What does javax naming NoInitialContextException mean

Question

As the title suggests  what does  javax naming NoInitialContextException  mean in non technical terms  And what are some general suggestions to fix it   EDIT  From the console    javax naming NoInitialContextException  Need to specify class name in environment or system property  or as an applet parameter  or in an application resource file   java naming factory initial     at javax naming spi NamingManager getInitialContext NamingManager java 645      at javax naming InitialContext getDefaultInitCtx InitialContext java 288      at javax naming InitialContext getURLOrDefaultInitCtx InitialContext java 325      at javax naming InitialContext lookup InitialContext java 392      at cepars app ConnectionHelper getConnection ConnectionHelper java 25      at cepars app ConnectionHelper getConnection ConnectionHelper java 10      at cepars review ReviewDAO getJobList ReviewDAO java 30      at cepars review Test main Test java 43  java lang NullPointerException     at cepars review ReviewDAO getJobList ReviewDAO java 31      at cepars review Test main Test java 43  cepars app DAOException     at cepars review ReviewDAO getJobList ReviewDAO java 39      at cepars review Test main Test java 43

User · Answer

In extremely non-technical terms  it may mean that you forgot to put  ejb   or  jdbc   or something at the very beginning of the URI you are trying to connect

User · Answer

It basically means that the application wants to perform some  naming operations   e g  JNDI or LDAP lookups   and it didn t have sufficient information available to be able to create a connection to the directory server   As the docs for the exception state      This exception is thrown when no   initial context implementation can be   created  The policy of how an initial   context implementation is selected is   described in the documentation of the   InitialContext class    And if you dutifully have a look at the javadocs for InitialContext  they describe quite well how the initial context is constructed  and what your options are for supplying the address credentials etc   If you have a go at creating the context and get stuck somewhere else  please post back explaining what you ve done so far and where you re running aground

User · Answer

Just read the docs      This exception is thrown when no   initial context implementation can be   created  The policy of how an initial   context implementation is selected is   described in the documentation of the   InitialContext class        This exception can be thrown during   any interaction with the   InitialContext  not only when the   InitialContext is constructed  For   example  the implementation of the   initial context might lazily retrieve   the context only when actual methods   are invoked on it  The application   should not have any dependency on when   the existence of an initial context is   determined    But this is explained much better in the docs for InitialContext

User · Answer

It means that there is no initial context     But seriously folks  JNDI  javax naming  is all about looking up objects or resources from some directory or provider  To look something up  you need somewhere to look  this is the InitialContext   NoInitialContextException means  I want to find the telephone number for John Smith  but I have no phonebook to look in    An InitialContext can be created in any number of ways  It can be done manually  for instance creating a connection to an LDAP server  It can also be set up by an application server inside which you run your application  In this case  the container  application server  already provides you with a  phonebook   through which you can look up anything the application server makes available  This is often configurable and a common way of moving this type of configuration from the application implementation to the container  where it can be shared across all applications in the server   UPDATE  from the code snippet you post it looks like you are trying to run code stand-alone that is meant to be run in an application server  In this case  the code attempting to get a connection to a database from the  phonebook   This is one of the resources that is often configured in the application server container  So  rather than having to manage configuration and connections to the database in your code  you can configure it in your application server and simple ask for a connection  using JNDI  in your code

[java] What does "javax.naming.NoInitialContextException" mean?

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