Out of container JNDI data source

问题:

I would like to configure a DataSource using JNDI in a Java SE app. What is the best way to do this?

So far, I've come across 2 projects:

1. Apache Naming. The project page has a specific example for configuring a data source, but it looks like the project is super old and no longer active.
2. JBossNS. It looks like it's easy to configure a local-only JNDI using LocalOnlyContextFactory, but I haven't found any docs on how to actually configure a data source.

If possible, I would like to also configure the data source with a JTA transaction manager (using JOTM?).

回答1:

Why are you using JNDI for this? It's not that it's a bad solution if you have a provider but there are alternatives such as dependency injection (IoC: via Spring or Guice).

The Spring JDBC data access is described here. The great thing is that you can use Spring to inject a DataSource into your code:

<bean class="com.my.Persister">
    <property name="dataSource" ref="dataSource" />
</bean>

The data source can be defined using a JNDI-lookup:

<jee:jndi-lookup id="dataSource" jndi-name="jdbc/MyDataSource" /> 

In a test environment, you could inject the data source directly:

<bean id="dataSource" class="apache.db.PoolingDataSource">
    <!-- config goes here -->
</bean>

回答2:

These references are pretty old but may help to use jnpserver (JBoss Naming Service provider):

• Working With JNDI In A J2SE Application
• Standalone JNDI server using jnpserver.jar

回答3:

A very easy to use solution for stand-alone JNDI is simple-jndi. It works like a charm as long as you only need it within a single JVM, since it's a library no network server.

回答4:

The Simple-JNDI version, referenced by klenkes74, is not under active development any more. Because I encountered some issues with it I forked it, did some bug fixes and implemented some new features. I already used the old version not only for testing but in production too because I prefer a Service Locator pattern over Dependency Injection although the latter one is more trendy nowadays.

You can easily use Simple-JNDI to define a DataSource or a connection pool declaratively and get it bound to a JNDI Context.

Define a jndi.properties file in your classpath:

java.naming.factory.initial=org.osjava.sj.SimpleContextFactory
org.osjava.sj.root=[absolute_or_relative_path_to_a_property_file]

The property file looks like:

type=javax.sql.DataSource
driver=org.gjt.mm.mysql.Driver
url=jdbc:mysql://localhost/testdb
user=testuser
password=testing

Now you can access your DataSource from inside your code this way:

  InitialContext ctxt = new InitialContext();
  DataSource ds = (DataSource) ctxt.lookup("name_of_your_datasource");

For more information see https://github.com/h-thurow/Simple-JNDI