Blogs by Ganesh Babu N R

Blogs by Ganesh Babu N R: Java DB Derby Example

2009-12-04T21:45:00.000-08:00

Blogs by Ganesh Babu N R: Java DB Derby Example

Java DB Derby Example

2009-12-04T21:43:00.000-08:00

There are tons of information on Java DB or Derby. However I found that there was not a single place that gave a complete example to use Derby to store and retrieve XML Data Type - Derby in Server Mode of Operation.

So I thought I would post the code that got me going successfully - for the benefit of someone else, provided Google gets to this posting!

Installation - Note Derby and Java DB are synonymous - almost!

Install Java DB 10.5.3.0.
Create a Database -
In the java.policy file found in ${Java_Home}\jdk1.6.0\jre\lib\security add the below shown grant{} block
In the startNetworkServer.bat file - set the derby.system.home property.
Start the Derby Engine by double clicking startNetworkServer.bat [in Windows]
You should not see any java.security.access Exception for Derby.Log file - else revisit step-3
See if Derby.Log file is created in the derby.system.home. If you don't find, then check the startNetworkServer.bat folder [nothing but the /bin folder] - if a Derby.Log file is found here, then Revisit Step-3. If you don't clear this step, later on, when you run the program you will see "Database Jeevi Not Found" exception. Because Derby will search for "Jeevi" folder in /bin folder.
Create a New Java Project in NetBeans 6.5.1 - you may use the below package structure and copy paste the code as-is
Add Derby.jar, DerbyNet.jar and DerbyClient.jar to the NetBeans Project Library
Compile and Run
See the Output

@@@@@ Java.Policy file entries @@@@@

//all below lines are added for Derby to work
//NOTE: this throws open java permissions to every program
//better to use grant codeBase{derby.jar} and grant codeBase{derbynet} to restrict the access //only to derby
//this is an exhaustive list - see http://db.apache.org/derby/manuals/index.html#docs_10.5

grant{
permission java.util.PropertyPermission "user.home", "read";
permission java.util.PropertyPermission "java.home", "read";
permission java.lang.RuntimePermission "createClassLoader";
permission java.util.PropertyPermission "derby.*", "read";
permission java.io.FilePermission "C:\Program Files\Sun\JavaDB\*", "read,write,delete";
permission java.lang.RuntimePermission "createClassLoader";
permission java.util.PropertyPermission "derby.*", "read";
// The next two properties are used to determine if the VM is 32 or 64 bit.
permission java.util.PropertyPermission "sun.arch.data.model", "read";
permission java.util.PropertyPermission "os.arch", "read";
permission java.util.PropertyPermission "user.dir", "read";
permission java.util.PropertyPermission "derby.storage.jvmInstanceId", "write";
permission java.io.FilePermission "C:\Program Files\Sun\JavaDB","read";
permission java.io.FilePermission "C:\Program Files\Sun\JavaDB\*", "read,write,delete";
permission java.io.FilePermission "<>", "read,write,delete";
permission java.net.SocketPermission "*", "accept";
};

@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Add this line just below ":runWithClasspath" line
set DERBY_OPTS=%DERBY_OPTS% -Dderby.system.home="C:\Program Files\Sun\JavaDB"

@@@@@@@@@@@@@@@@@@@@@@@@@@@@

code:
package jdb.main;

import jdb.dao.ProcessSqlRequest;

public class Main {
public static void main(String[] args) {
ProcessSqlRequest p = new ProcessSqlRequest();
p.storeXML(); //stores an XML into Java DB as XML Datatype
p.fetchXML(); //retrieves XML from Java DB
}
}

