Accessing MS Access using JDBC

Since Microsoft does not provide 64 bit drivers for Access; it becomes a nuisance to access MS Access under 64 bit platforms.

For a successfull connection to MS Access DB File (*.mdb) with JDBC under 64 bit platforms, follow following steps:

1- Make sure Access drivers are installed. If access is installed it is already there, else download from this link and install.

2- Configure Data Source Name using 32 bit ODBC Data Source Administrator. Use the executable at c:\windows\sysWOW64\odbcad32.exe.

3- System DSN->Add->Microsoft Access Driver (*.mdb)

- Specify a Data Source Name

- Specify a description

- Locate mdb file.

- Click OK.

Picture 1 DSN Setup for MS Access

Picture 2 New DSN

4- Use code fragment below to obtain connection.

private static Connection getConnection() throws SQLException, ClassNotFoundException {

Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");

return DriverManager.getConnection("jdbc:odbc:SGECA");

}

5- Launch Java application using 32 bit JVM which can be found under:

C:\Program Files (x86)\Java\jre7

Comments

Obfuscating Spring Boot Projects Using Maven Proguard Plugin

Introduction Obfuscation is the act of reorganizing bytecode such that it becomes hard to decompile. Many developers rely on obfuscation to save their sensitive code from undesired eyes. Publishing jars without obfuscation may hinder competitiveness because rivals may take advantage of easily decompilable nature of java binaries. Objective Spring Boot applications make use of public interfaces, annotations which makes applications harder to obfuscate. Additionally, maven Spring Boot plugin creates a fat jar which contains all dependent jars. It is not viable to obfuscate the whole fat jar. Thus obfuscating Spring Boot applications is different than obfuscating regular java applications and requires a suitable strategy. Audience Those who use Spring Boot and Maven and wish to obfuscate their application using Proguard are the target audience for this article. Sample Application As the sample application, I will use elastic search synch application from my GitHub repository.

Hadoop Installation Document - Standalone Mode

This document shows my experience on following apache document titled “Hadoop:Setting up a Single Node Cluster”[1] which is for Hadoop version 3.0.0-Alpha2 [2]. A. Prepare the guest environment Install VirtualBox. Create a virtual 64 bit Linux machine. Name it “ubuntul_hadoop_master”. Give it 500MB memory. Create a VMDK disc which is dynamically allocated up to 30GB. In network settings in first tab you should see Adapter 1 enabled and attached to “NAT”. In second table enable adapter 2 and attach to “Host Only Adaptor”. First adapter is required for internet connection. Second one is required for letting outside connect to a guest service. In storage settings, attach a Linux iso file to IDE channel. Use any distribution you like. Because of small installation size, I choose minimal Ubuntu iso [1]. In package selection menu, I only left standard packages selected. Login to system. Setup JDK. $ sudo apt-get install openjdk-8-jdk Install ssh and pdsh, if not already i

Java: Cost of Volatile Variables

Introduction Use of volatile variables is common among Java developers as a way of implicit synchronization. JIT compilers may reorder program execution to increase performance. Java memory model[1] constraints reordering of volatile variables. Thus volatile variable access should has a cost which is different than a non-volatile variable access. This article will not discuss technical details on use of volatile variables. Performance impact of volatile variables is explored by using a test application. Objective Exploring volatile variable costs and comparing with alternative approaches. Audience This article is written for developers who seek to have a view about cost of volatile variables. Test Configuration Test application runs read and write actions on java variables. A non volatile primitive integer, a volatile primitive integer and an AtomicInteger is tested. Non-volatile primitive integer access is controlled with ReentrantLock and ReentrantReadWriteLock to compa

Huseyin ABANOZ

Search This Blog