Diagnosing Java memory leaks (OutOfMemoryError)

• First you have to get a Heap Dump.
• To analize it, IBM Heap Analyzer is the way to go.
• IBM Heap Analyzer's Tree View *is* the way to go.
• Hopefully you'll have one big tree. Go for it!
• Descend fast while the big percentage doesn't change. Ignore "interesting" objects if the percentage doesn't change under them.
• If you find a ClassLoader in the way, ignore the history behind you. Keep descending.
• Descend more.
• Be aware of "infinite chains" of the same objects or "infinite chains" with patterns of the same objects.
• Be aware of gaps in the percentage.
• Keep in mind that the tree Heap Analzyer is just a way to show you the memory. You have thousands of ways to draw an analogous tree. Each point in the tree can have several "parents". Heap Analyzer is only showing you one of them.

References:

• How to find Java Memory Leaks - Part 3

Programmatically obtaining "Messages waiting for read" for OC4J 10g JMS memory topic using JMX

You have to configure your classpath with the following jars (I haven´t test which of them are extrictly necessary):

• adminclient.jar
• dms.jar
• ejb.jar
• javax77.jar
• jms.jar
• oc4jclient.jar
• oc4j-internal.jar
• optic.jar
• pcl.jar

Although I'm working with OAS and not with OC4J standalone, I'll connect directly to the OC4J instance (not through OPMN). So I'll use this type of URL: service:jmx:rmi://[server]:[oc4j_rmi_port]. I just need to get the OC4J RMI port usign opmnctl -l.

Obtain the connection using the oc4jadmin credentials:

JMXServiceURL url = new JMXServiceURL(makeJmxUrl());
String[] creds = { "oc4jadmin", oc4jadminPassword };
Map<String, Object> env = new HashMap<String, Object>();
env.put(JMXConnector.CREDENTIALS, creds);
JMXConnector jmxc = JMXConnectorFactory.connect(url, env);
MBeanServerConnection mbsc = jmxc.getMBeanServerConnection();

The JMS topic I'm trying to obtain the statistics from is one of the Oracle ESB 10g standard topics: ESB Java Deferred. I have several subscribers and each one of them has a corresponding MBean. The statistics are presented from each one of them, and not as totals for the topic. So, if for example, I want to get the "Messages waiting for read" for the topic, I have to obtain the value for each subscriber and add them. The wildarded URL to obtain the MBeans for the subscribes is as follows: oc4j:j2eeType=JMSStoreResource,*,JMSDestinationResource=\"Topic.ESB Deferred Topic\",JMSResource=\"JMS\",J2EEServer=standalone

ObjectName mbeanNameQueryPattern = new ObjectName("oc4j:j2eeType=JMSStoreResource,*,JMSDestinationResource=\"Topic.ESB Deferred Topic\",JMSResource=\"JMS\",J2EEServer=standalone");
Set<ObjectName> mbeansNames = mbsc.queryNames(mbeanNameQueryPattern, null);

Iterate over the MBeans to obtain their statistics: There are several statistics to choose (messageCommitted, messageRolledBack, messageCount -Messages waiting for read-, messageDequeued -Messages waiting for commit-, messageEnqueued, messageDiscarded, messageExpired, messagePagedIn, messagePagedOut, messageRecovered and pendingMessageCount), but right now I'm only getting this: messageCount.

long value = 0L;
Iterator mbeansNamesIter = mbeansNames.iterator();
while (mbeansNamesIter.hasNext()) {
    ObjectName mbeanName = mbeansNamesIter.next();
    JMSStoreStatsImpl jmsStats = (JMSStoreStatsImpl)mbsc.getAttribute(mbeanName, "stats");
    CountStatisticImpl countStatistic = (CountStatisticImpl)jmsStats.getStatistic(statisticName);
    value = value + countStatistic.getCount();
}

Thos are the related imports:

import javax.management.MBeanServerConnection;
import javax.management.ObjectName;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;
import oracle.oc4j.admin.management.shared.statistic.CountStatisticImpl;
import oracle.oc4j.admin.management.shared.statistic.JMSStoreStatsImpl;

JVM must be started with this flag: -Djmx.remote.protocol.provider.pkgs=oracle.oc4j.admin.jmx.remote

If you want to make a "real time" desktop chart with the values, there's a very nice and easy alternative: VisualVM's charting API. Here is an example.

"Error creating managed object for class org.jboss.weld.servlet.WeldListener"

Following the Arun Gupta's Java EE 6 Hands-on Lab using Netbeans 7.0.1 and Glassfish 3.1.1, I found the following error, which prevented me from deploy the app: Error creating managed object for class org.jboss.weld.servlet.WeldListener.

I just restarted Glassfish, did a Clean and Build and the problem was gone :P

The Lab is a very good way to know several new cool Java EE 6 features.

