I want to inject the content of EJB class to object variable with lookup function but not found the path. Following is my cod in javaEE:
PrintWriter out = response.getWriter();
out.println("this is the flight details:.....");
try{
Context context = new InitialContext();
Object ob = context.lookup("java:global/ejb1/SourcePackage/FlightService!com.airline.service.FlightService");
fs = (FlightService)ob;
}
catch(Exception e){
out.println("not found path");
}
and my structure of project is :
First of all I think is better to understand what wrong with annotation, cause injecting bean is simpler and controls by container not you. Lookup is a choice only when you are tryin to get access to ejb from another jvm.
Secondly your path is wrong. You use module-name instead of app-name and Source package is a IDE specific thing. Path in JNDI is based on built jar file.
As described in EJB specification global name creates by following pattern
java:global[/<app-name>]/<module-name>/<bean-name>[!<fully-qualified-interface-name>]
where in your case
app-name normally ear name
module-name normally EJB jar name (in
your case ejb1)
bean-name is simple name of class with annotation
Stateless, Statefull, Singleton.
interface name is canonical name of implemented interface
Related
I am absolutely confused with application context in spring. If i use spring (simple spring) create a beans.xml and then invoke Application context from (for example) main() method.
ApplicationContext context = new FileSystemXmlApplicationContext
("C:/Users/ZARA/workspace/HelloSpring/src/Beans.xml");
all works well. But I don't understand if i move file on directory above or in another directory(for example) it will be ok?
in spring-mvc there is context for each DispatcherServlet which i create and where i specify some beans, there is common context for all servlets, how to specify this? in web.xml?
in general, please explain me this moment (I read spring in action, i undesrstand almost all, but these tricky moment isn't shown there.
From FileSystemXmlApplicationContext java doc:
Standalone XML application context, taking the context definition files from the file system or from URLs, interpreting plain paths as relative file system locations (e.g. "mydir/myfile.txt"). Useful for test harnesses as well as for standalone environments.
The key words here are context definition files, so you can pass paths to as many xml-files, as you want. Besides that, you can create an application context and pass it to the new one as a parent:
FileSystemXmlApplicationContext(String[] configLocations, ApplicationContext parent)
Thus you can easily create the needed hierarchy of contexts.
ApplicationContext parentContext = new FileSystemXmlApplicationContext
("C:/some/path/ParentBeans.xml");
ApplicationContext childContext = new FileSystemXmlApplicationContext
(new String[]{"C:/some/path/ChildBeans1.xml", "C:/some/path/ChildBeans2.xml"}, parentContext);
if i move file on directory above all in another directory(for example) it will be ok?
As long as your path to file is correct and reachable - it's Ok.
I am new to Java EE world, in my application I would like to connect to the Database. I was able to accomplish this task with the code below, but can someone explains it to me? What each line does?
code:
try {
InitialContext initContext = new InitialContext();
Context env = (Context) initContext.lookup("java:comp/env");
ds = (DataSource) env.lookup("jdbc/test2");
} catch (NamingException e) {
throw new ServletException();
}
I also found out that I can use the annotation below in my JSP using tomcat which accomplish the same result as above. Can I use this annotation with any web server, ex GlassFish or Jboos ?
Anotation code:
#Resource(name = "jdbc/test2")
private DataSource ds;
The Java Naming and Directory Interface™ (JNDI) is an application
programming interface (API) that provides naming and directory
functionality to applications written using the Java™ programming
language. 1
The Context object provides the methods for binding names to objects, unbinding names from objects, renaming objects and listing the bindings.
JDNI performs all naming operations relative to a context. Therefore the JDNI defines an InitialContext, which provides a starting point for naming and directory operations. Once you have an initial context, you can use it to look up other contexts and objects.
Many methods in the JDNI package throw a NamingException when they need to indicate that the operation requested cannot be performed. The JDNI has a rich exception hierarchy stemming from the NamingException class. The class names of the exceptions are self-explanatory and are listed here.
You can use the #Resource annotation to inject resources. You can find more information on the correct use here.
Sources:
https://docs.oracle.com/javase/tutorial/jndi/overview/index.html
http://www.javaworld.com/article/2076888/core-java/jndi-overview--part-1--an-introduction-to-naming-services.html
I'm trying to run a remote lookup to another Glassfish from a Servlet. So, I was following the link documentation (http://docs.oracle.com/cd/E19798-01/821-1752/beanv/index.html). First I created a Sateless Session Ben called CalculatorBean, packaged in an EJB JAR of the same name (CalculatorBean), the JNDI name was java:global/CalculatorBean/CalculatorBean.
According to the documentation, I created a Web project and declared my EJB in sub-web.xml the following file:
<ejb-ref>
<ejb-ref-name>ejb/CalculatorBean</ejb-ref-name>
<jndi-name>corbaname:iiop:127.0.0.1:3700#CalculatorBean/CalculatorBean</jndi-name>
</ejb-ref>
where 127.0.0.1 is the host of the machine (local!), 3700 is the default port for querying and, CalculatorBean/CalculatorBean is the global JNDI name. First question, theoretically the JNDI name passes into an interoperable String "CalculatorBean/CalculatorBean" instead of "java: global/CalculatorBean/CalculatorBean", right?
