Rick's blog

Find a phrase within any file(s) using grep and exec

2011-12-26T18:48:00.001+02:00

find [dir path] -name "[filename or wildcard]" -exec grep "[the phrase that pays]" {} \;

MySQL

2011-12-15T13:31:00.000+02:00

Getting lazy to look for a column name in some table? Look no further:

SELECT DISTINCT TABLE_NAME FROM information_schema.columns WHERE COLUMN_NAME LIKE '%blabla%' AND TABLE_SCHEMA='YourDatabase';

A tool to generate plain text files with n-characters

2011-12-07T14:21:00.001+02:00

Ideal for those days when you need to test input fields

package com.text;  
 import java.io.BufferedWriter;  
 import java.io.File;  
 import java.io.FileWriter;  
 import java.io.IOException;  
 import java.util.Random;  
 public class Main {  
      private String generateText(int size) {  
           String text = new String();  
           Random r = new Random();  
           while (text.length() &lt; size) {  
                Character c = (char) (r.nextInt(26) + 'a');  
                text += c;  
           }  
           return text;  
      }  
      private void writeFile(int size) {  
           File file = new File("Test_file_of_size_" + size + ".txt");  
           try {  
                if (file.exists()) {  
                     file.delete();  
                }  
                if (!file.exists()) {  
                     file.createNewFile();  
                }  
                FileWriter fw = new FileWriter(file.getName());  
                BufferedWriter bw = new BufferedWriter(fw);  
                bw.write(generateText(size));  
                bw.close();  
           } catch (IOException e) {  
                e.printStackTrace();  
           }  
      }  
      public static void main(String[] args) {  
           new Main().writeFile(1023);  
           new Main().writeFile(1024);  
           new Main().writeFile(1025);  
      }  
 }

renaming file extensions recursively using bash

2011-04-20T21:31:00.000+02:00

find -name "*.JPG" -exec rename 's/JPG/jpg/' *.JPG {} \;

ant mail location/time saver

2011-02-22T15:00:00.003+02:00

make sure you have a javamail.jar in a lib dir. Use ant 1.7.x as ant 1.8.x is fail. Goes through outlook quickly. Make your cron job and have one on me ;)

<?xml version="1.0" encoding="ISO-8859-1"?>
<project name="Script" basedir=".">

<property name="user" value="blanketyblank"/>
<property name="pass" value="blanketyblank"/>

<path id="svnant.classpath">
  <fileset dir="${basedir}/lib">
    <include name="*.jar"/>
  </fileset>
</path> 

<target name="mailMe"  >
  <mail mailhost="db.host.com" mailport="25" subject="status update" 
 user="${user}" password="${pass}" toList="blankety@blank.com">
    <from address="blankety@blank.com"/>
    <message>I'm waiting for the DB restore to finish that I may carry on. </message>
  </mail>
</target>

</project>

JPA/EclipseLink and Glassfish

2010-12-16T22:31:00.005+02:00

Example source code using JSF2, EclipseLink, Glassfish 3, Helios, EJB3: http://svn2.xp-dev.com/svn/JSF-tuts/jsf-blank
Set a connection pool. One per database. Put the DB name after the URL (jdbc:mysql://:3306/dbNameHere)
set the JNDI resource to use this pool. Refer to it in the code.

The jta-data-source must be referred to here, else Glassfish will use its default server

Numeric keypad stopped working in Ubuntu

2010-11-21T06:27:00.000+02:00

My laptop's keypad stopped working. There are two solutions:

System -> Preferences -> keyboard -> uncheck "pointer can be controlled by keypad" under the "Mouse keys" tab
gksudo gedit /usr/share/X11/xkb/compat/complete
and comment out lines for mousekeys and accesx(full) (for full keyboard accessibility purge)
resulting file /usr/share/X11/xkb/compat/complete:
// $XKeyboardConfig$
// $Xorg: complete,v 1.3 2000/08/17 19:54:34 cpqbld Exp $
default xkb_compatibility "complete" {
include "basic"
augment "iso9995"
//augment "mousekeys"
//augment "accessx(full)"
augment "misc"
augment "xfree86"
augment "level5"
};
(http://ubuntuforums.org/showthread.php?p=8609237)

