and Grails will kill the app that's running

Now you can resume with starting a new instance of “grails run-app”.

Cheers & Happy Coding!

Posted in Grails, Groovy, Java | Tagged: , , , , | Leave a Comment »

Grails - Adding JavaScript to bottom of page

Posted by Venkatt Guhesan on February 2, 2014

In Grails using the templating (Sitemesh) if you were to include per-page JavaScript resources then it shows up much earlier in the layout content as part of the <g:layoutBody>

Here is an example illustrating the problem:

SamplePage.gsp

<!DOCTYPE html>
<html>
<head>
<meta name="layout" content="layoutPage"/>
<head>MyThinkPond.com Custom Page</head>
...
</head>
<body>
Some this page content
<script type="text/javascript" src="${request.contextPath}js/samplePage.js"></script>
</body>
</html>

and the layout page (layoutPage.gsp)

<!DOCTYPE html>
<html>
<head>
<title><g:layoutTitle default="MyThinkPond.com"/></title>
...
</head>
<body>
<div>
Some template (header) content
<g:layoutBody/>
</div>
<!-- Common JS Files -->
<script type="text/javascript" src="${request.contextPath}js/common.js"></script>
<!-- Begin: Custom Page JavaScript Should Go Here -->
<!-- End: Custom Page JavaScript Should Go Here -->
</body>
</html>

results in the following page in browser

<!DOCTYPE html>
<html>
<head>
<titleMyThinkPond.com Custom Page</title>
...
</head>
<body>
<div>
Some template (header) content
Some this page content
<script type="text/javascript" src="${request.contextPath}js/samplePage.js"></script>
</div>
<!-- Common JS Files -->
<script type="text/javascript" src="${request.contextPath}js/common.js"></script>
<!-- Begin: Custom Page JavaScript Should Go Here -->
<!-- End: Custom Page JavaScript Should Go Here -->
</body>
</html>

You can see that the JavaScript is included as part of the body and not at the bottom.

Here’s how you resolve this issue:

In your custom page, define a content block like this:

SamplePage.gsp

<!DOCTYPE html>
<html>
<head>
<meta name="layout" content="layoutPage"/>
<head>MyThinkPond.com Custom Page</head>
...
</head>
<body>
Some this page content
<content tag="javascript">
<script type="text/javascript" src="${request.contextPath}js/samplePage.js"></script>
</content>
</body>
</html>

In your template layout page add the content block to the bottom as needed like this:
layoutPage.gsp

<!DOCTYPE html>
<html>
<head>
<title><g:layoutTitle default="MyThinkPond.com"/></title>
...
</head>
<body>
<div>
Some template (header) content
<g:layoutBody/>
</div>
<!-- Common JS Files -->
<script type="text/javascript" src="${request.contextPath}js/common.js"></script>
<!-- Begin: Custom Page JavaScript Should Go Here -->
<g:pageProperty name="page.javascript"/>
<!-- End: Custom Page JavaScript Should Go Here -->
</body>
</html>

This will extract the JavaScript portion from samplePage and insert at the bottom of the layoutPage.

Here is the result of this magic in a page in the browser:

<!DOCTYPE html>
<html>
<head>
<titleMyThinkPond.com Custom Page</title>
...
</head>
<body>
<div>
Some template (header) content
Some this page content
</div>
<!-- Common JS Files -->
<script type="text/javascript" src="${request.contextPath}js/common.js"></script>
<!-- Begin: Custom Page JavaScript Should Go Here -->
<script type="text/javascript" src="${request.contextPath}js/samplePage.js"></script>
<!-- End: Custom Page JavaScript Should Go Here -->
</body>
</html>

You can see that the page specific JavaScript content got added towards the bottom as you intended it to be.

If this article has helped you, please add this article to your favorite social links so that others may also find this article.

Cheers & Happy Coding!

Posted in Grails, Groovy, Java | Tagged: , , , | 1 Comment »

Grails 2.X .gitignore file

Posted by Venkatt Guhesan on November 16, 2013

Grails

With a new Grails 2.X project you run into challenges on which folders to check-in into a GIT repository. You want to remove any non-essential files that Grails can rebuild at run-time. And if you are using either GITHub or BitBucket for your GIT repo’s the default .gitignore file created or provided by GITHub is setup for configured for a Grails 1.X project and not a Grails 2.X project.

