Valeosys

A Javanese Java Programmer sipping a daily cup of Java in the island of Java.

[valeosys]

Reading an XML from a file system path

XML file can be manipulated when converted to the Document class. To read an XML file from a path on the file system and convert it to the Document class, we can use the DocumentBuilderFactory.

An example method is shown below:

public Document readXml(String absolutePath) throws ParserConfigurationException, SAXException, IOException { DocumentBuilderFactory dbf=DocumentBuilderFactory.newInstance();      DocumentBuilder db =dbf.newDocumentBuilder();      return (Document) db.parse(absolutePath); }

[valeosys]

Render PDF as image in Java

Under a java swing desktop application, rendering PDF as an image can be done by using the PDFRenderer library. The current release which I was using was PDFRenderer-0.9.1.jar

Below is a sample from one of my applications to render the PDF on a JLabel.

private void renderPdfAsImage(File file) throws FileNotFoundException, IOException { //load a pdf from a byte buffer RandomAccessFile raf = new RandomAccessFile(file, "r"); FileChannel channel = raf.getChannel(); ByteBuffer buf = channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size()); PDFFile pdffile = new PDFFile(buf); // draw the first page to an image PDFPage page = pdffile.getPage(0); //get the width and height for the doc at the default zoom Rectangle rect = new Rectangle(0,0, (int)page.getBBox().getWidth(), (int)page.getBBox().getHeight()); //generate the image Image img = page.getImage( rect.width, rect.height, //width & height rect, // clip rect null, // null for the ImageObserver true, // fill background with white true // block until drawing is done ); outputLabel.setIcon(new ImageIcon(img)); this.setVisible(true); }

[valeosys]

Render an Image in Java

Rendering an image taken from a file to your Java Swing application can be done as simple as using an ImageIcon Class and applying it on a JLabel.

Here is a sample method taken from one of my applications:

private void renderImage(File file) {         ImageIcon gbr = new ImageIcon(file.getAbsolutePath());         outputLabel.setIcon(gbr);         this.setVisible(true);     }

[valeosys]

T24 Tools and Utilities

Below are a few tools and utilities available for maintaining T24.

BASIC LISTING BASIC.LISTING should be run during an occurrence of COB/EOD problem to extract system information, which will help CSHD to assess the nature of the crash and helps in locating the problematic area to be focussed for further analysis. CHECK.T24.FILES This utility would help in identifying improperly sized and corrupted jBASE files. To resize the files in jBASE, a document is provided in addition with the tool. DATA DIAGNOSTIC TOOL DATA DIAGNOSTIC is a multi-threaded tool which is used to extract the listing from a huge size database/file. It reduces the time taken to extract the listing. HD.COMO.VIEWER This utility will help in extracting COMO pertaining to a job, from all agents/sessions run during COB/EOD or a service. JOB TIME ANALYSER This utility helps in collecting information on Start time, End time, Elapsed time, Processed records, Throughput, Selection time etc., for every COB job. This will help in understanding and fine tuning the performance of every job. REPORT TIME ANALYSER This utility helps in collecting information of time taken by each job/report, which can be used as input for understanding and fine tuning the performance of every report and its job. EB.PRINT.RECORD This utility helps in data extraction – snapshots of contracts, system records, jbase command output. Check Record Size This utility is useful for jBASE database site. It reports in Bytes on the screen and while storing it writes in KB. This will generate output that will give the record size in KB. Based on the information the block size to be used for Striping the disks can be recommended to the client IT team.

[valeosys]

JBase Editor tips & tricks

Quit Editor after multiple select

After a SELECT + EDIT / jed, to quit the editor: Escape !EXK + Return Escape EXK + Return

When editing a record: insert VM & SM separator

Place the cursor between the two values and strike: Ctrl ]         Insert ]  value mark       Ctrl \         Insert \ subvalue mark

Other useful commands

Globus>JED File Id  Edit record BI = Equivalent to the Universe ‘FORMAT’ 0001 Esc            Go to Command-> 0001 Ctrl X         Exit 0001 Ctrl A         Move to start of current line 0001 Ctrl E         Move to end of current line 0001 Ctrl W         Delete word 0001 Ctrl K         Clear to end of line. 0001 Ctrl DD        Delete current line 0001 Ctrl G         Mark block. 0001 Ctrl L         Insert line below current line 0001 Ctrl N         Locate next occurrence 0001 Ctrl O         Toggle overwrite and insert. 0001 Ctrl T         Mirror character above 0001 Ctrl V         Indent for BASIC 0001 Ctrl ]         Insert ]  value mark 0001 Ctrl \         Insert \ subvalue mark