MySQL is broken on Lucid

2010-11-20T09:17:00.001+02:00

A way to fix this is to re-install the packages. A quick way to do that is:

dpkg -l | awk '{print $2}' | grep mysql > installed_packages.txt

apt-get remove `cat installed_packages.txt`
apt-get install `cat installed_packages.txt`

A map test: you can overwrite map values by using the same key

2010-08-24T11:19:00.002+02:00

Map<String, String> map = new HashMap<String, String>();
     map.put("1", "abc");
     map.put("1", "def");
     Iterator it = map.entrySet().iterator();
     while (it.hasNext()){
      Map.Entry<String, String> pairs = (Map.Entry<String, String>)it.next();
      System.out.println(pairs.getKey() + "    " + pairs.getValue());
     }

RESULT:

1    def

My backup script in bash

2010-07-26T09:22:00.003+02:00

#! /bin/bash

_DEBUG="on"

TOMBOY="/media/ext500hdd/Backups/Ubuntu-9.04/tomboy"
PIDGIN="/media/ext500hdd/Backups/Ubuntu-9.04/purple"
BANKING="/media/ext500hdd/Backups/Ubuntu-9.04/banking"
CPP="/media/ext500hdd/Backups/Ubuntu-9.04/CPP"
DOCS="/media/ext500hdd/Backups/Ubuntu-9.04/docs"
PICS="/media/ext500hdd/Backups/Ubuntu-9.04/pics"
QT="/media/ext500hdd/Backups/Ubuntu-9.04/Qt"
WORKSPACE="/media/ext500hdd/Backups/Ubuntu-9.04/workspace"
XCHAT="/media/ext500hdd/Backups/Ubuntu-9.04/xchat"
JAVATOOLS="/media/ext500hdd/Backups/Ubuntu-9.04/javaTools"

export BACKUPS="$HOME/.tomboy:$TOMBOY \
$HOME/.purple:$PIDGIN \
$HOME/Banking:$BANKING \
$HOME/C++:$CPP \
$HOME/Documents:$DOCS \
$HOME/Pictures:$PICS \
$HOME/Qt:$QT \
$HOME/workspace:$WORKSPACE \
$HOME/.xchat2:$XCHAT \
$HOME/Java-tools:$JAVATOOLS \
"

function backup_dir () {
mkdir -p $2
rsync -r $1 $2
}

for X in $BACKUPS; do
SOURCE="`echo $X | cut -d : -f 1 `"
DEST="`echo $X | cut -d : -f 2 `"
backup_dir $SOURCE $DEST
done

A functioning Java gmail email sender (use the latest javamail jar)

2010-07-26T09:10:00.003+02:00

import java.security.Security;
import java.util.Properties;
import javax.mail.Message;
import javax.mail.MessagingException;
import javax.mail.PasswordAuthentication;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeMessage;

public class Assimilator {

 private static final String SMTP_HOST_NAME = "smtp.gmail.com";
 private static final String SMTP_PORT = "465";
 private static final String emailMsgTxt = "You will be assimilated";
 private static final String emailSubjectTxt = "A message from the borg";
 private static final String emailFromAddress = "god@microsoft.com";
 private static final String SSL_FACTORY = "javax.net.ssl.SSLSocketFactory";
 private static final String[] sendTo = { "xxxx" };

 public static void main(String args[]) throws Exception {
  Security.addProvider(new com.sun.net.ssl.internal.ssl.Provider());
  new Assimilator().sendSSLMessage(sendTo, emailSubjectTxt, emailMsgTxt,
    emailFromAddress);
  System.out.println("Sucessfully Sent mail to All Users");
 }

 public void sendSSLMessage(String recipients[], String subject,
   String message, String from) throws MessagingException {
  boolean debug = true;