 

 

 

So here are a few simple steps to help you create the correct .gitignore file for a Grails 2.X project:

Step-1: Create the following .gitignore file under the root Grails project folder:

*.iws
*Db.properties
*Db.script
.settings
.classpath
.project
.idea
eclipse
stacktrace.log
target
target-eclipse
/plugins
/web-app/plugins
/web-app/WEB-INF/classes
web-app/WEB-INF/tld/c.tld
web-app/WEB-INF/tld/fmt.tld

Step-2: Git does not allow you to check in empty (but essential folders). To avoid this you can run the following command:

find . -type d -empty -exec touch {}/.gitignore ;

The above command creates a empty “.gitignore” file below all folders. And since you now have non-empty folders, you can now check them in into Git so that if you check-out/clone the project in the future, you will have those essential but empty folders.

If you find this article useful, Tweet me on your Twitter account or +1 me on Google-Plus so that others can also benefit from this information.

Cheers

Posted in Grails, Groovy, Java, SourceControl - GIT | Tagged: , , , , | 2 Comments »

Working with zeromq (0mq), Java, JZMQ on a CentOS platform

Posted by Venkatt Guhesan on June 24, 2013

Recently I decided to port some of my development using ZeroMQ onto my CentOS development machine and I ran into some challenges. I’m documenting those challenges so that if someone else runs into the same pitfalls I did, they can avoid it.

In this example today, we will work with the first “HelloWorld” examples in the ZeroMQ guide found here. I added a few modifications to the sample such as a package name and a try-catch around the Thread and an exception.tostring() to display any stack-trace.

Source code for src/zmq/hwserver.java

package zmq;
import java.io.PrintWriter;
import java.io.StringWriter;
import org.zeromq.ZMQ;
//
// Hello World server in Java
// Binds REP socket to tcp://*:5555
// Expects "Hello" from client, replies with "World"
//
public class hwserver {
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		ZMQ.Context context = ZMQ.context(1);
		// Socket to talk to clients
		ZMQ.Socket socket = context.socket(ZMQ.REP);
		socket.bind ("tcp://*:5555");
		try {
			while (!Thread.currentThread ().isInterrupted ()) {
				byte[] reply = socket.recv(0);
				System.out.println("Received Hello");
				String request = "World" ;
				socket.send(request.getBytes (), 0);
				Thread.sleep(1000); // Do some 'work'
			}
		} catch(Exception e) {
			StringWriter sw = new StringWriter();
			PrintWriter pw = new PrintWriter(sw);
			e.printStackTrace(pw);
			System.out.println(sw.toString());
		}
		socket.close();
		context.term();
	}
}

Similarly, source code for the client, src/zmq/hwclient.java

package zmq;
import org.zeromq.ZMQ;
public class hwclient {
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		ZMQ.Context context = ZMQ.context(1);
		// Socket to talk to server
		System.out.println("Connecting to hello world server");
		ZMQ.Socket socket = context.socket(ZMQ.REQ);
		socket.connect ("tcp://localhost:5555");
		for(int requestNbr = 0; requestNbr != 10; requestNbr++) {
			String request = "Hello" ;
			System.out.println("Sending Hello " + requestNbr );
			socket.send(request.getBytes (), 0);
			byte[] reply = socket.recv(0);
			System.out.println("Received " + new String (reply) + " " + requestNbr);
		}
		socket.close();
		context.term();
	}
}

Now that you have the sample code, how do you compile using the ZeroMQ?

Assumption: You have installed Java (1.7 or above)

Step-1: Installing ZeroMQ onto CentOS [Following steps are performed under root account]

  1. Install “Development Tools” if it’s not already installed on your CentOS as root: yum groupinstall “Development Tools”
  2. Download the “POSIX tarball” ZeroMQ source code onto your CentOS development machine from here. At the time of writing this article, ZeroMQ version 3.2.3 was the stable release. You might want to download the latest stable release.
  3. Unpack the .tar.gz source archive.
  4. Run ./configure, followed by “make” then “make install“.
  5. Run ldconfig after installation.