"Oracle Web Services Inspection Language Configuration Assistant" failed ("Could not get DeploymentManager" deploying WSIL App)

Installing the 10.1.3.5 Oracle Application Server patch on an 10.1.3.1 installation, I got the following error in the "Configuration Assistants" step:

Configuration assistant "Oracle Web Services Inspection Language Configuration Assistant" failed
Buildfile: /ESB/webservices/lib/wsil-install.xml

The log windows didn't have any useful information so I took a look at the full installActions* log. This log didn't have also the concrete error but showed the complete Ant command being executed:

The command being spawned is: '/ESB/ant/bin/ant -buildfile /ESB/webservices/lib/wsil-install.xml  -logfile /ESB/cfgtoollogs/wsil.txt -DHOST=ESBDB -DOPMNPORT="6003" -DADMIN_USER=oc4jadmin -DOPMNINSTANCE=home -Denv.JAVA_HOME=/ESB/jdk -Denv.ANT_HOME=/ESB/ant -Denv.ORACLE_HOME=/ESB *Protected value, not to be logged*'

Luckily, this command had its own log file: /ESB/cfgtoollogs/wsil.txt.

This log had the following information:

[echo] Deploying WSIL App with JSSO disabled
[java] Failed at "Could not get DeploymentManager".
[java] This is typically the result of an invalid deployer URI format being supplied, the target server not being in a started state or incorrect authentication details being supplied.
[java] More information is available by enabling logging -- please see the Oracle Containers for J2EE Configuration and Administration Guide for details.

Watching other post (and other) I found this error occurs when there are errors in the arguments supplied in the deployment URL (OC4J instance, password, etc.). I looked the Ant script and found the OC4J instance being used to deploy the WSIL app was 'home', but I don't have an O4CJ instance called 'home'. My OC4J admin instance is called 'admin'.

I hardcoded the name of my real OC4J intance in the ANT buildfile, retried the action and the installation finished OK.

Configuración alternativa del Softphone (teléfono VoIP) de Une en Windows 7 (64 bits)

Hace poco estaba fuera de Colombia e intenté usar el Softphone de UNE en Windows 7 64bits para hacer llamadas "locales" en Medellín, pero no me fue posible. El software que ellos distribuyen es una versión preconfigurada de SJphone de SJ Labs. También descargué directamente la última versión de dicha página pero tampoco me fue posible. No recuerdo exáctamente el error y no guardé un pantallazo; creo que era "No active network interface". Intenté iniciarlo con compatibilidad a Windows XP, pero tampoco. He visto el softphone funcionando en otros sistemas Windows 7, pero en mi máquina no lo logré (depronto los otros eran 32 bits y la incompatibilidad es solo con 64 bits).

Afortunadamente me recomendaron otro programa bastante bueno y grátis para uso personal, llamado X-Lite.

Para configurarlo debes disponer solo de tu número telefónico de VoIP y tu contraseña. Suponiendo que te asignaron el número 1234567, la configuración sería la siguiente:

User ID: 1234567
Domain: une.net.co
Password:
Authorization name: toip1234567
Proxy SIP: epmvoip1.une.net.co

Y listo.

Como yo estaba en un lugar con un límite muy bajo de cuota de navegación (usando un móden móvil), modifiqué los codecs disponibles para dejar solo unos de menor calidad, pero de menor consumo de ancho de banda. Si el ancho de banda esto no es una limitante, esto no es necesario ya que la calidad es muy buena con los predefinidos.

Antes:

Después:

Ver también Configuración del Softphone (teléfono VoIP) de Une en iPad (o iPhone).

"package javax.xml.bind.annotation does not exist" using CXF's DynamicClientFactory in OC4J 10.1.3.x

I'm using CXF 2.4.2 and DynamicClientFactory in OC4J 10.1.3.4 (and 10.1.3.5).

When DynamicClientFactory tries to compile the dinamycally generated Java sources, the following errors occur:

INFO: Created classes: XXX, YYY, ...
 C:\..\org.apache.cxf.endpoint.dynamic.DynamicClientFactory@12f767-1314800629516-src\...\XXX.java:4: package javax.xml.bind.annotation does not exist
 import javax.xml.bind.annotation.XmlAccessType;
                                  ^
 C:\..\org.apache.cxf.endpoint.dynamic.DynamicClientFactory@12f767-1314800629516-src\...\YYY.java:4: package javax.xml.bind.annotation does not exist
 import javax.xml.bind.annotation.XmlAccessType;
                                  ^

I dug into the DynamicClientFactory code and found that setupClasspath, the method which sets the Classpath for the javac compilation iterates between the supplied ClassLoader (or the Context ClassLoader if none is supplied) and the SystemClassLoader extrating the ClassPath paths for each one; this extraction is done only if the ClassLoader in turn is an instance of URLClassLoader. In OC4J, the ClassLoaders are usually instances of oracle.classloader.PolicyClassLoader (which is not an instance of URLClassLoader). For this reason, the Classpath for the compilation is not correctly set.