  Properties props = new Properties();
  props.put("mail.smtp.host", SMTP_HOST_NAME);
  props.put("mail.smtp.auth", "true");
  props.put("mail.debug", "true");
  props.put("mail.smtp.port", SMTP_PORT);
  props.put("mail.smtp.socketFactory.port", SMTP_PORT);
  props.put("mail.smtp.socketFactory.class", SSL_FACTORY);
  props.put("mail.smtp.socketFactory.fallback", "false");

  Session session = Session.getDefaultInstance(props,
    new javax.mail.Authenticator() {
     protected PasswordAuthentication getPasswordAuthentication() {
      return new PasswordAuthentication("xxx@xxx.xxx", "xxx");
     }
    });

  session.setDebug(debug);

  Message msg = new MimeMessage(session);
  InternetAddress addressFrom = new InternetAddress(from);
  msg.setFrom(addressFrom);

  InternetAddress[] addressTo = new InternetAddress[recipients.length];
  for (int i = 0; i < recipients.length; i++) {
   addressTo[i] = new InternetAddress(recipients[i]);
  }
  msg.setRecipients(Message.RecipientType.TO, addressTo);

  // Setting the Subject and Content Type
  msg.setSubject(subject);
  msg.setContent(message, "text/plain");
  Transport.send(msg);
 }
}

A quick pdf using iText and Java

2010-07-26T09:08:00.001+02:00

void makePDF() {
  File f = new File(pdf);
  f.delete();
  Rectangle pageSize = new Rectangle(400, 400);
  pageSize.setBackgroundColor(new java.awt.Color(0x77, 0x00, 0xff));
  Document document = new Document(pageSize);
  try {
   PdfWriter.getInstance(document, new FileOutputStream(pdf));
   document.open();
   Chunk myLogo = new Chunk(Image.getInstance(logo), 0, -45);
   Paragraph p = new Paragraph(myLogo);
   p.setAlignment(Image.MIDDLE);
   p.add(" The big deal site");
   document.add(new Paragraph("\n\n"));
   document.add(p);
   document.add(new Paragraph("\n\n\n\n"));
   document.add(new Paragraph("Dear ${name_here}"));
   document.add(new Paragraph("Thank you for buying this ticket: "
     + "0320090001"));
   document.add(new Paragraph("\n"));
   document.add(new Paragraph(
     "The draw ends on ${date} and the prize will be notified on ${date+182 days}"
       + " (the reason for the delay is to prevent credit card fraud.)"));
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (DocumentException e) {
   e.printStackTrace();
  } catch (MalformedURLException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  }
  document.close();

how to create a Java class object from a file

2010-07-24T08:57:00.003+02:00

public static Class createClassFromBytes(String fileName) {
  Class clazz = null;
  File file = new File(fileName);
  try {
   byte[] ba = getBytesFromFile(file);
   // FileVisitor extends ClassLoader
   clazz = new FileVisitor().defineClass(null, ba, 0,

   (int) file.length());
  } catch (IOException e) {
   e.printStackTrace();
  }
  return clazz;
 }

 public static byte[] getBytesFromFile(File file) throws IOException {
   InputStream is = null;
   try {
    is = new FileInputStream(file);
   } catch (FileNotFoundException e) {
    e.printStackTrace();
   }
   byte[] bytes = new byte[(int) file.length()];
   // Read in the bytes
   int offset = 0;
   int numRead = 0;
   try {
    while (offset bytes.length (numRead = is.read(bytes, offset, bytes.length - offset)) = 0) {
     offset += numRead;
    }
   } catch (IOException e) {
    e.printStackTrace();
   }
   // Ensure all the bytes have been read in
   if (offset &lt; bytes.length) {
    throw new IOException("Could not completely read file "
      + file.getName());
   }
   // Close the input stream and return bytes
   is.close();
   return bytes;
  }

syntax highlighted by Code2HTML, v. 0.9.1

A database query using tomcat & servlets & JNDI

2010-07-24T00:32:00.003+02:00

controller: PersonRead.java

package web;

import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.sql.DataSource;

import org.apache.log4j.Level;
import org.apache.log4j.Logger;