Step-2: Installing a Language Binding for Java. In this case, we will use JZMQ from https://github.com/zeromq/jzmq

  1. Download the latest stable release from GITHub link above. (git clone git://github.com/zeromq/jzmq.git)
  2. Change directory, cd jzmq
  3. Compile and Install: 
    ./autogen.sh
./configure
make
make install
  4. Where did it install? 
    # JAR is located here: /usr/local/share/java/zmq.jar
# .so link files are located here: /usr/local/lib
  5. Important Step: Add /usr/local/lib to a line in /etc/ld.so.conf (here is my copy after editing) 
    include ld.so.conf.d/*.conf
/usr/local/lib
  6. Reload “ldconfig“. This clears the cache.

 

Step-3: Compile and run the Java examples above.

cd ~/dev/zeromq/example/
# Compile hwserver.java
javac -classpath  /usr/local/share/java/zmq.jar ./zmq/hwserver.java
# Compile hwclient.java
javac -classpath  /usr/local/share/java/zmq.jar ./zmq/hwclient.java
# Run hwserver in a separate prompt
java -classpath .: /usr/local/share/java/zmq.jar -Djava.library.path=/usr/local/lib zmq.hwserver
# Run hwclient in a seperate prompt
java -classpath .:/usr/local/share/java/zmq.jar -Djava.library.path=/usr/local/lib zmq.hwclient

Output on the hwserver console:

Received Hello
Received Hello
Received Hello
Received Hello
Received Hello
Received Hello
Received Hello
Received Hello
Received Hello
Received Hello

output on the hwclient console:

Connecting to hello world server
Sending Hello 0
Received World 0
Sending Hello 1
Received World 1
Sending Hello 2
Received World 2
Sending Hello 3
Received World 3
Sending Hello 4
Received World 4
Sending Hello 5
Received World 5
Sending Hello 6
Received World 6
Sending Hello 7
Received World 7
Sending Hello 8
Received World 8
Sending Hello 9
Received World 9

Few interesting points to note are as follows:

  • What happens if you started the client first and then the server? Well, the client waits until the server becomes available (or in other words, until some process connects to socket port 5555) and then sends the message. When you say socket.send(…), ZeroMQ actually enqueues a message to be sent later by a dedicated communication thread and this thread waits until a bind on port 5555 happens by “server”.
  • Also observe that the “server” is doing the connecting, and the “client” is doing the binding.

What is ZeroMQ (ØMQ)?

(Excerpt from the ZeroMQ website!)

ØMQ (also seen as ZeroMQ, 0MQ, zmq) looks like an embeddable networking library but acts like a concurrency framework. It gives you sockets that carry atomic messages across various transports like in-process, inter-process, TCP, and multicast. You can connect sockets N-to-N with patterns like fanout, pub-sub, task distribution, and request-reply. It’s fast enough to be the fabric for clustered products. Its asynchronous I/O model gives you scalable multicore applications, built as asynchronous message-processing tasks. It has a score of language APIs and runs on most operating systems. ØMQ is from iMatix and is LGPLv3 open source.

If you find this article useful, please subscribe to my blog and/or share my link with others.

Posted in Java, ZeroMQ | Tagged: , , , , , | 1 Comment »

Grails - Groovy - Alternative to HttpBuilder - adding headers to your HTTP request

Posted by Venkatt Guhesan on October 24, 2011

Developing with Grails and Groovy can be a blessing and and pain all at the same time. The development moves at a rapid rate but when you decide to include libraries that depend on other libraries, your pain starts to build up. For example, when you include the module “HttpBuilder”in your project you may run into issues with Xerces and xml-apis, especially when you attempt to deploy the WAR file under Tomcat. These libraries are included as part of Tomcat and so an older version of those classes may give you a heartburn.

If your objective is to use some raw HTTP classes to create your requests and responses, then you can use the basic URL class to do most of the raw connection options. Although using HttpBuilder makes it a clean implementation, the URL class gives you very similar power without all the overhead of including the dependency classes.

def urlConnect = new URL(url)
def connection = urlConnect.openConnection()
//Set all of your needed headers
connection.setRequestProperty("X-Forwarded-For", "<your ip address>")
if(connection.responseCode == 200){
responseText = connection.content.text
}
else{
println "An error occurred:"
println connection.responseCode
println connection.responseMessage
}

So the trick to the Groovy URL class is to use the “openConnection()” method and then gain access to some of the raw functionality.

