Intro I'm writing a web service using JAX-WS, and deploying it in Tomcat. With a lot of difficulties I finally had some code written.
Problem Unfortunately, when trying to run it I get the following error:
Context is read only
Setting I'm writing a web service that queries multiple databases and returns a single result. For that purpose, in the init() method (marked with #PostConstruct), I create a series of DataSources that I add to the context.
This is how I create the pool (based on Tomcat documentation) and after its creation I add it to the context (based on this tutorial):
#PostConstruct
private void init(){
PoolProperties props = new PoolProperties();
props.setUrl("jdbc:postgresql://" + ...);
props.setUsername(...);
props.setPassword(...);
props.setJdbcInterceptors("org.apache.tomcat.jdbc.pool.interceptor.ConnectionState;" +
"org.apache.tomcat.jdbc.pool.interceptor.StatementFinalizer");
DataSource dataSource = new DataSource();
dataSource.setPoolProperties(propos);
Context ctx = new InitialContext(env);
ctx.bind("java:/comp/env/dbpool", dataSource);
}
And later I use it:
#WebMethod
public Result performQuery(QueryParameters params){
Context ctx = new InitialContext(env);
(DataSource) source = (DataSource) ctx.lookup("java:/comp/env/dbpool");
}
I deploy the web service on a Tomcat 7 server.
Question I understand after Google-ing that I cannot write into the Context on Tomcat. But how else could I solve this? From what I understand about JAX-WS I cannot just have a private variable holding a DataSource, right? I have to pass that DataSource using a Context, right?
The InitialContext is writable from the Tomcat code only, not from your client code. You must add your DataSource to your context.xml and it'll work.
Related
I am using Weblogic server to host the EJB application.
Now I have written code to lookup Datasource on server side which works fine
and search the Datasource if code look for specific name. See the line no 2 in below code.
dataSource = (DataSource) ic.lookup("jdbc/irisuatDS");
But my problem is I have 4 different environment let say Local, Dev, Stage and production. Is there any way where code can we written for generic DataSource. something like below lines without pointing to specific name.
When I use below piece of code it gives me error.
dataSource = (DataSource)ic.lookup("java:comp/env");
InitialContext ic = new InitialContext();
dataSource = (DataSource) ic.lookup("jdbc/irisuatDS");
dataSource = (DataSource)ic.lookup("java:comp/env");
Please let me know how can I resolve the issue.
I'm trying to understand establishing a database-connection with a DataSource Object and the JNDI API.
I'm working with Intellij UE and have a local Tomcat-8- and Postgres-Server running.
I proceed as mentioned in the Oracle Java Documentation:
Creating Instance of DataSource Class and Setting its Properties
org.postgresql.ds.PGSimpleDataSource dataSource = new org.postgresql.ds.PGSimpleDataSource();
dataSource.setServerName("localhost");
dataSource.setDatabaseName("db01");
dataSource.setUser("jwi");
dataSource.setPassword("password");
Registering DataSource Object with Naming Service That Uses JNDI API
Context ctx = null;
try {
ctx = new InitialContext();
ctx.bind("jdbc/localDB", dataSource);
} catch (NamingException e) {
e.printStackTrace();
}
The Oracle Documentation says:
With the properties set, the system administrator can register the BasicDataSource object with a JNDI (Java Naming and Directory Interface) naming service.
So my first Question is: What means to register a DataSource? Is my code obove already the registration of an DataSource Object to JNDI?
Using Deployed DataSource Object
try {
Context ctx = new InitialContext();
DataSource ds = (DataSource) ctx.lookup("jdbc/localDB");
dbCon = ds.getConnection();
...
In this code cutting IntelliJ always claims, that it can't resolve the method getConnection().
The Oracle Documentation says:
After a basic DataSource implementation is deployed by a system administrator, it is ready for a programmer to use.
So my second Question is: What exactly means deployed in this case? Creating a DataSource Instance and execute the registration with JDNI? Or does deployed mean the Tomcat context.xml and web.xml configuration (Tomcat 8 JNDI How-To)?
I'd really appreciate if anybody has a good step by step instruction for this issue, in fact that the Oracle Documentation isn't really clear about some points imho.
for the second question, deployed means that your datasource is declared in the context.xml in tomcat.
Here is an example of an oracle database (you have to change the driver for postgres) :
<Resource name="jdbc/myoracle" auth="Container"
type="javax.sql.DataSource" driverClassName="oracle.jdbc.OracleDriver"
url="jdbc:oracle:thin:#127.0.0.1:1521:mysid"
username="scott" password="tiger" maxTotal="20" maxIdle="10"
maxWaitMillis="-1"/>
After that, you can code the java part, for that you can watch this link http://www.javapractices.com/topic/TopicAction.do?Id=127
For a complete example, there's a good tutorial here http://alvinalexander.com/blog/post/java/how-configure-tomcat-dbcp-connection-pool-pooling-postgres.
