Reverse Engineer Hibernate Entities from a DB

I may make a use of this on a current object, so I had to google around and this is what I camep up with.

1. Install hibenate-tools for eclipse
    Eclipse -> Help -> Install New Software -> Add
    Location: hibernate-tools
    Site: http://download.jboss.org/jbosstools/updates/stable/helios

                                            \

OK -> Expand Data Services and select Hibernate Tools

                                          

-> Next -> Restart at the prompt.

Create new Java Project with three source folders

-src
-config
-lib

Import the mysql-driver jar to the lib folder and add it to the classpath (in my case mysql-connector-java-5.1.13-bin.jar)

Select the config folder -> File ->New -> Other -> Hibernate Configuration File -> Next -> Next
Fill out the Dialect, the Driver class, the Connection URL, the username and password,
Check Create a console Configuration -> Next

Select the Annotations radio-button

Select the options tag, Select MySQL from the Database Dialect drop-down -> Finish

File -> New -> Other -> Hibernate -> Hibernate Reverse Engineering File -> Next -> Next

Select the console configuration you created in the previous step from the
'Console Configuration' drop-down (in my case hibernate reverse) -> Hit the Refresh button bottom left -> Select the Database Schema from the left -> Hit Include

Finish. You should see two new files in your config folder:

Finally, you want to switch to Hibernate perspective:
Window -> Open Perspective -> Other ->Hibernate

Run ->Hibernate Code Generation -> Hibernate Code Generation Configurations ->
Double click Hibernate Code Generation ->
Select the Console Configuration from the drop-down ->
Select the Output directory as the src dir on the project ->
Select Reverse Engineer from JDBC Connection

Select the Exporters Tab -> Select Both Use Java 5 Syntax and EJB 3 annotations ->
Put a check in Domain Code(.java) -> Apply -> Run

And...BOOM...Now under the src folder you should see a 'default package' with all of your entities:

My Cloudfoundry experience

I finally decided to follow up on my "Congratulations, You have been signed up with Cloudfoundry" email and see if I can go flying in the cloud. I looked at the help doc and started following along.
You'd have to install ruby and ruby gems, unless you opt for the STS plugin. The Cloudfoundry's deploy tool vmc is a gem so the first thing I did was "gem install vmc" as per the help doc.

After that I went on to deploying my hello world grails app. Attached is a screen shot of my dos session:

And sure enough the world's best online donkeys supermarket can be found at:

http://onlinedonkeys.cloudfoundry.com

I didn't have to install a database, I didn't have to write code to talk to a proprietary data source (hint, hint...GAE). It all just magically worked. Thumbs up!

I like the fact that it gives you three options for database - MongoDB and redis besides MySQL.
It also automatically detected that I wanted to deploy a Grails app.
You can also deploy Rails, Node, Sinatra, Spring Roo and JavaWeb.
Happy clouding!

javax.mail.MessagingException: A12 NO Mailbox does not exist, or must be subscribed to

This one has been a long time coming...
One of the apps I have worked on uses Postfix + IMAP for email. One of the users was unable to get to her/his mailbox and in the apps logs for that user we were seeing :


Caused by: javax.mail.MessagingException: A12 NO Mailbox does not exist, or must be subscribed to.;
  nested exception is:
        com.sun.mail.iap.CommandFailedException: A12 NO Mailbox does not exist, or must be subscribed to.
        at com.sun.mail.imap.IMAPFolder.getMessageCount(IMAPFolder.java:1206)
        at com.altair.cls.common.messaging.eis.mail.MailMessageDAO.getMailBoxLineItem(MailMessageDAO.java:1083)
        at com.altair.cls.common.messaging.eis.mail.MailMessageDAO.getMailBoxLineItems(MailMessageDAO.java:1020)
        ... 50 more
Caused by: com.sun.mail.iap.CommandFailedException: A12 NO Mailbox does not exist, or must be subscribed to.
        at com.sun.mail.iap.Protocol.handleResult(Protocol.java:340)
        at com.sun.mail.imap.protocol.IMAPProtocol.status(IMAPProtocol.java:855)
        at com.sun.mail.imap.IMAPFolder.getStatus(IMAPFolder.java:1359)
        at com.sun.mail.imap.IMAPFolder.getMessageCount(IMAPFolder.java:1185)