Cheers.

Posted in Grails, Groovy, Uncategorized | Tagged: , , , , | 7 Comments »

Grails H2 Database 1.4.M1 Issue

Posted by Venkatt Guhesan on August 28, 2011

I’ve noticed a peculiar behavior that I’m documenting here for others. I’m using Grails 1.4.M1 and it bundles with it H2 database version [H2 1.2.147 (2010-11-21)]

If you decide to run H2 in a server mode, you would most likely download the latest version of H2 Database from the website. As of writing this article, the stable version of H2 is [H2 1.3.158 (2011-07-17)].

Issue: If you run your Grails application using 1.2.147 and your external H2 database happens to be 1.3.158, then the SELECT’s work fine but when you run INSERT or UPDATE statements, they are not committed.

When I switched the H2 version to 1.2.147, then the <DOMAIN>.save() worked fine.

 

Posted in Grails | Tagged: , , | Leave a Comment »

Java Tools for Source Code Optimization and Analysis

Posted by Venkatt Guhesan on July 14, 2011

Below is a list of some tools that can help you examine your Java source code for potential problems:

1. PMD from http://pmd.sourceforge.net/
License: PMD is licensed under a “BSD-style” license

PMD scans Java source code and looks for potential problems like:

* Possible bugs - empty try/catch/finally/switch statements
* Dead code - unused local variables, parameters and private methods
* Suboptimal code - wasteful String/StringBuffer usage
* Overcomplicated expressions - unnecessary if statements, for loops that could be while loops
* Duplicate code - copied/pasted code means copied/pasted bugs

You can download everything from here, and you can get an overview of all the rules at the rulesets index page.

PMD is integrated with JDeveloper, Eclipse, JEdit, JBuilder, BlueJ, CodeGuide, NetBeans/Sun Java Studio Enterprise/Creator, IntelliJ IDEA, TextPad, Maven, Ant, Gel, JCreator, and Emacs.

2. FindBug from http://findbugs.sourceforge.net
License: L-GPL

FindBugs, a program which uses static analysis to look for bugs in Java code. And since this is a project from my alumni university (IEEE - University of Maryland, College Park - Bill Pugh) , I have to definitely add this contribution to this list.

3. Clover from http://www.cenqua.com/clover/
License: Free for Open Source (more like a GPL)

Measures statement, method, and branch coverage and has XML, HTML, and GUI reporting. and comprehensive plug-ins for major IDEs.

* Improve Test Quality
* Increase Testing Productivity
* Keep Team on Track

Fully integrated plugins for NetBeans, Eclipse , IntelliJ IDEA, JBuilder and JDeveloper. These plugins allow you to measure and inspect coverage results without leaving the IDE.
Seamless Integration with projects using Apache Ant and Maven. * Easy integration into legacy build systems with command line interface and API.
Fast, accurate, configurable, detailed coverage reporting of Method, Statement, and Branch coverage.
Rich reporting in HTML, PDF, XML or a Swing GUI
Precise control over the coverage gathering with source-level filtering.
Historical charting of code coverage and other metrics.
Fully compatible with JUnit 3.x & 4.x, TestNG, JTiger and other testing frameworks. Can also be used with manual, functional or integration testing.

4. Macker from http://innig.net/macker/
License: GPL

Macker is a build-time architectural rule checking utility for Java developers. It’s meant to model the architectural ideals programmers always dream up for their projects, and then break — it helps keep code clean and consistent. You can tailor a rules file to suit a specific project’s structure, or write some general “good practice” rules for your code. Macker doesn’t try to shove anybody else’s rules down your throat; it’s flexible, and writing a rules file is part of the development process for each unique project.

5 EMMA from http://emma.sourceforge.net/
License: EMMA is distributed under the terms of Common Public License v1.0 and is thus free for both open-source and commercial development.

Reports on class, method, basic block, and line coverage (text, HTML, and XML).

EMMA can instrument classes for coverage either offline (before they are loaded) or on the fly (using an instrumenting application classloader).

Supported coverage types: class, method, line, basic block. EMMA can detect when a single source code line is covered only partially.

Coverage stats are aggregated at method, class, package, and “all classes” levels.