Hope this help
I have configured MysqlDataSource in tomcat using this link.I have written junit test cases.when am i calling below connection from junit it throws following errors.
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
I have used following code
class DataConnection {
private static DataSource dataSource;
public DataConnection() {
try {
Context ctx = new InitialContext();
dataSource = (DataSource)ctx.lookup("java:comp/env/jdbc/test");
} catch (NamingException e) {
e.printStackTrace();
}
}
public static Connection getConnection() throws SQLException {
new DataConnection();
Connection con=dataSource.getConnection();
return con;
}
}
How to call tomcat from junit? How to achieve this?
The code you give gets the database connection from JNDI, e.g. when running in tomcat from the container. However, for Unit Tests (assuming that's what you use JUnit for) I'd rather suggest to use "dependency injection" - e.g. explicitly pass a database connection to the code under test or manually set it up before the test runs.
There's no need to rely on JNDI for executing your tests: That's not what you want to test, instead, you want to just verify that your actual code is running correctly.
You don't need any fancy library (e.g. spring) for dependency injection, just a slightly adjusted architecture. This will greatly enhance the testability of your application and lower the execution time of your tests.
(This is based on my assumptions of your situation based on the little bit of information that you give in your question)
Give TomcatJNDI a try. It is based on embedded Tomcat but initializes only Tomcat's JNDI environment without starting a server. So you can access all your resources as configured in Tomcat's configuration files in tests or from within any Java SE application. The API is simple. For instance to get a DataSource declared in context.xml:
TomcatJNDI tomcatJNDI = new TomcatJNDI();
tomcatJNDI.processContextXml(contextXmlFile);
tomcatJNDI.start();
Then you can lookup the DataSource as usual
DataSource ds = (DataSource) InitialContext.doLookup("java:comp/env/path/to/datasource")
More information about TomcatJNDI can be found here.
I'm creating a java enterprise application which uses activemq to send messages to a standalone queue broker.
I currently maintain access to long lived resources through jndi lookup which works quite nicely. I'd like to continue this pattern with the ActiveMQ connection factories and queue connection factories, however in the amq documentation it specifies that my jndi.properties should have:
java.naming.factory.initial = org.apache.activemq.jndi.ActiveMQInitialContextFactory
while the default jndi.properties (which works with my simple object and facade lookups has:
java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory
Can I use one with the other? Can I have two jndi.properties files or two initial contexts somehow?
This question shows how to configure ONLY activemq through jndi. I want them to play nicely together.
You can create any number of InitialContext objects you want. You just have to pass environment to its constructor to properly initialize it.
So you can still safely use jndi.properties and initialize initial context for activemq with the code which may look like this:
public void setUpActiveMQResources() throws IOException, NamingException {
InitialContext context = createInitialContext("/activemq.jndi.properties");
// do what you want
}
public InitialContext createInitialContext(String resource) throws IOException, NamingException {
InputStream is = getClass().getResourceAsStream(resource);
Properties props = new Properties();
try {
props.load(is);
} finally {
is.close();
}
return new InitialContext(props);
}
activemq.jndi.properties in that case is the classpath resource with content like here
I'm having problems calling EJB3 stateless bean outside the container.
Code for getting the object reference:
Context envCtx = (Context) context.lookup("ejb");
MyObject o = (MyObject) envCtx.lookup(MyObject);
The second row results in exception:
java.lang.ClassCastException: javax.naming.Reference
I use JBoss.org 5.1.0 GA.
Based on some other posts I suspect this might be due to wrong version of client libraries. However, I'm unsure which library jar(s) I should include in the jar? (I get the error using 5.0.4.GA jnpserver.)
For JBoss, your code should look something like that:
Properties properties = new Properties();
properties.put("java.naming.factory.initial","org.jnp.interfaces.NamingContextFactory");
properties.put("java.naming.factory.url.pkgs","=org.jboss.naming:org.jnp.interfaces");
properties.put("java.naming.provider.url","localhost:1099");
Context context = new InitialContext(properties);
(EchoBeanRemote) c.lookup("EchoBean/remote");
If you prefer, you can put the JNDI environement settings in a jndi.properties file (that needs to be on the classpath):
java.naming.factory.initial=org.jnp.interfaces.NamingContextFactory
java.naming.factory.url.pkgs=org.jboss.naming:org.jnp.interfaces
java.naming.provider.url=jnp://localhost:1099
And use the non-arg InitialContext constructor:
Context context = new InitialContext();
(EchoBeanRemote) c.lookup("EchoBean/remote");
This is obviously more portable.
And in both case, you'll need jbossall-client.jar on the classpath on the client side.
P.S.: You can check the Global JNDI Name your bean is registered at in the JNDI View of the web-based JMX console (if it still exists).