Sunday, April 21, 2013

Install MongoDB as windows service

We can also configure MongoDB to run as a windows service .  
mongod.exe added support for running as a Windows service in version 2.0, and mongos.exe added support for running as a Windows Service in version 2.1.1.

Step 1 : Create configuration file mongod.cfg .

echo logpath=C:\mongodb\log\mongo.log > C:\mongodb\mongod.cfg

A new file mongod.cfg will be created at location C:\mongodb. This file contains an entry logpath which tells mongodb to save all logging information in the specified file mongo.log

Step 2 :  Install MongoDB as a service .
Execute following command in command prompt :

mongod --config C:\mongodb\mongod.cfg --install

A new windows service will be created .

Step 3 : Start Mongo Service 
Execute following command in command prompt :

net start MongoDB

Other Options :

1 . Stopping MongoDB Service :
     net stop MongoDB

2 . Removing MongoDb service :
     mongod.exe --remove

Thursday, April 18, 2013

How to delete a tag in Github.

Following commands can be used to delete a tag in git.

1. Delete tag from local
     git tag -d [tag];

2. Push changes to remote
     git push origin :[tag]

Example :
Let say you have created a tag by name v6.37.1 . Now to delete the tag from git :

1.  git tag -d v6.37.1

2.  git push origin :v6.37.1

If your tag has the same name as one of your branches then ,

1. git tag -d [tag]

2. git push origin :refs/tags/[tag]

MongoDB installation on Windows

1. Download MongoDB .

2. Extract the downloaded zip to a directory say, 

3. set path  ( C:\mongodb-win32-x86_64-2.4.2\bin ) in environment variable ( Optional )
4. Mongo requires a data directory to store its files . Default location is  C:\data\db.  Create these  folders.
5. Start MongoDB in command prompt. mongod.exe is present in the bin directory of the distribution.

6.Connect to MongoDb using  Mongo shell in a new command prompt.

Now you can insert data in mongo db . Below is an example .

Wednesday, April 17, 2013

How to configure/integrate Weblogic8.1 in MyEclipse 5.5.1 GA

Integrating weblogic in MyEclipse is quite easy but before beginning you should be familiar with Weblogic
Server concepts and installation location details.

Properties :-

1)BEA Home Directory Path to BEA home directory. WebLogic consults this directory for its license and registry files. eg. C:\bea (considering that weblogic is installed in C:\ directory)

2)Weblogic installation directory Path to WebLogic Server installation directory. (eg. C:\bea\weblogic81)

3)Administration Username The name of the WebLogic system admin user.

4)AdministrationPassword The password of the WebLogic system admin user.

5)Execution Domain Root Directory that contains the execution domain directory.( eg. C:\bea\user_projects\mydomain)

6)Execution Domain Name The name of the WebLogic domain to execute under the root directory.( e.g. mydomain)

7)Execution Server Name The name of the WebLogic server that runs the domain. The server name is specified within the domain’s config.xml file. (eg. myserver)

8)Hostname:Number The hostname: portnumber of WebLogic server instance.(eg. localhost:7001)

9)Security Policy File The location of the security file used by WebLogic(eg. C:\bea\weblogic81\server\lib\weblogic.policy)

10)JAAS Login Configuration File This is not compulsary parameter It is required when the login configuration path is not specified in the security policy file or the user’s home directory for WLS 6.x.

Steps to integrate webogic8.1 :-1. Begin by clicking on the icon in the MyEclipse toolbar for configuring servers

2. Select the option "configure server"

3. select Application Servers -> Weblogic -> Weblogic 8.x

4. Fill all the required parameters as specified below. The parameters in this example are filled by considering that the weblogic server is installed in C:\ directory i.e the BEA Home directory is C:\bea

Steps to Configure JDK properties:-
The picture below defines the Java JDK preferences for an application server connector. The connector will use these parameters to determine the Java Virtual Machine and commandline arguments in the launch phase of an application server connector's life-cycle.

NOTE: The JDK Name value must identify a full Java JDK install. Do not specify a JRE. Doing so will result in launch failures of your server connector.

Steps to configure Launch properties:-Launch Mode defines if the mode in which the server connector will launch an instance. Debug mode enables uses of Eclipse/MyEclipse Java and JSP debugging capabilities such as breakpoints, inspectors, and hot-swap code changes. Run mode disables use of debugging features but offers better performance.

Steps for Configuring Paths:-There are three parameters to be provided and none of them is compulsary so you can leave them blank.

a)Prepend to classpath:-
Browse to and select the JAR and ZIP archives and the class directories you wish to have added to the beginning of the server connector JVM's classpath. Additions will be loaded by the Java VM before the web-server core classes.

b)Append to classpath:-
Browse to and select the JAR and ZIP archives and the class directories you wish to have added to the end of the server connector JVM's classpath. Additions will be loaded by the Java VM after the web-server core classes.

c)Append to library path:-
Browse to and select the platform-specific native libraries to be appended to the java.library.path.

So all the required configuration is done. Now just start the server and deploy your projects.

Done !!!

How to insert an image in Oracle through Servlet

Hi all,

In this post i will tell you how to insert image in a database (Oracle) through a Servlet.

First of all make a table in Oracle named "image_master" having three fields i.e id, name, image.

Step 1:- Creating table in database.
just copy / paste the code in oracle SQL command line:-
 "NAME" VARCHAR2(40), 

Step 2:- Create a Servlet for inserting image.
Now after creating the table, make a servlet named "InsertImage" which extends HttpServlet and overrides doGet() and doPost() method.

package others;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class InsertImage extends HttpServlet {
    private static final long serialVersionUID = 1L;

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        try {
             * make a database connection. Here we are making connection with oracle database.
             * for Oracle Type-4 driver:-
             * Driver Class = ("oracle.jdbc.driver.OracleDriver")
             * Connection String = ("jdbc:oracle:thin:@localhost:1521:xe","user_name","password")
            Connection con = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:xe", "system", "oralce");
             * making an object of FileInputStream for reading the image file in form of bytes.
             * path of the file is provided as an argument.
            FileInputStream fis = new FileInputStream("c:/images/hello.jpg");
            PreparedStatement st = con.prepareStatement("insert into image_master values(?,?,?)");
            st.setInt(1, 1001);
            st.setString(2, "Prakash");
             * method setBinaryStream() is used for inserting image in database.
            st.setBinaryStream(3, fis, fis.available());
        } catch (Exception e) {

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doGet(request, response);

Step 3:- Making web.xml entry:-

MongoDB introduction

MongoDB is a Non Relational JSON document store/database . Non relational means it does not supports relational algebra between the tables like SQL ( Does not support JOINs).

Benefits :

  • High performance.
  • High availability.
  • Highly  scalable.

MongoDB does not supports JOINs :
Joins scales poorly when we try to scale out to multiple nodes. 

No transaction support :
MongoDB doesn't provide any transaction support. Something that requires multiple updates within a relational system can be handled within a single atomic transaction within a single document in mongo.