After that, I created a Servlet and put the following code snippet:
ctx = new InitialContext ();
bean = (CalculatorRemote) ctx.lookup ("java:comp/env/ejb/CalculatorBean");
Where, CalculatorRemote is the name of the remote interface that we included in the java project:comp/env/ is the directory section to access Java EE components and ejb/CalculatorBean is the name of my bean in the configuration of the sun-web.xml file
When put to run my Servlet I'm getting the exception:
Caused by: javax.naming.NameNotFoundException: No object bound to name java:comp/env/ejb/CalculatorBean
Obviously, it's not finding the name, however, do not really know what name I should use to set the lookup.
I had the same problem, and I solved it.
By default, your EJB is not visilbe into java:comp/env/ and you can not lookup for an EJB into InitialContext instance. But, you can successful lookup for an EJB after when at least one EJB instance is injected using #EJB annotation, like, for your example:
#EJB(name = "ejb/CalculatorBean")
private CalculatorRemote calc;
After that, CalculatorRemote EJB is visible in InitialContext instance.
Helo masters, I have to create a JNDI Datasource dynamically, I tried to do it with a listener called SetupApplicationListener. Here is the beginning of WEB-LIB/web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee">
<display-name>pri-web</display-name>
<!-- Listeners -->
<listener>
<listener-class>org.apache.myfaces.webapp.StartupServletContextListener</listener-class>
</listener>
<listener>
<listener-class>myapp.SetupApplicationListener</listener-class>
</listener>
The code of the listener:
public class SetupApplicationListener implements ServletContextListener {
public static Log LOG = null;
public void contextInitialized(ServletContextEvent ctx){
try {
createOracleDataSource();
.....
}
}
private void createOracleDataSource() throws SQLException, NamingException {
OracleDataSource ds = new OracleDataSource();
ds.setDriverType(...);
ds.setServerName(...);
ds.setPortNumber(...);
ds.setDatabaseName(...);
ds.setUser(...);
ds.setPassword(...);
new InitialContext().bind("java:comp/env/jdbc/myDS", ds);
}
.....
}
And there is the error:
[ERROR] 29/01/2013 09:44:50,517 (SetupApplicationListener.java:86) -> Error
javax.naming.NamingException: Context is read only
at org.apache.naming.NamingContext.checkWritable(NamingContext.java:903)
at org.apache.naming.NamingContext.bind(NamingContext.java:831)
at org.apache.naming.NamingContext.bind(NamingContext.java:171)
at org.apache.naming.NamingContext.bind(NamingContext.java:187)
at org.apache.naming.SelectorContext.bind(SelectorContext.java:186)
at javax.naming.InitialContext.bind(InitialContext.java:359)
at myapp.SetupApplicationListener.createOracleDataSource(SetupApplicationListener.java:102)
Can I set the read-only properties of the Context to "true"? Thanks! :)
Tomcat 6.0
Oracle 11g
jdk1.5
EDIT: Don't need to be dynamically, i have to define a jndi datasource internally I can't modify the server files because it is a shared server. It must be jndi because other modules use it in that way, thanks.
If you need to create a datasource dynamically is there really any need for a JNDI lookup? JNDI is designed to make the connection external to the application, while in your scenario its tightly coupled to the application due to a legitimate requirement. Why not just use a JDBC connection?
You need to create a ServletContextListener and there you can make the InitialContext writable - it's not the way it should be done, but if you really need it, this is one way you can do it.
This also works with Java Melody!
protected void makeJNDIContextWritable(ServletContextEvent sce) {
try {
Class<?> contextAccessControllerClass = sce.getClass().getClassLoader().loadClass("org.apache.naming.ContextAccessController");
Field readOnlyContextsField = contextAccessControllerClass.getDeclaredField("readOnlyContexts");
readOnlyContextsField.setAccessible(true);
Hashtable readOnlyContexts = (Hashtable) readOnlyContextsField.get(null);
String context = null;
for (Object key : readOnlyContexts.keySet()) {
String keyString = key + "";
if (keyString.endsWith(sce.getServletContext().getContextPath())) {
context = keyString;
}
}
readOnlyContexts.remove(context);
} catch (Exception ex) {
ex.printStackTrace();
}
}
I haven't got this problem before since I usually defined JNDI in application server(tomcat, weblogic and etc). Just like what Kevin said, this is exactly what JNDI was designed for; separating datasource config from your source code and retrieving JNDI resources through lookup and inject;
Back to your question, I think tomcat has every strict rules on modifying JNDI at runtime. In another word, you cannot re-bind or remove jndi from Context. If you go through the tomcat specification you will probably see some thing about jndi lookup but no re-bind.
From section EE.5.3.4 of the EE 6 platform specification (JSR 316):
The container must ensure that the application component instances
have only read access to their naming context. The container must
throw the javax.naming.OperationNotSupportedException from all the
methods of the javax.naming.Context interface that modify the
environment naming context and its subcontexts.
