JDK 5 was the default Java version in use, upgraded to JDK1.6.0_21-b06 today and Eclipse started tanking. Starts up fine but after a few minutes would fail with the error 'Internal plug-in action delegate error on creation. PermGen space'. Right, seemed to indicate that I wasn't allocating enough memory for permgen. But the same program works fine with the very same memory settings under JDK 5, so this was definitely an upgrade problem. So much for my support of auto updates :-|
The default setting in eclipse.ini was
--launcher.XXMaxPermSize
256m
-vmargs
-Dosgi.requiredJavaVersion=1.5
-Xms40m
-Xmx256m
And 256m is generally sufficient for permgen, so what gives. Checked the configuration file to confim if the settings had taken effect (Click on Help -> About Eclipse -> Installation Details -> Configuration). Shows up the Xms and Xmx, but no MaxPermGen, hmmm... interesting.
eclipse.vmargs=-Dosgi.requiredJavaVersion=1.5
-Xms40m
-Xmx256m
Googled a bit. The eclipse wiki indicated that it was a bug with Oracle/Sun JDK 1.6.0_21 (had to be my version, duhhh), being tracked as 319514. The bug link is a pretty interesting read.
Apparently, as part of Oracle's rebranding of Sun's products, the Company Name property of the java.exe file, the executable file containing Oracle's JRE for Windows, was updated from "Sun Microsystems" to "Oracle" in Java SE 6u21. Now on Windows, Sun VM is identified using the GetFileVersionInfo API, which reads the company name (present under version details) from jvm.dll or the java executable and compares it against the string "Sun Microsystems". Post update 21, the company name was "Oracle" and the launcher does not recognize this string, hence the -XX:MaxPermSize setting is not honoured.
The workarounds are
- Switch back to '1.6.0_20'
- Change the commandline for launching or add the following line after "-vmargs" to your Eclipse.ini file:-XX:MaxPermSize=256m
- For 32-bit Helios, download the fixed eclipse_1308.dll and place it into (eclipse_home)/plugins/org.eclipse.equinox.launcher.win32.win32.x86_1.1.0.v20100503
- Download and install any of the upgraded versions i.e. version 1.6.0_21-b07 or higher from the java site (alternative link is http://java.sun.com/javase/downloads/index.jsp). Make sure you have b07 or higher by running java -version.
Went with the last option and so far life's good. The MaxPermSize setting shows up under vm options
eclipse.vmargs=-Dosgi.requiredJavaVersion=1.5
-Xms40m
-Xmx256m
-XX:MaxPermSize=256m
But got this bad feeling that when I move to JDK 7, there'll be a newer set of problems cropping up (From the Oracle site: In consideration to Eclipse and other potentially affected users, Oracle has restored the Windows Company Name property value to "Sun Microsystems" in further JDK 6 updates. This value will be changed back to "Oracle" in JDK 7.) Sigh, so much for compatibility.
Monday, December 27, 2010
Monday, June 21, 2010
Google CL rocks
Refer Isaac Truet's post Setup GoogleCL on WinXP if you plan to setup GoogleCL on Windows. Tried it on XP, yet to check on Windows 7.
This post is just to indulge my fantasy of posting a blog from the command line :-)
Command used to post
google blogger post --blog "TechRamblings" --title "Google CL rocks" --tags "python, googlecl, development" googlecl.html
This post is just to indulge my fantasy of posting a blog from the command line :-)
Command used to post
google blogger post --blog "TechRamblings" --title "Google CL rocks" --tags "python, googlecl, development" googlecl.html
Sunday, June 13, 2010
Eclipse Decompiler Plugins
JADClipse plugin worked fine with Eclipse Galileo (3.5) on my old laptop, but failed on the Dell. The funny thing is JAD works fine from the command line, but cuts no ice with Eclipse. Tried by pointing Eclipse to the JADClipse update url, it downloads the jars yes but decompile it does not. Tried an eclipse -clean, still no luck.
All I can assume is JADClipse does't work on 64 bit machines, weird yes, but true.
An option you can choose to go with is JD-Eclipse plugin. Use Eclipse Update Manager to download JD and change the .class association to the JD Class File Editor.
BTW, if interested, steps to follow for setting up JAD with Eclipse on win32 machines.
All I can assume is JADClipse does't work on 64 bit machines, weird yes, but true.
An option you can choose to go with is JD-Eclipse plugin. Use Eclipse Update Manager to download JD and change the .class association to the JD Class File Editor.
BTW, if interested, steps to follow for setting up JAD with Eclipse on win32 machines.
SyntaxHighlighter on Blogger
If you intend to post code snippets on your blog, SyntaxHighlighter is the best option available.
Steps to enable it in your blogpost
1. Download the latest version and unzip in a local folder.
2. Upload all the files to either your domain or to sites.google.com.
3. Edit your template (In blogger, click on Design -> Edit HTML) and paste the following snippet under the closing div tag.
Steps to enable it in your blogpost
1. Download the latest version and unzip in a local folder.
2. Upload all the files to either your domain or to sites.google.com.
3. Edit your template (In blogger, click on Design -> Edit HTML) and paste the following snippet under the closing div tag.