Output report types: plain text, HTML, XML. All report types support drill-down, to a user-controlled detail depth. The HTML report supports source code linking.

Output reports can highlight items with coverage levels below user-provided thresholds.

Coverage data obtained in different instrumentation or test runs can be merged together.

EMMA does not require access to the source code and degrades gracefully with decreasing amount of debug information available in the input classes.

EMMA can instrument individial .class files or entire .jars (in place, if desired). Efficient coverage subset filtering is possible, too.

Makefile and ANT build integration are supported on equal footing.

EMMA is quite fast: the runtime overhead of added instrumentation is small (5-20%) and the bytecode instrumentor itself is very fast (mostly limited by file I/O speed). Memory overhead is a few hundred bytes per Java class.

EMMA is 100% pure Java, has no external library dependencies, and works in any Java 2 JVM (even 1.2.x).

6. XRadar from http://xradar.sourceforge.net/
License: BSD (me thinks)

The XRadar is an open extensible code report tool currently supporting all Java based systems. The batch-processing framework produces HTML/SVG reports of the systems current state and the development over time - all presented in sexy tables and graphs.

The XRadar gives measurements on standard software metrics such as package metrics and dependencies, code size and complexity, code duplications, coding violations and code-style violations.

7. Hammurapi from Hammurapi Group
License: (if anyone knows the license for this email me Venkatt.Guhesan at Y! dot com)

Hammurapi is a tool for execution of automated inspection of Java program code. Following the example of 282 rules of Hammurabi’s code, we are offered over 120 Java classes, the so-called inspectors, which can, at three levels (source code, packages, repository of Java files), state whether the analysed source code contains violations of commonly accepted standards of coding.

Relevant Links:
http://en.sdjournal.org/products/articleInfo/93
http://wiki.hammurapi.biz/index.php?title=Hammurapi_4_Quick_Start

8. Relief from http://www.workingfrog.org/
License: GPL

Relief is a design tool providing a new look on Java projects. Relying on our ability to deal with real objects by examining their shape, size or relative place in space it gives a “physical” view on java packages, types and fields and their relationships, making them easier to handle.

9. Hudson from http://hudson-ci.org/
License: MIT

Hudson is a continuous integration (CI) tool written in Java, which runs in a servlet container, such as Apache Tomcat or the GlassFish application server. It supports SCM tools including CVS, Subversion, Git and Clearcase and can execute Apache Ant and Apache Maven based projects, as well as arbitrary shell scripts and Windows batch commands.

10. Cobertura from http://cobertura.sourceforge.net/
License: GNU GPL

Cobertura is a free Java tool that calculates the percentage of code accessed by tests. It can be used to identify which parts of your Java program are lacking test coverage. It is based on jcoverage.

11. SonarSource from http://www.sonarsource.org/ (recommended by Vishwanath Krishnamurthi - thanks)
License: LGPL

Sonar is an open platform to manage code quality. As such, it covers the 7 axes of code quality:

Architecture & Design, Duplications, Unit Tests, Complexity, Potential bugs, Coding rules, Comments.

(Article was originally published on my first blog at blogspot.com)

Posted in Code Analysis, Java | Tagged: , , | 2 Comments »

Not all Tomcat 6 classloaders must be equal

Posted by Venkatt Guhesan on July 1, 2011

Today, while doing some Grails development I came across a peculiar issue that perplexed me and I’m documenting it for all others to benefit. (Also see my other blog from today for the issue that started this journey).

Here are my specifications:

Development Machine

  • Windows-7, 64-bit
  • java version “1.6.0_24”
    Java(TM) SE Runtime Environment (build 1.6.0_24-b07)
    Java HotSpot(TM) 64-Bit Server VM (build 19.1-b02, mixed mode)
  • Grails 1.4.0.M1
  • Tomcat - apache-tomcat64-6.0.32

Local Deployment Server

  • Windows Vista, 32-bit
  • java version “1.6.0_26”
    Java(TM) SE Runtime Environment (build 1.6.0_26-b03)
    Java HotSpot(TM) Client VM (build 20.1-b02, mixed mode, sharing)
  • Grails (does not matter since I’ll be deploying a WAR)
  • Tomcat - apache-tomcat-6.0.32 (32-bit version of Tomcat)

Since the issue we are taking about deals with Grails, let’s get into he details of how I ended up with the WAR. In Grails, I issued the following command:

>grails war abcdefg.war

This creates a war file. When deployed under the 64-bit Tomcat, no issues. But when deployed under the 32-bit Tomcat. I was getting the

Jul 1, 2011 10:08:25 AM org.apache.catalina.core.StandardContext start
SEVERE: Error listenerStart

(See my previous article on how I enabled debugging to get to the root cause of the issue.)