Command->ex         Exit Command->exk        Exit key. Do not load list items Command->FI         Save and exit Command->FS         Save Command->FD         Delete record Command->nn         Go to line nn Command->L string   Locate “string” Command->/string    Locate “string string” Command->CAn        Copy Marked block after current line, n times Command->CBn        Copy Marked block before current line, n times Command->MAn        Move Marked block after current line, n times Command->MBn        Move Marked block after current line, n times Command->DEn        Delete line after current line. n times Command->R/a/b/n    Change a to b on current line. n times Command->RU/a/b     Change all a to b on current line. Command->R9/a/b     Change a to b on 9 lines from current. Command->BI         Format BASIC code Command->BION       Turn on Format indentation Command->S?         Display record size Command->! Cmd      Execute command Command->!!         Re-execute last ! Cmd Command->HEX        Toggle the display in Hexadecimal  

jsh command

Globus>ls           Execute unix cmd excluded pipe, redirection, wildcards characters Globus>env          Display environment setting unix Globus>Row up       Command stack  Get previous command Globus>Ctrl e       Command stack  Move to end of line Globus>Ctrl a       Command stack  Move to beginning of line Globus>ESEARCH      Search string in records

jsh command for administration

Globus>jdiag           Display environment setting jbase Globus>jshow           Show catalog Globus>jstat -?        Analyse file sizing Globus>jrf -?          Resize file Globus>where (V        Display process details Globus>show-item-locks Display locks Globus>logoff Portno   Logoff user

[valeosys]

Multithreaded Compression

I've recently came across a situation where when compressing large files takes a while and turns out it only uses a single thread.

To optimize this I used pigz, a parallel implementation of gzip.

To install on ubuntu:

sudo apt-get install pigz

To compress in combination using tar, execute the following commands:

tar cvf - [paths-to-archive] | pigz > archive.tar.gz

By default pigz uses 8 cores and a variable factor of 6 for compression, simmilar to gzip you may request a better compression using -9. You can also increase the amount of processor to use with -p n. Also to increase speed, you might also leave out -v.

tar cf - [paths-to-archive] | pigz -9 -p 32 > archive.tar.gz

[valeosys]

Virtual Serial Ports on Ubuntu 12.10

I've been recently working on a Java application that reads raw data from a serial port. To create a virtual port and link each other I used socat, its lightweight, efficient and powerful.

sudo apt-get install socat

To create a link between the two ports:

socat -d -d PTY PTY

There are some extra parameters that you might want to use for your specific needs. As for me, the library that I used only looked for ports with predefined prefixes such as ttyUSB, ttyS, rfcomm etc.

By default socat creates the port under /dev/pts/[some number]. So I had to create links that was readable by the library. To do that I did the following:

socat -d -d PTY,link=/dev/ttyS10 PTY,link=/dev/ttyS11

And there you have it, a working serial port link on a loop.

[valeosys]

Virtual Box Installation on Ubuntu 12.10

Open a terminal window and type the following:

sudo sh -c "echo 'deb http://download.virtualbox.org/virtualbox/debian '$(lsb_release -cs)' contrib non-free' > /etc/apt/sources.list.d/virtualbox.list" && wget -q http://download.virtualbox.org/virtualbox/debian/oracle_vbox.asc -O- | sudo apt-key add - && sudo apt-get update && sudo apt-get install virtualbox-4.2 dkms

When I installed the current version is 4.2, so replace the version number if they have future releases.

Basically what it does is:

Add the repository in the sources list

Download and register the Oracle Public Key

Update sources and install the virtual box

https://www.virtualbox.org/wiki/Linux_Downloads

[valeosys]

Shrinking Windows NTFS and Create a Linux Partition

Most laptop distribution comes with a predefined HD partition. If we choose to install our linux distribution early we're in luck. This is not the case if we've had our data stored in it.

A standard ubuntu 12.10 installation should only require around 25 GB of free space. After freeing up some free space to allocate for a linux installation, I tried shrinking the main NTFS partition in C:\

To do this, go to:

Control Panel > System Maintenance > Administrative Tools > Computer Management Storage > Disk Management

Right click on the desired partition and choose shrink. It should give you some free space to shrink. If you happen to have more free space than the allowed size, this is probably because you have some system files or data files located near the rear sector of this drive.

As for my case, I had only 5 GB of free space allowed to shrink. To allow more free space for shrinking, I suggest the following:

Check HD for errors

Disable / relocate windows page file

Disable File Indexing Services

Disable Hibernation

Defragment using windows default tools

Defragment using third party software:

Auslogics Disk Defrag (Free)

Perfect Disk (Trial)

Perfect Disk has a utility for SMART Placement as well as Shrink Preparation.

Once all the files are moved up near the front sector of the drive, we're good to go. The downside of defragmenting and optimizing under windows is that there are metadatas that are stored in some sectors of the drive which aren't movable. To move this, a more aggressive behaviour of boot time defragmenting may be required.

After freeing up some unallocated partition space, the next step is to create a linux partition and install.

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Automount NTFS file system on Ubuntu 12.10

Ubuntu 12.10 has the ability to “auto mount” your NTFS file systems if you happen to dual boot. Unfortunately, to do this you must first open nautilus and click on the corresponding drives respectively.

An easy way to mount those file system permanently at startup is to install NTFS Configuration Tool.

Press Ctrl+Alt+T to open a terminal window and type the following commands:

sudo apt-get install ntfs-config

Once installed type the following command:

sudo mkdir -p /etc/hal/fdi/policy

To run the application type:

sudo ntfs-config

After opened, under Advanced Configuration make sure to set the mounting point under the directory /media

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[valeosys]

Why investors seek these words from entrepreneurs

Shit Entrepreneurs Say http://allthingsd.com/20120820/shit-entrepreneurs-say/