CDI field producer
This example shows the usage of the @Produces annotation. @Produces is a CDI mechanism which allows defining a source
for injection. This example shows one of two ways of declaring a producer. Instead of a producer method (see CDI-produces-disposes example)
a producer field can be used. A producer field can be used instead of a simple getter method. It could be used to inject resources, such as persistence contexts. One caveat to using producer fields over producer
methods is that a @Disposes method cannot be used in conjunction with @Produces field.
ConsoleHandler
package org.superbiz.cdi.produces.field;
public class ConsoleHandler implements LogHandler {
private String name;
public ConsoleHandler(String name) {
this.name = name;
}
@Override
public String getName() {
return name;
}
@Override
public void writeLog(String s) {
System.out.printf("##### Handler: %s, Writing to the console!\n", getName());
}
}
DatabaseHandler
package org.superbiz.cdi.produces.field;
public class DatabaseHandler implements LogHandler {
private String name;
public DatabaseHandler(String name) {
this.name = name;
}
@Override
public String getName() {
return name;
}
@Override
public void writeLog(String s) {
System.out.printf("##### Handler: %s, Writing to the database!\n", getName());
// Use connection to write log to database
}
}
FileHandler
package org.superbiz.cdi.produces.field;
public class FileHandler implements LogHandler {
private String name;
public FileHandler(String name) {
this.name = name;
}
@Override
public String getName() {
return name;
}
@Override
public void writeLog(String s) {
System.out.printf("##### Handler: %s, Writing to the file!\n", getName());
// Write to log file
}
}
LogFactory
package org.superbiz.cdi.produces.field;
import javax.enterprise.inject.Produces;
public class LogFactory {
private int type = 2;
@Produces
LogHandler handler;
public LogFactory(){
handler = getLogHandler();
}
public LogHandler getLogHandler() {
switch (type) {
case 1:
return new FileHandler("@Produces created FileHandler!");
case 2:
return new DatabaseHandler("@Produces created DatabaseHandler!");
case 3:
default:
return new ConsoleHandler("@Produces created ConsoleHandler!");
}
}
}
Logger
package org.superbiz.cdi.produces.field;
public interface Logger {
public void log(String s);
public LogHandler getHandler();
}
LoggerImpl
package org.superbiz.cdi.produces.field;
import javax.inject.Inject;
import javax.inject.Named;
@Named("logger")
public class LoggerImpl implements Logger {
@Inject
private LogHandler handler;
@Override
public void log(String s) {
getHandler().writeLog(s);
}
public LogHandler getHandler() {
return handler;
}
}
LogHandler
package org.superbiz.cdi.produces.field;
public interface LogHandler {
public String getName();
public void writeLog(String s);
}
beans.xml
<beans xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/beans_1_0.xsd">
</beans>
LoggerTest
package org.superbiz.cdi.produces.field;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import javax.ejb.embeddable.EJBContainer;
import javax.inject.Inject;
import javax.naming.Context;
import static junit.framework.Assert.assertNotNull;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
public class LoggerTest {
@Inject
Logger logger;
private Context ctxt;
@Before
public void setUp() {
try {
ctxt = EJBContainer.createEJBContainer().getContext();
ctxt.bind("inject", this);
} catch (Exception e) {
e.printStackTrace();
}
}
@After
public void cleanUp() {
try {
ctxt.unbind("inject");
ctxt.close();
} catch (Exception e) {
e.printStackTrace();
}
}
@Test
public void testLogHandler() {
assertNotNull(logger);
assertFalse("Handler should not be a ConsoleHandler", logger.getHandler() instanceof ConsoleHandler);
assertFalse("Handler should not be a FileHandler", logger.getHandler() instanceof FileHandler);
assertTrue("Handler should be a DatabaseHandler", logger.getHandler() instanceof DatabaseHandler);
logger.log("##### Testing write\n");
logger = null;
}
}
Running
-------------------------------------------------------
T E S T S
-------------------------------------------------------
Running org.superbiz.cdi.produces.field.LoggerTest
INFO - ********************************************************************************
INFO - OpenEJB http://tomee.apache.org/
INFO - Startup: Thu May 10 01:28:19 CDT 2012
INFO - Copyright 1999-2012 (C) Apache OpenEJB Project, All Rights Reserved.
INFO - Version: 7.0.0-SNAPSHOT
INFO - Build date: 20120510
INFO - Build time: 04:06
INFO - ********************************************************************************
INFO - openejb.home = /home/daniel/projects/openejb/source/openejb/examples/cdi-produces-field
INFO - openejb.base = /home/daniel/projects/openejb/source/openejb/examples/cdi-produces-field
INFO - Created new singletonService org.apache.openejb.cdi.ThreadSingletonServiceImpl@a81b1fb
INFO - succeeded in installing singleton service
INFO - Using 'javax.ejb.embeddable.EJBContainer=true'
INFO - Cannot find the configuration file [conf/openejb.xml]. Will attempt to create one for the beans deployed.
INFO - Configuring Service(id=Default Security Service, type=SecurityService, provider-id=Default Security Service)
INFO - Configuring Service(id=Default Transaction Manager, type=TransactionManager, provider-id=Default Transaction Manager)
INFO - Creating TransactionManager(id=Default Transaction Manager)
INFO - Creating SecurityService(id=Default Security Service)
INFO - Inspecting classpath for applications: 26 urls. Consider adjusting your exclude/include. Current settings: openejb.deployments.classpath.exclude='', openejb.deployments.classpath.include='.*'
INFO - Searched 26 classpath urls in 2015 milliseconds. Average 77 milliseconds per url.
INFO - Beginning load: /home/daniel/projects/openejb/source/openejb/examples/cdi-produces-field/target/classes
INFO - Configuring enterprise application: /home/daniel/projects/openejb/source/openejb/examples/cdi-produces-field
INFO - Auto-deploying ejb cdi-produces-field.Comp: EjbDeployment(deployment-id=cdi-produces-field.Comp)
INFO - Configuring Service(id=Default Managed Container, type=Container, provider-id=Default Managed Container)
INFO - Auto-creating a container for bean cdi-produces-field.Comp: Container(type=MANAGED, id=Default Managed Container)
INFO - Creating Container(id=Default Managed Container)
INFO - Using directory /tmp for stateful session passivation
INFO - Enterprise application "/home/daniel/projects/openejb/source/openejb/examples/cdi-produces-field" loaded.
INFO - Assembling app: /home/daniel/projects/openejb/source/openejb/examples/cdi-produces-field
INFO - ignoreXmlConfiguration == true
INFO - ignoreXmlConfiguration == true
INFO - existing thread singleton service in SystemInstance() org.apache.openejb.cdi.ThreadSingletonServiceImpl@a81b1fb
INFO - OpenWebBeans Container is starting...
INFO - Adding OpenWebBeansPlugin : [CdiPlugin]
INFO - All injection points were validated successfully.
INFO - OpenWebBeans Container has started, it took [69] ms.
INFO - Deployed Application(path=/home/daniel/projects/openejb/source/openejb/examples/cdi-produces-field)
##### Handler: @Produces created DatabaseHandler!, Writing to the database!
INFO - Undeploying app: /home/daniel/projects/openejb/source/openejb/examples/cdi-produces-field
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 3.79 sec
Results :
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0