4. And finally, at the start of your code snippet, add the <pre class="brush: js"> tag. Close the code snippet with the corresponding </pre> tag.
Saturday, June 12, 2010
Eclipse Maven Integration - Settings file does not exist
If you're trying to integrate Maven 2x with Eclipse and the following error pops up when installing a Maven project, read on. The error is 'cos Eclipse isn't aware of the Maven setup on your machine, so we set M2_HOME and add that under the classpath variables made available to Eclipse. For good measure, we also setup a local repository for Maven (that's unrelated to the fault below, just a good to have)
1. Navigate to the directory where Maven is installed - e.g. F:\apache-maven-2.2.1. Copy the absolute path. Create a new environment variable M2_HOME and modify the PATH variable
2. Create a new folder 'repository' under M2_HOME.
3. Edit the file settings.xml present under M2_HOME\conf directory. The localRepository tag element would be commented by default. Uncomment this and modify the value to point to the absolute path of the repository folder u just created ( When a jar file is referenced, Maven first looks for it in the local repository, if not found, it downloads the same from the online repository. )
4. Next Eclipse needs to be told the path to the local maven repository. Select Window -> Preferences. On the LHS pane of the popup, select Java -> Build Path -> Classpath Variables. Check if the value under M2_REPO is the same as the localRepository defined in settings.xml. If not, from the LHS pane, select Maven -> User Settings and change the path to the settings.xml under M2_HOME i.e. F:\apache-maven-2.2.1\conf\settings.xml
That's it.
[ERROR] Error executing Maven. [ERROR] The specified user settings file does not exist: C:\Users\xxxxxx\.m2\settings.xml
1. Navigate to the directory where Maven is installed - e.g. F:\apache-maven-2.2.1. Copy the absolute path. Create a new environment variable M2_HOME and modify the PATH variable
M2_Home=F:\apache-maven-2.2.1 PATH=%M2_HOME%\bin;...
2. Create a new folder 'repository' under M2_HOME.
3. Edit the file settings.xml present under M2_HOME\conf directory. The localRepository tag element would be commented by default. Uncomment this and modify the value to point to the absolute path of the repository folder u just created ( When a jar file is referenced, Maven first looks for it in the local repository, if not found, it downloads the same from the online repository. )
F:\apache-maven-2.2.1\repository
4. Next Eclipse needs to be told the path to the local maven repository. Select Window -> Preferences. On the LHS pane of the popup, select Java -> Build Path -> Classpath Variables. Check if the value under M2_REPO is the same as the localRepository defined in settings.xml. If not, from the LHS pane, select Maven -> User Settings and change the path to the settings.xml under M2_HOME i.e. F:\apache-maven-2.2.1\conf\settings.xml
That's it.
Saturday, June 5, 2010
Buzz bookmarklet for Chrome
Got tired of copying urls and posting them in Buzz or using Tweetdeck or the Reader as an intermediary, so started checking out bookmarklets. This one was created by taking the delicious bookmarket as base and the testing has been cursory at best. Ensure that the 'Always show Bookmarks bar' is checked, open Bookmark Manager and create a new bookmark, paste the code below. That's it, good 2 go.
javascript:void(window.open('http://www.google.com/buzz/post?url='+encodeURIComponent(window.location.href)+'&title='+ encodeURIComponent(document.title),'buzzwindow','location=yes, links=no,scrollbars=no,toolbar=no,width=750,height=450'));
Friday, June 4, 2010
OpenID and OAuth - Alike yet different
If I hear one more person use the two terms interchangeably, I'll scream, ergo this post.
The similarities first - Both are open standards and co-exist in the security / identity space. Also both involve the consumer and provider sites communicating with each other using standard HTTP protocols.
I'll start off with a brief description of both, before highlighting the differences.
Let's take OpenID first
OpenID is an open decentralized standard that defines a way for web-based applications to authenticate users with a single identity. So a user does not have to maintain multiple username / password combinations, rather you can use an existing account from one of the OpenID providers to sign in to multiple OpenID-enabled websites.
Chances are you already have an OpenID identity, if you have an account with Google or Yahoo, among others. Enable OpenID with them and get the OpenID identifier which comes in the form of a unique URL. Here Google/Yahoo is the OpenID provider - for a list of OpenID providers click here. You, as a user, can choose a certain OpenID provider today and later switch to another, if you so wish - a perfect decentralized setup.
Next come the consumers - that's simple, any application which is OpenID enabled qualifies. For e.g. Google Apps uses OpenID to achieve SSO - JanRain is one of the OpenID solutions available. A list of OpenID supported sites is available here.
A simple example. Consider a scenario where you wish to comment on a blog using your OpenID identity. To enable OpenID commenting on this blog, I need to select 'Registered Users - includes OpenID' against the 'Who can comment' setting.
Next, follow the steps listed below - that in a nutshell is how OpenID works
1. Select your OpenID provider from the drop down menu next to the 'Sign-in using' option.
2. Next, enter the OpenID URI (Note - only the username is requested here).
3. When you click 'Publish your Comment', you will be redirected to your OpenID provider to authenticate your ID. Here you are prompted to enter your password.
