Teremos três implementações da interface LogHandler:
CDI Produces Disposes
Esté exemplo demostra como as anotações @Produces e @Disposes trabalham. Um LogFactory cria uma instância do LogHandler dependendo de um atributo "type". Para o propósito deste exemplo, o type é hard-coded para especificar um valor. Uma implementação Logger deve conter uma lista de LogHandlers.
-
Uma DatabaseHandler
-
Uma FileHandler
-
Uma ConsoleHandler
O DatabaseHandler aparentemente gravaria os logs em um banco de dados.
O FileHandler gravaria os logs em um arquivo.
O ConsoleHandler apenas imprimiria os logs para um console (saída padrão).
Esté exemplo é apenas uma ilustração de como os conceitos dentro do CDI funcionam e não destina-se a fornecer uma implementação/design de um framework de log.
ConsoleHandler
package org.superbiz.cdi.produces.disposes;
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.disposes;
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 conexão para gravar log no banco de dados
}
}FileHandler
package org.superbiz.cdi.produces.disposes;
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());
// Escreva para o arquivo de log
}
}LogFactory
package org.superbiz.cdi.produces.disposes;
import javax.enterprise.inject.Disposes;
import javax.enterprise.inject.Produces;
public class LogFactory {
private int type = 2;
@Produces
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!");
}
}
public void closeLogHandler(@Disposes LogHandler handler) {
switch (type) {
case 1:
System.out.println("Closing File handler!");
break;
case 2:
System.out.println("Closing DB handler!");
break;
case 3:
default:
System.out.println("Closing Console handler!");
}
}
}Logger
package org.superbiz.cdi.produces.disposes;
public interface Logger {
public void log(String s);
public LogHandler getHandler();
}LoggerImpl
package org.superbiz.cdi.produces.disposes;
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.disposes;
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.disposes;
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;
}
}Executando
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T E S T S
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Running org.superbiz.cdi.produces.disposes.LoggerTest
Apache OpenEJB 4.0.0-beta-1 build: 20111002-04:06
http://tomee.apache.org/
INFO - openejb.home = /Users/dblevins/examples/cdi-produces-disposes
INFO - openejb.base = /Users/dblevins/examples/cdi-produces-disposes
INFO - Using 'javax.ejb.embeddable.EJBContainer=true'
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 - Found EjbModule in classpath: /Users/dblevins/examples/cdi-produces-disposes/target/classes
INFO - Beginning load: /Users/dblevins/examples/cdi-produces-disposes/target/classes
INFO - Configuring enterprise application: /Users/dblevins/examples/cdi-produces-disposes
INFO - Configuring Service(id=Default Managed Container, type=Container, provider-id=Default Managed Container)
INFO - Auto-creating a container for bean cdi-produces-disposes.Comp: Container(type=MANAGED, id=Default Managed Container)
INFO - Enterprise application "/Users/dblevins/examples/cdi-produces-disposes" loaded.
INFO - Assembling app: /Users/dblevins/examples/cdi-produces-disposes
INFO - Jndi(name="java:global/cdi-produces-disposes/cdi-produces-disposes.Comp!org.apache.openejb.BeanContext$Comp")
INFO - Jndi(name="java:global/cdi-produces-disposes/cdi-produces-disposes.Comp")
INFO - Jndi(name="java:global/EjbModule10202458/org.superbiz.cdi.produces.disposes.LoggerTest!org.superbiz.cdi.produces.disposes.LoggerTest")
INFO - Jndi(name="java:global/EjbModule10202458/org.superbiz.cdi.produces.disposes.LoggerTest")
INFO - Created Ejb(deployment-id=cdi-produces-disposes.Comp, ejb-name=cdi-produces-disposes.Comp, container=Default Managed Container)
INFO - Created Ejb(deployment-id=org.superbiz.cdi.produces.disposes.LoggerTest, ejb-name=org.superbiz.cdi.produces.disposes.LoggerTest, container=Default Managed Container)
INFO - Started Ejb(deployment-id=cdi-produces-disposes.Comp, ejb-name=cdi-produces-disposes.Comp, container=Default Managed Container)
INFO - Started Ejb(deployment-id=org.superbiz.cdi.produces.disposes.LoggerTest, ejb-name=org.superbiz.cdi.produces.disposes.LoggerTest, container=Default Managed Container)
INFO - Deployed Application(path=/Users/dblevins/examples/cdi-produces-disposes)
##### Handler: @Produces created DatabaseHandler!, Writing to the database!
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0, Time elapsed: 1.02 sec
Results :
Tests run: 1, Failures: 0, Errors: 0, Skipped: 0