But after some debugging, what it boiled down to was a “Class Cannot Be Found” error:

Jul 1, 2011 11:29:25 AM org.apache.catalina.core.StandardContext listenerStart
SEVERE: Error configuring application listener of class org.codehaus.groovy.grails.web.util.Log4jConfigListener
java.lang.ClassNotFoundException: org.codehaus.groovy.grails.web.util.Log4jConfigListener

In examining the war file, the JAR file named “grails-web-1.4.0.M1.jar” under the “/WEB-INF/lib” does not contain the needed “Log4jConfigListener” class under “grails-web-1.4.0.M1.jar\org\codehaus\groovy\grails\web\util\”

But clearly this class is inside this other JAR file named “grails-plugin-logging-1.4.0.M1.jar” under “\org\codehaus\groovy\grails\web\util\”.

And this identical war file works under the 64-bit Tomcat but not under the 32-bit Tomcat.

So how did I resolve the issue? I upgraded my 32-bit box to Tomcat 7.0 and this made it work. But clearly, there is an underlying issue with the class-loader under the 32-bit Tomcat 6.0.32.

Maybe someone reading this will have the answer to this issue.

Cheers!

Posted in Grails, Groovy, Java, Tomcat, web development | Tagged: , , , , | Leave a Comment »

Tomcat 6+: Infamous “SEVERE: Error listenerStart” message - How-To debug this error?

Posted by Venkatt Guhesan on July 1, 2011

I’m sure if you have been developing with Java and Tomcat for sometime, you are likely to run into the infamous debug error.

SEVERE: Error listenerStart

You will most likely start Googling it trying to find out what the heck is going on. And in trying to see the extended logging on what that “listenerStart” error means. After some lucky searches, you will see links asking you to drop a “log4j.properties” file under ‘/WEB-INF/classes’ directory inside your WAR to help debug which one of the listeners is throwing this crazy error.

Well, this advise will most likely work for you if you are developing under an earlier version of Tomcat. If you are using versions 6.0 or above then continue to read on…

In Tomcat 6 or above, the default logger is the”java.util.logging” logger and not Log4J. So if you are trying to add a “log4j.properties” file - this will NOT work. The Java utils logger looks for a file called “logging.properties” as stated here:
http://tomcat.apache.org/tomcat-6.0-doc/logging.html

So to get to the debugging details create a “logging.properties” file under your”/WEB-INF/classes” folder of your WAR and you’re all set.

And now when you restart your Tomcat, you will see all of your debugging in it’s full glory!!!

Sample logging.properties file:

org.apache.catalina.core.ContainerBase.[Catalina].level = INFO
org.apache.catalina.core.ContainerBase.[Catalina].handlers = java.util.logging.ConsoleHandler

and you will most likely see a “class-not-found” exception. ;-)

Look at the bright side, you’re now one step closer to the solution.

Happy coding!

Posted in Grails, Groovy, GWT, Java, Spring, Spring Framework, Tomcat, web development | Tagged: , , , , , | 25 Comments »

How-To: Turn off Firefox browser cache during development

Posted by Venkatt Guhesan on June 22, 2011

Sometimes (when your are developing) you may want to force fetching all content fresh all the time including images, resources such as style sheet etc. To facilitate this you can do the following:

  1. Open a new window or tab in Firefox.
  2. Type about:config in the address bar.
  3. Search for “cache” in the search bar and look for network.http.use-cache in the filtered results.
  4. Double-click it will toggle it from “true” to “false”. Default should be “true”.

And you’re all set.

Sometime you want to force the cache on one particular page\request. You can do that by holding the “Ctrl” key while clicking reload or F5.

Cheers

Posted in web development | Tagged: , | 2 Comments »

« Previous Entries
 
Follow

Get every new post delivered to your Inbox.

Join 149 other followers