Problem !!! java.lang.ClassNotFoundException: [Ljava.lang.String

This, java.lang.ClassNotFoundException: [Ljava.lang.String is killing me a lot. I've suspected so many things about it, but actually is quite different. Its also mentioned in sun's bug database

Here are some of the solutions i've found in different sites;

1.http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6434149

This link recommends the following actions to solve this bug:

1) Add -Dsun.lang.ClassLoader.allowArraySyntax=true if you want to use a
library for which you don't have the source with JDK6

2) Change loader.loadClass( name ) to Class.forName( name, false, loader ) if
you own the code.

class org.apache.catalina.loader.WebAppClassLoader
uses this code to load classes:

clazz = loader.loadClass(name);

Can you please change the sections of code where this line is used (1352 and
others) to
clazz =  Class.forName( name, false, loader);

2. http://dev.bostone.us/2009/02/23/javaxfacesfacesexception-javalangclassnotfoundexception-ljavalangstring/

• jdk1.6 unlike 1.5 it will not attempt to load class (java.lang.String) by name by default
• it is easily solvable by locating JVM runtime in Eclipse's preferences (Window->Preferences->Installed JREs), highlighting the entry and adding runtime parameter -Dsun.lang.ClassLoader.allowArraySyntax=true

links:

• https://blog.coremedia.com/cm/post/2672591/RE_Java_6_javalangClassNotFoundException_LjavalangString_exception.html
• http://forums.java.net/jive/thread.jspa?threadID=15823

A simple secure MIME message SendMail function

Here is a simple secure MIME message sendMail function;

public boolean sendMail(String to, String subject, String text) {

Properties props = new Properties();

props.put("mail.transport.protocol", "smtp");

props.put("mail.smtp.host", Constants.SMTP_HOST_NAME);

props.put("mail.smtp.port", Constants.SMTP_HOST_PORT);

props.put("mail.smtp.auth", "true");

Authenticator auth = new SMTPAuthenticator();

Session mailSession = Session.getInstance(props, auth);

try{

Transport transport = mailSession.getTransport();

MimeMessage message = new MimeMessage(mailSession);

message.setFrom(new InternetAddress(Constants.SMTP_MESSAGE_SENDER));

message.addRecipient(Message.RecipientType.TO,

new InternetAddress(to));

message.setSubject(subject);

message.setHeader("MIM9

message.setHeader("Content-Type", "text/html");

message.setContent(text, "text/html");

transport.connect();

transport.sendMessage(message,

message.getRecipients(Message.RecipientType.TO));

transport.close();

return true;

} catch (MessagingException messagingException) {

messagingException.printStackTrace();

return false;

} catch (Exception exception){

exception.printStackTrace();

return false;

}

}

private class SMTPAuthenticator extends javax.mail.Authenticator {

public PasswordAuthentication getPasswordAuthentication() {

String username = Constants.SMTP_AUTH_USER;

String password = Constants.SMTP_AUTH_PWD;

return new PasswordAuthentication(username, password);

}

}

Oracle Sequence ID increase by double

if you are using trigger to generate sequence then might happened that the trigger is called twice. So to prevent from increasing the id value here is a little trick

CREATE OR REPLACE TRIGGER TRG_ABC BEFORE INSERT ON ABC
FOR EACH ROW
BEGIN
if :NEW.ID is null
then SELECT ABC_SEQ.NEXTVAL INTO :NEW.ID FROM DUAL;
end if;
END;

Oracle: use timestamp to convert string to date

http://www.xinotes.org/notes/note/422/

You can use the timestamp keyword to convert a string to Date:

select * from retail_transactions where posted_date >= timestamp '2008-12-01 00:00:00';

5 Regular Expressions Every Web Programmer Should Know

Here are 5 Regular Expressions Every Web Programmer Should Know

http://immike.net/blog/2007/04/06/5-regular-expressions-every-web-programmer-should-know/

How to convert String date into Date obj

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

try
{
Date today = df.parse("10/12/2009"); //converts String object into Date Object
System.out.println("Today = " + df.format(today)); //formats the Date object accourding to the format mentioned above
} catch (ParseException e)
{
e.printStackTrace();
}

Javascript confirm in aj4:commandLink in JSF

<a4j:commandLink onclick="if (! window.confirm('Are you sure?') ) {return false}" immediate = "true" >

don't forget to add immediate = 'true';

Setting Java Managed Bean into Session

FacesContext.getCurrentInstance().getExternalContext()
               .getSessionMap().put( "testBean",
                     testBean );

TestBean testBean = (TestBean)FacesContext.getCurrentInstance().getExternalContext()
               .getSessionMap().get( "testBean")

How-to get or remove a jsf backing bean from session?

To reset session bean

FacesContext

.getCurrentInstance()

.getApplication()

.createValueBinding( "#{yourBeanName}").setValue(FacesContext.getCurrentInstance(), null );

To get session bean reference

Object obj = FacesContext

.getCurrentInstance()

.getApplication()

.createValueBinding("#{yourBeanName}")

.getValue(FacesContext.getCurrentInstance());

 

YourSessionBean bean = (YourSessionBean)obj;

Prepended L in Exception

Have you ever saw an exception with L padded before a exception???

like .executeQuery(Ljava/lang/String;)Ljava/sql/ResultSet  while running an application in your application server ?