public class PersonRead extends HttpServlet {
 private static final long serialVersionUID = 1L;
 final Logger logger = Logger.getLogger(PersonRead.class.getName());
 ArrayList<String> colList = null;
 private DataSource dataSource;
 private Connection connection;
 
 public void init( ) throws ServletException {
  try {
   Context initContext = new InitialContext();
   Context envContext = (Context) initContext.lookup("java:/comp/env");
   dataSource = (DataSource) envContext.lookup("jdbc/mysql");
  } catch (NamingException e) {
   e.printStackTrace();
  }
 }

 void connect() {
  String url = "jdbc:mysql://localhost:3306/person";
  String user = "root";
  String pass = "root";
  try {
   Class.forName("com.mysql.jdbc.Driver");
   connection = (Connection) DriverManager.getConnection(url, user, pass);
   logger.log(Level.INFO, "Connection successful");
  } catch (SQLException e) {
   e.printStackTrace();
  } catch (ClassNotFoundException e) {
   e.printStackTrace();
  } catch (SecurityException e) {
   e.printStackTrace();
  } 
 }

 ArrayList<Person> getPerson() {
  ArrayList<Person> pList = new ArrayList<Person>();
  PreparedStatement preparedStatement = null;
  ResultSet resultSet = null;
  try {
   connection = dataSource.getConnection();
   preparedStatement = connection
     .prepareStatement("select * from person order by id");
   resultSet = preparedStatement.executeQuery();
   java.sql.ResultSetMetaData rsm = resultSet.getMetaData( );
   int colCount =  rsm.getColumnCount( );
   colList = new ArrayList<String>();
   for (int i = 1; i <= colCount; i++) {
    colList.add(rsm.getColumnName(i));
   }

   while (resultSet.next()) {
    Person p = new Person();
    p.setName(resultSet.getString("name"));
    p.setSurname(resultSet.getString("surname"));
    p.setIdNumber(resultSet.getInt("id"));
    pList.add(p);
   }
  } catch (SQLException e) {
   e.printStackTrace();
  } finally {
   if (preparedStatement != null)
    try {
     preparedStatement.close();
    } catch (SQLException e) {
     e.printStackTrace();
    }
   if (resultSet != null)
    try {
     resultSet.close();
    } catch (SQLException e) {
     e.printStackTrace();
    }
   if (connection != null)
    try {
     connection.close();
    } catch (SQLException e) {
     e.printStackTrace();
    }
  }
  return pList;
 }

 public void doGet(HttpServletRequest request, HttpServletResponse response)
 throws IOException, ServletException {
  doPost(request, response);
 }
 
 public void doPost(HttpServletRequest request, HttpServletResponse response)
   throws IOException, ServletException {
  ArrayList<Person> personList = getPerson();
  request.setAttribute("data", personList);
  request.setAttribute("columns", colList);
  RequestDispatcher view = request.getRequestDispatcher("resultDB.jsp");
  view.forward(request, response);
  
  
 }
}

syntax highlighted by Code2HTML, v. 0.9.1
context: context.xml

   type="javax.sql.DataSource" username="root" password="root"
   driverClassName="com.mysql.jdbc.Driver"
   url="jdbc:mysql://localhost:3306/person"
   maxActive="10" maxIdle="4" />

neat tool to format code to post into my blog

2010-07-24T00:14:00.003+02:00

http://www.palfrader.org/code2html/code2html.html

Struts2 snippets

2009-09-25T12:26:00.004+02:00

Make sure the project compiles to:

~/WebContent/WEB-INF/classes

Check the project's context root (Eclipse) by going to

properties -> web project settings

JSP's and Tomcat JNDI with Eclipse

2009-09-23T15:43:00.004+02:00

To run the mysql jar, manually copy it into ~/lib folder. This will prevent hair loss! Create a context.xml file in META-INF. I've modified the controller to use Tomcat JNDI. See code page.

JSP's

2009-09-23T13:07:00.002+02:00

Doing some database read/writes. Check the code page for implementations. Interesting fact: A servlet is a singleton. This means that one can't use instance variables, because everyone who hits the server will be sharing those variables. This was reflected in my code. Note where I wanted to pass through the column headers: I had to use an instance variable.