@@@@@@@@@@@@@@@@@@@@@@@@@@@@

package jdb.dao;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;

public class ProcessSqlRequest {
public void fetchXML() {
try {
Connection con = new DBCon1().getConnection();
Statement s = con.createStatement();
ResultSet rs = null;
if(con != null)
{
//rs = s.executeQuery("SELECT XMLSERIALIZE(DATA AS VARCHAR(3000)) FROM ARTICLE WHERE ID = 3");
rs = s.executeQuery("SELECT ID, XMLSERIALIZE(DATA AS VARCHAR(3000)) FROM ARTICLE");
System.out.println("Ahh.....done");
}
else
{
System.out.println("Huh ....Connection Object Null");
return;
}
while (rs.next()) {
int id = rs.getInt("ID");
String temp = rs.getString("2");
System.out.println("DATA is ::: " + id + " ::: " + temp);
}
s.close();
con.close();
} catch (Exception e) {
System.out.println("Exception in ProcessSqlRequest().fetchXML()" + e);
e.printStackTrace();
}
}

public void storeXML() {
try {
Connection con = new DBCon1().getConnection();
Statement s = con.createStatement();
if(con != null)
{
///int i = s.executeUpdate("insert into ARTICLE (ID,DATA) values (4, XMLPARSE(DOCUMENT CAST (‘Your XML' AS CLOB) PRESERVE WHITESPACE");
int i = s.executeUpdate("insert into ARTICLE (ID,DATA) values (8, XMLPARSE(DOCUMENT CAST ('Your XML' AS VARCHAR(3000)) PRESERVE WHITESPACE))");
System.out.println("Inserted " + i + "...Rows");
}
else
{
System.out.println("Huh ....Connection Object Null");
return;
}
s.close();
con.close();
} catch (Exception e) {
System.out.println("Exception in ProcessSqlRequest().storeXML()" + e);
e.printStackTrace();
}
}
}

@@@@@@@@@@@@@@@@@@@@@@@@@@@@

package jdb.dao;

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

public class DBCon1 {
//private static final String url = "jdbc:derby://localhost:1527/jeevi";
private static final String url = "jdbc:derby://127.0.0.1:1527/jeevi";

// Load Derby Network Client driver class.
// If you are running on JDK 6 or higher, you do not
// need to invoke Class.forName(). In that environment, the
// network client driver loads automatically.
public Connection getConnection() throws Exception {
Connection conn = null;
Class.forName("org.apache.derby.jdbc.ClientDriver");
conn = DriverManager.getConnection(url);
System.out.println("Sql Connection Successful");
return conn;
}
}
:code

@@@@@@@@@@@@@@@@@@@@@@@@@@@

The output in NetBeans Log Window should show this - if everything is working for you...

run:
Sql Connection Successful
Inserted 1...Rows
Sql Connection Successful
Ahh.....done
DATA is ::: 7 ::: Your XML
DATA is ::: 8 ::: Your XML

@@@@@@@@@@@@@@@@@@@@@@@@@@@@

I am using NetBeans 6.5.1 and Java DB 10.5.3.0 and the above worked successfully.

Usage note from http://db.apache.org/derby/docs/10.2/ref/rreffuncxmlserialize.html
Derby requires that a JAXP parser, such as Apache Xerces, and that Apache Xalan are listed in the Java classpath for the XML functions to work. If either the JAXP parser or Xalan is missing from the classpath, attempts to use the XMLSERIALIZE operator will result in an error

@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Thanks to all the tons of documentation on Java DB by Sun, Derby by Apache, Cloudscape by IBM. I referred all to arrive at the above successful program.

@@@@@@@@@@@@@@@@@@@@@@@@@@@@

I would be happy to see a simple comment - by you - if at all Google got you here.

@@@@@@@@@@@@@@@@@@@@@@@@@@@@

Happy Derbyyyying !