We give users the ability to create custom mail folders and subfolders. This particular one did create a custom  folder and also a subfolder inside it, so the mailbox on the files system had the likes of:

Then at some point she/he attempted to delete the custom folder "CustomFolder" in this case, but something bleeped in the system and the parent "CustomFolder" was deleted, but the child "CustomFolder.subfolderOfCustomFolder" remained in the filesystem:

So the next time the user attempted to access her/his mailbox, she/he was unable to and the above mentioned exception was showing in the logs. We could not figure out what caused the subfolder to not delete, but deleting the subfolder, in this case "CustomFolder.subfolderOfCustomFolder", from the file system enabled the user to access her/his mailbox again. Hope this helps someone at some point.

Wish list for things to play with after Stir Treck

1. Node.js
2. MongoDB (already played with, but just a little)
3. Finish reading JavaScript The Good Parts (...this is embarrassing, I've had this book for 8 months and it is only 140 pages)
4. Jasmine
5. Sinatra
6. Hadoop

Testing private methods in Java

In a perfect world you shouldn't need to test private methods in Java. If you are doing greenfield and you have committed to Test Driven Development, the unit test you write for your public and protected methods should be robust enough to cover the private methods as well. Legacy code is a different animal. Having to deal with spaghetti code, combined with a fast approaching deadline and the risk and effort in completely refactoring the whole thing, justifies the use of an utility for testing private methods...in my humble opinion that is. Here is one I have used plus an example:

import java.lang.reflect.Method;

public class PrivateMethodTestingUtil {
   
    public static Object invokePrivateMethod(Object objectWithPrivateMethod, String methodName, Class[] classArgs , Object[] objectArgs) throws Exception {   
       
        Method privateMethod = objectWithPrivateMethod.getClass().getDeclaredMethod(methodName, classArgs);
       
        privateMethod.setAccessible(true);   
       
        return privateMethod.invoke(objectWithPrivateMethod, objectArgs);
    }
   
}


example


    @Test
    public void ensureValidatePasswordReturnsTrue() throws Exception{
        
      User user = new User();
      user.setPassword("password");
      user.setConfirmPassword("password");

     String someStringForASecondArg = "secondArg";

      boolean validate = PrivateMethodTestingUtil.invokePrivateMethod(validator,
            "validatePassword", new Class[]{User.class, String.class},
                new Object[]{user, someStringForASecondArg});

        assertTrue(validate);
       
    }


public class Validator {

    public boolean validate(User user) {

          return validatePassword(User, "hello");
    }

    private boolean validatePassword(User user, String secondArg) {

        return true;
    }
}

Java regex to match words with only Alphanumeric and Punctuation characters

The title says it:

 private static final String onlyAlphaNumericAndPunctuationRegex = "[\\p{Alnum}\\p{Punct}]*";

//returns true
"0123!\"#$%&<=~abcijkxyzABC".matches(onlyAlphaNumericAndPunctuationRegex);

//returns false
"hello test space".matches(onlyAlphaNumericAndPunctuationRegex);

//returns false
"some_àèìòù-ÀÈÌÒÙ_more".matches(onlyAlphaNumericAndPunctuationRegex);


if you need to have at least one character change the regex to:

"[\\p{Alnum}\\p{Punct}]{1,}";

org.apache.abdera.parser.ParseException: com.ctc.wstx.exc.WstxException: Illegal null byte in input stream

Got this at work a couple of weeks ago, just got around putting it out here.
We use abdera1.0 to parse XML from a restful call:

 org.apache.abdera.parser.stax.FOMParser feedParser = new org.apache.abdera.parser.stax.FOMParser();
 InputStream in =new URL("http://randomdonkeys.com/give_me_my_donkey.atom").openStream();
 Document<Feed> feedDoc = feedParser.parse(in);

The .parse call threw the WstxException. After digging around discovered that the abdera1.0 jar has issues with parsing ChunckedInputStream. I was able to get around it by wrapping the InputStream in InputStreamReader:

Document<Feed> feedDoc = feedParser.parse(new InputStreamReader(in));

Hope this helps someone at some point.