IIS and ASP

2009-09-09T14:47:00.003+02:00

A pal asks me to fix the emailer on his site. I get an ftp login and am told "email is broken. Fix!". I didn't even know it was IIS until i jimmied a 404 error. IIS spilled her guts :) From there it was simple to find an IIS specific email script on thar interwebs. Plugged it in and jimmied the html and javascript. Presto :)

Eclipse

2009-08-24T09:37:00.003+02:00

To add the source to a jar you're using: properties -> java source attachment / javadoc attachment. Select the location of the src.jar and win. To add the source of the jvm you're using: window -> preferences -> java -> installed JREs. Select the JRE and edit the properties.

A custom Java environment

2009-07-21T16:27:00.009+02:00

So one day you decide you want a custom Java env. Well, make sure that you uninstall all the repo java files (you can probably do this in a better way. i.e. by keeping your repo java). Then insert something like:
in /etc/profile:

JAVA_HOME=/usr/lib/jvm/jdk1.5.0_15 export JAVA_HOME PATH=$PATH:$JAVA_HOME/bin export PATH

in .bashrc:

export ANT_HOME=/home/rick/ant #export JAVA_HOME=/usr/lib/jvm/jdk1.6.0_05 #export JAVA_HOME=/usr/lib/jvm/java-6-sun-1.6.0.16 export JAVA_HOME=/usr/lib/jvm/jdk1.5.0_15 #export JAVA_HOME=/usr/lib/jvm/j2sdk1.4.2_17 export ANT_OPTS="-Xmx2048m -Xms2048m" export JBOSS_HOME=/home/rick/jboss export JBOSS_CONFIG=stiffler export JBOSS_DEBUG_MODE=true export MAVEN_HOME=/home/rick/maven-1.0.2 export MAVEN_REPOSITORY=/home/rick/.maven/repository export MAVEN_REPO=/home/rick/.maven/repository export SCRIPTELLA_DIR=home/rick/Downloads/scriptella-1.0rc export PATH=$PATH:$SCRIPTELLA_DIR/bin export PATH=$PATH:$ANT_HOME/bin:$MAVEN_HOME/bin export PATH=$PATH:$JAVA_HOME/bin

Sed and Awk one liners

2009-07-21T09:03:00.005+02:00

http://sed.sourceforge.net/sed1line.txt

http://www.pement.org/awk/awk1line.txt

Java messaging

2009-05-07T13:40:00.007+02:00

I implemented a simple "Hello World!" style asynchronous messaging on Glassfish. First I wrote a message producer in a dynamic web project and added an arbitrary serializeable class. Then I created a message consumer in a separate EJB project. The consumer is a message driven bean. I posted the code on my code pages: http://rick.softly.googlepages.com/codepage

Setting up linker paths in linux

2009-03-31T10:53:00.003+02:00

to set global vars in *nix (.bashrc):

export LD_LIBRARY_PATH=/your/Dir/Here

This works in the bash environment only to get it to work in QDevelop IDE add

LD_LIBRARY_PATH=/your/Dir/Here under debug -> parameters -> environment variables

Now your programs can access the shared object files through the IDE

A ReSTful experience

2009-01-28T09:33:00.003+02:00

It took a little while but I've gone from never having heard of ReSTful web services to implementing a client. There are a few technologies out there that implement the services and clients, namely Jersey, Axis2. I settled on jdom. Jdom makes life very easy when dealing with xml. Jdom is a toolkit for xerces xml api. It had no problem extracting the xml in the form of an SAX document. It is able to effortlessly extract all the child elements into a list. The trick was to find out the format required for the outgoing SAX document. This was achieved by downloading the xml string from the ReST server. I parsed that file into a SAX document and PUT it to the server. Success. From there it was a case of stripping away the excess xml to find the minimal xml needed to create a SAX document that PUTs to the server. Once I had the format it was trivial to bypass the file by adding the changed data to a string and to parse the string into a SAX document ready for PUTting. The code: http://rick.softly.googlepages.com/ReSt.java.txt