It means that this method cannot be found on server.

The solution is to restart the server...

ISO 8583 Encoder / Decoder

This page might help you if you want to encode and decode a test message

http://www.mitug.co.il/ISO8583Coder/default.aspx

Getting HTTP Session in JSF

source : http://itoday.wordpress.com/2007/04/08/getting-http-session-in-jsf/

Here is a way to get HttpSession...

import javax.faces.context.FacesContext;
// …..
public void addInSession() {
MySession mySession = new MySession();
mySession.setName(getMsg());
/* .getSession(bool), true if we want to create new session, if want to
use old
session then false
*/
FacesContext context = FacesContext.getCurrentInstance();
HttpSession session = (HttpSession) context.getExternalContext().getSession(false);
session.setAttribute(”sessionObj”, mySession);
if (session.getAttribute(”sessionObj”) != null) {
MySession mySavedSession = (MySession) session.getAttribute(”sessionObj”);
System.out.println(”HTTP Session: ” + mySavedSession.getName());
} else {
// do something
}
}

Configure OracleDataSource in Struts

Following is the configuration to be defined in <data-sources> and </data-sources>

Things to be remember while defining the OracleDataSource in Struts are

1. URL should be in uppercase otherwise it will throw following exception
   
   java.sql.SQLException: Invalid Oracle URL specified: OracleDataSource.makeURL
   
   
2. username and password should be defined in URL string and not separate property. Otherwise it will throw following exception
   
   java.sql.SQLException: invalid arguments in call
   

<data-source type="oracle.jdbc.pool.OracleDataSource"

key="ods">

<set-property property="driverClassName"

value="oracle.jdbc.driver.OracleDriver" />

<set-property property="URL"

value="jdbc:oracle:thin:username/password@localhost:1521:dbname" />

<!--

Maximum number of dB connections in pool. Make sure you

configure your mysqld max_connections large enough to handle

all of your db connections. Set to 0 for no limit.

-->

<!--

Maximum number of idle dB connections to retain in pool.

Set to 0 for no limit.

-->

<!--

Maximum time to wait for a dB connection to become available

in ms, in this example 5 seconds. An Exception is thrown if

this timeout is exceeded. Set to -1 to wait indefinitely.

-->

<set-property property="maxWait" value="5000" />

<set-property property="readOnly" value="true" />

<set-property property="autoCommit" value="false" />

</data-source>

Oracle 10g : How to pass ARRAYS to Oracle using Java?

Here i'm trying to send an array of integers as a parameter to a callablestatement.

import java.sql.CallableStatement;

import java.sql.Connection;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import java.sql.Types;

import javax.sql.DataSource;

import oracle.sql.ARRAY;

import oracle.sql.ArrayDescriptor;

import oracle.sql.StructDescriptor;

import com.cs.datasource.CardSellerDataSource;

public class TestMessageBroadCasting {

public static void main(String args[]) {

try {

DataSource dataSource = ... ...;

Connection connection = dataSource.getConnection();

String sql = "{call package_name.proc_name(?, ?, ?, ?, ?, ?)}";

Integer [] arr = {1 , 2};

ArrayDescriptor arrayDescriptor = ArrayDescriptor.createDescriptor(

"RESELLERLIST", connection);

ARRAY array = new ARRAY(arrayDescriptor, connection, arr);

CallableStatement callableStatement = (oracle.jdbc.driver.OracleCallableStatement)connection.prepareCall(sql);

callableStatement.setInt(1, 1);

callableStatement.setString(2, "A for apple"

+ System.currentTimeMillis());

callableStatement.setArray(3, array);

callableStatement.setString(4, "0");

callableStatement.setInt(5, 0);

callableStatement.setString(6, "");

callableStatement.registerOutParameter(4, Types.VARCHAR);

callableStatement.registerOutParameter(5, Types.INTEGER);

callableStatement.registerOutParameter(6, Types.VARCHAR);

callableStatement.execute();

String b = callableStatement.getString(6);

System.out.println("message : " + b);

} catch (SQLException e) {

e.printStackTrace();

}

}

}

So, first define an array of integer

Integer [] arr = {1 , 2};

We need a ArrayDescriptor.

ArrayDescriptor arrayDescriptor = ArrayDescriptor.createDescriptor(

"VALUELIST", connection);

VALUELIST is the name of the type defined in your database(Oracle)

Two points we need to note are 

1. VALUELIST must be defined in SCHEMA LEVEL rather than PACKAGE LEVEL
2. VALUELIST must always be typed in uppercase letter.

The errors you might get while not defining the name of the type well is

java.sql.SQLException: invalid name pattern: ... ...

Know the name of currently executing method in Java

This method is used to get the name of method currently executing.

protected String getCurrentlyExecutingMethodName() {
  Throwable t = new Throwable(); 
  StackTraceElement[] elements = t.getStackTrace(); 
  if (elements.length <= 0) return "[No Stack Information Available]";
  // elements[0] is this method
  if (elements.length < 2) return null;
  return elements[1].getMethodName();
}

Unable to open folder by double clicking...

If double clicking a folder opens search page then try one of the followings

1. in run type regsvr32 /i shell32.dll
   
2. Press Ok 

Or

1. In registry search for 'MountPoint2' and delete all entries