Note that "their naming context" in this section is referring to java:comp.
I solved this problem when found that I was closing environmentContext object
For example:
Context context=new InitialContext();
Context environmentContext=(Context) context.lookup("java:comp/env");
And my code was:
environmentContext.close();
After removing close function from environmentContext problem was solded for me;
I also had this problem, but being new to Tomee, I didn't know that there is a simple solution. When I deployed my web app to the webapps folder, the app worked fine, but when I deployed it to a service folder, I got the same abort. The problem was that the folder name did not match the war name (minus the .war). Once I fixed that, the app worked fine. Make sure the war name, folder name and service name are identical. This problem produces several different errors, including Context is read only and Error merging Java EE JNDI entries.
I solved this issue by setting useNaming="false" in my context.xml.
From the documentation:
useNaming : Set to true (the default) to have Catalina enable a JNDI InitialContext for this web application that is compatible with Java2 Enterprise Edition (J2EE) platform conventions.
Here's my Java class
import endpoint.NewSessionRemote;
import javax.naming.Context;
import javax.naming.InitialContext;
public class HelloClient {
public static void main(String[] args) {
try {
Context ctx = new InitialContext();
NewSessionRemote hello = (NewSessionRemote) ctx.lookup("endpoint.NewSessionRemote");
System.out.println(hello.stringChange(4));
} catch (Exception ex) {
ex.printStackTrace();
}
}
}
When I run this class I'm getting an exception.
javax.naming.NameNotFoundException: endpoint.NewSessionRemote not found
at com.sun.enterprise.naming.TransientContext.doLookup(TransientContext.java:216)
at com.sun.enterprise.naming.TransientContext.lookup(TransientContext.java:188)
at com.sun.enterprise.naming.SerialContextProviderImpl.lookup(SerialContextProviderImpl.java:74)
at com.sun.enterprise.naming.RemoteSerialContextProviderImpl.lookup(RemoteSerialContextProviderImpl.java:129)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at com.sun.corba.ee.impl.presentation.rmi.ReflectiveTie._invoke(ReflectiveTie.java:154)
at com.sun.corba.ee.impl.protocol.CorbaServerRequestDispatcherImpl.dispatchToServant(CorbaServerRequestDispatcherImpl.java:687)
at com.sun.corba.ee.impl.protocol.CorbaServerRequestDispatcherImpl.dispatch(CorbaServerRequestDispatcherImpl.java:227)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleRequestRequest(CorbaMessageMediatorImpl.java:1846)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleRequest(CorbaMessageMediatorImpl.java:1706)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleInput(CorbaMessageMediatorImpl.java:1088)
at com.sun.corba.ee.impl.protocol.giopmsgheaders.RequestMessage_1_2.callback(RequestMessage_1_2.java:223)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.handleRequest(CorbaMessageMediatorImpl.java:806)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.dispatch(CorbaMessageMediatorImpl.java:563)
at com.sun.corba.ee.impl.protocol.CorbaMessageMediatorImpl.doWork(CorbaMessageMediatorImpl.java:2567)
at com.sun.corba.ee.impl.orbutil.threadpool.ThreadPoolImpl$WorkerThread.run(ThreadPoolImpl.java:555)
java.lang.NullPointerException
All the other enterprise bean classes are written according to the EJB 3.0 standard.
Your valuable contribution is expected.
Solution
The exception was
javax.naming.NameNotFoundException: endpoint.NewSessionRemote not found
It occurs because the JNDI name that was given by the application side didn't match the servser's (Glassfish) actual JNDI name, so I did was check the JNDI tree in Glassish through its admin console (vendor specific) and I did notice that the JNDI for the NewSessionRemote interface (which is the business interface of the session bean NewSessionBean) is different from the name which I have given in the application side. So how did this happen then suddenly something came in to my mind that's the ejb-jar.xml there is another name JNDI name assigned to the same NewSessionRemote using tag. So I simply remove it and redeploy EJB module. That's it.
Looks like you have no RMI registry (i.e. active server) you are lookingUp() against.
You supplied no Context.INITIAL_CONTEXT_FACTORY variable, so the lookup should be a valid URL, which it is not.
Hence, you should put something like this on your env (on the iCtx):
env.put(Context.INITIAL_CONTEXT_FACTORY, "com.sun.jndi.rmi.registry.RegistryContextFactory");
I suggest you read the the simple examples over at http://java.sun.com/j2se/1.5.0/docs/guide/jndi/jndi-rmi.html
When using JNDI, you're using an API that requires a specific configuration underlying it in order to connect to the server (see the Javadoc for details on what that configuration is). For example, java.naming.factory.initial is the property which indicates which implementation of JNDI you want to use.
Now, when running code inside a JavaEE server, this configuration is available implicitly, and all you need to do is what you have done in your code - instantiate InitialContext, and perform a lookup. However, when running outside the server, this implicit configuration is not present, and so you need to configure your InitialContext explicitly.
Your sample code uses a main() method, which suggests that you're running outside the container. The config you need will depend on your specific application server, you'll need to look up that documentation to see what config to supply.