my ant farm

2008-10-07T11:39:00.003+02:00

Wrote 2 ANT scripts. One is for the developers to branch and tag code across n amount of projects. The other is for the testers. They set my ant loose and in its anger it fetches code, compiles it, creates war files then an ear file. Ant then cleans everything up and the person is left with one (1) deployable ear file. The ear was tricky as ant doesn't explicitly support Glassfish, but I came right by using ANT Jar. Am thinking about hot deploying by merely ftp-ing to the test server and putting the ear file in the auto-deploy dir.

another week

2008-08-17T19:42:00.005+02:00

Spent some time configuring the office: wireless routers, wireless nic (netgear, it's crap - drops connections - back on cat5), samsung laser printer. KES is going forward: I'm integrating the reports using Travis' jasper/iReports framework. Basically, looking up the parameters needed via iReports parameters and SQL files, hunting those params in the DB, coding the seeks using dal objects and then passing the results to jasper to make reports. I want to knock these reports out of the way and start reading more on ANT. I'm getting tired of doing the daily backups by hand and emailing the results.

My ferret

2008-07-31T08:05:00.004+02:00

I had a need to search my code base for strings this week. A mate of mine, Ilan Pillemer, gave me a ferret to search with. He also gave me an interest to learn AWK.

du -a | grep .java | mawk '{print $2}' | xargs mawk ' /Insert string here/ {printf "File Name: %s\n Line Number: %s \n\%s[B\n",FILENAME,FNR,$0}'

Setting up Trac

2008-07-18T08:33:00.013+02:00

After scrawling 263 lines of java code in Eclipse on Monday, I was left with not much to do. I was tasked to setup a code repository on our web server. After hunting about on google and asking friends, I settled on using subversion (SVN). Trac has a nice web face for it. After wising up on apache and subversion, I have SVN configured to eclipse. Trac is a fantastic online repo browser and ticket manager. I have configured it on our company's web server to work with our repo :) Some important links and tips that I used are:
SVN: http://www.howtogeek.com/howto/ubuntu/install-subversion-with-web-access-on-ubuntu/
SVN connector for ganymede: http://blog.punchbarrel.com/2008/06/30/using-the-new-subversion-integration-in-eclipse-ganymede/
How to check modules loaded in apache: httpd -M (linux) apache2ctl -M (ubuntu)

httpd.conf is replaced by apache2.conf in Ubuntu
Use wget to copy files from the web through ssh console Vi manual: http://www.cs.fsu.edu/general/vimanual.html#input

SVN manual: http://svnbook.red-bean.com/

The permissions you need to set are on the /var/www/.python-eggs directory.
Make sure it exists first by running: mkdir -p /var/www/.python-eggs then chown -R www-data:www-data /var/www/.python-eggs to allow apache to write to it.
Apache and python: https://coderanger.net/~coderanger/tracdoc/install/mod_python.html#apache Changes made to apache2.conf:

#adding svn location entries - Rick 16 July 2008 < Location /svn> DAV svn SVNParentPath /svn SVNListParentPath on AuthType Basic AuthName "My subversion repository" AuthUserFile /etc/apache2/dav_svn.passwd Require valid-user </Location> < Location /trac> SetHandler mod_python PythonInterpreter main PythonHandler trac.web.modpython_frontend PythonOption TracEnv /trac PythonOption TracUriRoot /trac SetEnv PYTHON_EGG_CACHE /var/www/.python-eggs </Location> < Location /trac/login> AuthType Basic AuthName "ProjectName" AuthUserFile /etc/apache2/dav_svn.passwd Require valid-user </Location>

Job

2008-07-13T08:55:00.000+02:00

Work this last month on the POS system was interesting. I was fleshing out old classes and creating new classes from the abstract DAL class. I was updating panels using our wizard class. I was using mySQL to add fuctionality to the DAL's, ie creating and updating staff records, vehicle records etc.

Snoopy, the new puppy

2008-01-29T12:48:00.000+02:00