Ganesh Babu N R

Java: DB Connection

2009-04-22T08:41:00.000-07:00

How to Connect to DB?

import java.sql.Connection;

import java.sql.DriverManager;

/**

* This Class returns a Connection Object

public class GetDBConnection

{

public GetDBConnection(){} //constructor

public java.sql.Connection getConnection()

{

Connection conn = null;

try

{

Class.forName("oracle.jdbc.driver.OracleDriver").newInstance();

conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:XE", "ganesh", "ganesh");

System.out.println("Successfully Connected to DB");

} catch (Exception e)

{

System.out.println("Exception Caught while Connecting to DB " + e.getMessage());

e.printStackTrace();

}

return conn;

}

############

import GetDBConnection;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

//Use the Connection object and make a connection to the db

//to check the credentials

public class ValidateUser

{

public boolean checkUser(String name, String pswd)

{

Connection conn = null;

PreparedStatement ps = null;

ResultSet rs = null;

try

{

conn = new GetDBConnection().getConnection();

ps = conn.prepareStatement("select password from PraanaUsers where username = ?");

ps.setString(1, name);

System.out.println("Executing SQLQUERY");

rs = ps.executeQuery();

System.out.println("SUCCESSFULLY EXECUTED RS");

String temp = null;

while (rs.next())

{

temp = rs.getString(1);

}

if (pswd.equals(temp))

{

System.out.println("User Exists...Validation Successful");

return true;

} else

{

System.out.println("User Does Not Exist...Validation Failed");

return false;

}

} catch (Exception e)

{

e.printStackTrace();

} finally

{

try {

if (rs != null) {

rs.close();

}

if (ps != null) {

ps.close();

}

if (conn != null) {

conn.close();

}

} catch (Exception e) {

e.printStackTrace();

}

return false;

}

Ganesh Babu N R

Java: String Date Conversions

2009-04-22T08:32:00.001-07:00

Here are some simple functions to handle conversion of Strings to Date Format.

package gutils;

import java.sql.Date;

import java.sql.Timestamp;

import java.text.DateFormat;

import java.text.SimpleDateFormat;

/**

* @author nrganeshbabu

public class Main {

/**

* @param args the command line arguments

public static void main(String[] args) throws Exception

{

convertString2UtilDate("30/09/1999");

converString2SQLDate("30/09/1999");

convertString2SQLDateTimeStamp("30/12/2020 18:45:54.999");

}

private static java.util.Date convertString2UtilDate(String date) throws Exception

{

DateFormat df = new SimpleDateFormat("dd/MM/yyyy");

java.util.Date utilDate = df.parse(date);

System.out.println(utilDate);

return utilDate;

}

private static java.sql.Date converString2SQLDate(String date) throws Exception

{

DateFormat df = new SimpleDateFormat("dd/MM/yyyy");

java.util.Date utilDate = df.parse(date);

java.sql.Date sqlDate = new Date(utilDate.getTime());

System.out.println(sqlDate);

return sqlDate;

}

private static java.sql.Timestamp convertString2SQLDateTimeStamp(String timestamp) throws Exception

{

SimpleDateFormat df = new SimpleDateFormat("dd/MM/yyyy hh:mm:ss.SSS");

java.util.Date utilDate = df.parse(timestamp);//yyyy-mm-dd hh:mm:ss.fffffffff

java.sql.Timestamp sqlTS = new Timestamp(utilDate.getTime());

System.out.println("TimeStamp ::: " +sqlTS);

return sqlTS;

}

Ganesh Babu N R

Java: Simple XML Generator

2009-03-14T05:40:00.000-07:00

Here is a simple Java program that generates an XML output using "xstream-1.3".

package xstreamtest;

import com.thoughtworks.xstream.XStream;

public class XStreamTest

{

public static void main(String[] args)

{

/* to construct XML from Person.class */

Person p = new Person();

p.setFirstName("Rama");

p.setLastName("Seetha");

// for this you require xstream-1.3.jar in the classpath

XStream xs = new XStream();

xs.alias("personXML", Person.class);

String _xml = xs.toXML(p);

System.out.println(_xml);

/* to reconstruct the Person object from XML */

//XStream xsp = new XStream(new DomDriver()); //if you do not wish

//to have xpp3 in the class path, you can have JAXP DOM parser

//for this you require xpp3_min-1.1.4c.jar in the classpath

Person pp = (Person)xs.fromXML(_xml);