4. When you submit the form, the OpenID provider authenticates your credentials, and redirects you back to the comments page and your comment will be automatically posted. Your comment will appear appear with an OpenID icon to the left of the comment.
The risks associated with using OpenID are:
1. Not all sites support OpenID, but its adoption is expected to grow (I've been hearing that since the last couple of years :-))
2. Single point of failure - If your OpenID password is compromised by phishing, you risk compromising your identity + access to consumer sites.
Now for OAuth
OAuth lets you authorize one website (consumer) to access your data from another website (provider). For e.g. take the recent Seesmic integration of Buzz into their desktop and Web apps - that's OAuth behind the scenes. If you want to authorize Seesmic to get access to your Buzz feeds, Seesmic will redirect you to Buzz which will confirm with you before granting access. Note that if you are not logged into Buzz, you will need to, which is fine. Infinitely better than giving a third party app my Buzz credentials. An alternative is to login using OpenID, but won't muddy the waters with that now :-)
Effectively means - OAuth allows
- Consumers to interact with protected data and
- Providers to enable third party apps access to stored data while protecting account credentials.
Detailed explanation here.
Now, as promised, the diffs -
1. OpenID is more of an authentication mechanism, whereas OAuth deals with open authorization. How so, you ask. Well, OpenID is about the provider site authenticating the user for consumer sites. Whereas OAuth is about the provider site authorizing access to its stored data by the consumer sites. Simple see :-)
2. The OpenID provider holds authentication information (read credentials) and a set of general information which it provides to consumer sites, e.g. registration details to prevent you from having to enter your address details every single time. Whereas in OAuth, the stored data held by the provider is shared with consumer sites.
3. Can they co-exist? Hell, yes. But the preferred method of communication right now is OAuth.
The similarities first - Both are open standards and co-exist in the security / identity space. Also both involve the consumer and provider sites communicating with each other using standard HTTP protocols.
I'll start off with a brief description of both, before highlighting the differences.
Let's take OpenID first
OpenID is an open decentralized standard that defines a way for web-based applications to authenticate users with a single identity. So a user does not have to maintain multiple username / password combinations, rather you can use an existing account from one of the OpenID providers to sign in to multiple OpenID-enabled websites.
Chances are you already have an OpenID identity, if you have an account with Google or Yahoo, among others. Enable OpenID with them and get the OpenID identifier which comes in the form of a unique URL. Here Google/Yahoo is the OpenID provider - for a list of OpenID providers click here. You, as a user, can choose a certain OpenID provider today and later switch to another, if you so wish - a perfect decentralized setup.
Next come the consumers - that's simple, any application which is OpenID enabled qualifies. For e.g. Google Apps uses OpenID to achieve SSO - JanRain is one of the OpenID solutions available. A list of OpenID supported sites is available here.
A simple example. Consider a scenario where you wish to comment on a blog using your OpenID identity. To enable OpenID commenting on this blog, I need to select 'Registered Users - includes OpenID' against the 'Who can comment' setting.
Next, follow the steps listed below - that in a nutshell is how OpenID works
1. Select your OpenID provider from the drop down menu next to the 'Sign-in using' option.
2. Next, enter the OpenID URI (Note - only the username is requested here).
3. When you click 'Publish your Comment', you will be redirected to your OpenID provider to authenticate your ID. Here you are prompted to enter your password.
4. When you submit the form, the OpenID provider authenticates your credentials, and redirects you back to the comments page and your comment will be automatically posted. Your comment will appear appear with an OpenID icon to the left of the comment.
The risks associated with using OpenID are:
1. Not all sites support OpenID, but its adoption is expected to grow (I've been hearing that since the last couple of years :-))
2. Single point of failure - If your OpenID password is compromised by phishing, you risk compromising your identity + access to consumer sites.
Now for OAuth
OAuth lets you authorize one website (consumer) to access your data from another website (provider). For e.g. take the recent Seesmic integration of Buzz into their desktop and Web apps - that's OAuth behind the scenes. If you want to authorize Seesmic to get access to your Buzz feeds, Seesmic will redirect you to Buzz which will confirm with you before granting access. Note that if you are not logged into Buzz, you will need to, which is fine. Infinitely better than giving a third party app my Buzz credentials. An alternative is to login using OpenID, but won't muddy the waters with that now :-)
Effectively means - OAuth allows
- Consumers to interact with protected data and
- Providers to enable third party apps access to stored data while protecting account credentials.
Detailed explanation here.
Now, as promised, the diffs -
1. OpenID is more of an authentication mechanism, whereas OAuth deals with open authorization. How so, you ask. Well, OpenID is about the provider site authenticating the user for consumer sites. Whereas OAuth is about the provider site authorizing access to its stored data by the consumer sites. Simple see :-)
2. The OpenID provider holds authentication information (read credentials) and a set of general information which it provides to consumer sites, e.g. registration details to prevent you from having to enter your address details every single time. Whereas in OAuth, the stored data held by the provider is shared with consumer sites.
3. Can they co-exist? Hell, yes. But the preferred method of communication right now is OAuth.
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