}

###############

package xstreamtest;

public class Person

{

public String firstName = "Ganesh";

public String lastName = "Sindhu";

public void Person() {}

public Person getInstance(String fn, String ln)

{

Person person = new Person();

person.setFirstName(fn);

person.setLastName(ln);

return person;

}

public String setFirstName(String fn)

{

this.firstName = fn;

return firstName;

}

public String setLastName(String ln)

{

this.lastName = ln;

return lastName;

}

Ganesh Babu N R

Login App with Spring Framework

2009-01-10T03:05:00.000-08:00

Greetings and Warm Welcome to the World of Spring !!!

I generally get enthused only when I see something works right the first time. My intention was to create a simple “Login App” before getting deeper into Spring. I should thank so many hundreds of people who have posted so much material on Spring – without which I would not have been able to write this up. Thanks to Google and all those Spring Authors.

Now lets start our simple project by defining the requirements.

Requirements:

A Login page for a user to provide Username and Password
Receive the provided User Credentials
Validate the provided User Credentials
Show Error Message in the Login Screen if the validation fails
Show the Main Page if Validation is successful

First let us see “what” needs to be created. You can find the “why” for each of these by googling or in books.

I used Netbeans 6.1 and I hope you too have the same. Eclipse should work fine too – but I not verified that.

Step-1: under WEB-INF/jsp/ directory Create login.htm – with a form – form field names being “username” and “password”

Step-2: Create the Databean for this form. Call it Login.java. Define getter and setter methods for the fields “username” and “password” – these variables are case-sensitive and should be ditto as defined in login.jsp

Step-3: Create Controller for this Form – LoginController.java

Step-4: Create LoginValidator.java

Step-5: Edit web.xml

Step-6: Edit gspringapp-servlet.xml

a. Define bean = Login

b. Define bean id = validator

c. Define bean id = messageSource [For Error Message to be shown in the login page]

Step-7: Create message.properties under /WEB-INF/classes and make an entry - “key-value” pair. The key is the “name” given in “LoginValidator” for RejectValue

Step-8: Save spring.tld under /WEB-INF/jsp directory

Step-9: Create main.jsp and save under WEB-INF/jsp/ directory

###SOURCE FILES###

###################

package com.springapp;

/**

* This is the Databean POJO

* This needs to have the getter and setter methods

* for the form login.htm

* All the variables should be same as defined in the html form

* Beware - it is case-sensitive

public class Login

{

private String username;

private String password;

public String getUsername()

{

return username;

}

public void setUsername(String username)

{

this.username = username;

}

public String getPassword()

{

return password;

}

public void setPassword(String password)

{

this.password = password;

}

###################

LoginFormController.java

package com.springapp;

import org.springframework.web.servlet.ModelAndView;

import org.springframework.web.servlet.mvc.SimpleFormController;

public class LoginFormController extends SimpleFormController

{

public LoginFormController()

{

setCommandClass(Login.class);

setCommandName("login");

setFormView("login");

setSuccessView("main");

//setSupportedMethods(String[] {"POST", "GET"});

}

@Override

public ModelAndView onSubmit(Object command)

{

return new ModelAndView(getSuccessView());

}

###################

LoginValidator.java

* To change this template, choose Tools | Templates

* and open the template in the editor.

package com.springapp;

import org.springframework.validation.Errors;

import org.springframework.validation.Validator;

/**

* @author nrganeshbabu

public class LoginValidator implements Validator {

public boolean supports(Class dummy) {

return dummy.equals(Login.class);

}

public void validate(Object command, Errors errors) {

if((loggy.getUsername()).equals(loggy.getPassword()))

{

errors.reject("invalidLogin");

}

###################

Message.properties

invalidLogin.login=Invalid Credentials-Username And Password Cannot Be Same

###################

Ref: http://book.javanb.com

Hope with the above source, you were able to create a simple Login Application.

Cheers and Good Luck...

Ganesh Babu N R