There was a reported bug (CXF-2549) which gives a solution for Weblogic. I didn't find a good similar solution for OC4J to send a patch.

I found the necessary compilation libraries are the JAXB ones. What I did, before calling createClient, was to set a new URLClassLoader which include the JAXB jars:

URL[] jaxbUrls = null;

jaxbUrls = new URL[]{
  new URL("file:/C:/.../jaxb-api-2.2.1.jar"),
  new URL("file:/C:/.../jaxb-impl-2.2.1.1.jar"),
  new URL("file:/C:/.../jaxb-xjc-2.2.1.1.jar")
};

ClassLoader currentCL = Thread.currentThread().getContextClassLoader();

URLClassLoader urlCL = new URLClassLoader(jaxbUrls, currentCL);

client = dcf.createClient(xxx, yyy, urlCL, zzz);

The compilation is now succesful.

DynamicClientFactory internally creates another URLClassLoader which includes the newly generated classes and set it as the current thread's Context Class Loader; for this reason, when working with DynamicClientFactory in a multithreaded environment, there are some gotchas relating the ClassLoaders, but I thing this is material for another post.

EDIT: I found a better way to initialize the JAXB jars URL's array:

import oracle.classloader.PolicyClassLoader;
import oracle.classloader.SharedCodeSource;

Class someJaxbClazz = Class.forName("javax.xml.bind.annotation.XmlAccessType");
PolicyClassLoader jaxbClazzClassLoader = (PolicyClassLoader)someJaxbClazz.getClassLoader();
SharedCodeSource[] sharedCodeSources = jaxbClazzClassLoader.getCodeSources(false);

for(SharedCodeSource sharedCodeSource : sharedCodeSources) {
    URL location = sharedCodeSource.getLocation();
    if(location.toString().toLowerCase().contains("jaxb")) {
        System.out.println("JAXB jar URL found->" + location);
    }
}

In my case, it printed somethig like:

JAXB jar URL found->file:/C:/.../cxf/2.4.2/jaxb-api-2.2.1.jar
JAXB jar URL found->file:/C:/.../cxf/2.4.2/jaxb-impl-2.2.1.1.jar
JAXB jar URL found->file:/C:/.../cxf/2.4.2/jaxb-xjc-2.2.1.1.jar

:-)

"compiler was unable to honor this globalBindings customization" using CXF's DynamicClientFactory

I'm using CXF 2.4.2 and DynamicClientFactory. To simplify the runtime classes manipulation I wanted to make sure the generated Java clases didn´t contain JAXBElement attributes; so I created the famous generateElementProperty globalBindings JAXB binding file.

I used the createClient method that receives the binding list to feed DynamicClientFactory with my file, but I received the following JAXB error: compiler was unable to honor this globalBindings customization. It is attached to a wrong place, or its inconsistent with other bindings.

I found this error may occur if you use more than one binding file with globalBindings declarations. I dug into the DynamicClientFactory code and found that by default, CXF use one binding file with globalBindings declarations: /org/apache/cxf/endpoint/dynamic/simple-binding.xjb in the addSchemas method. Thus, besides my binding file, there was another file internally used by CXF. Luckily, the binding file included by CXF have the generateElementProperty declaration that I was trying to configure with my binding file.

I checked the runtime generated classes and indeed (modifying the DynamicClientFactory class to not delete the source files) they did'n include the JAXBElement attributes when they would normally do.

It was no necesary to include my extra binding file.

This is a fragment of the stack trace:

Caused by: java.lang.reflect.UndeclaredThrowableException
    at $Proxy25.error(Unknown Source)
    at com.sun.tools.xjc.api.impl.s2j.SchemaCompilerImpl.error(SchemaCompilerImpl.java:286)
    at com.sun.tools.xjc.util.ErrorReceiverFilter.error(ErrorReceiverFilter.java:77)
    at com.sun.tools.xjc.util.ErrorReceiverFilter.error(ErrorReceiverFilter.java:77)
    at com.sun.tools.xjc.ErrorReceiver.error(ErrorReceiver.java:82)
    at com.sun.tools.xjc.reader.xmlschema.ErrorReporter.error(ErrorReporter.java:79)
    at com.sun.tools.xjc.reader.xmlschema.UnusedCustomizationChecker.check(UnusedCustomizationChecker.java:144)
    at com.sun.tools.xjc.reader.xmlschema.UnusedCustomizationChecker.check(UnusedCustomizationChecker.java:122)
    at com.sun.tools.xjc.reader.xmlschema.UnusedCustomizationChecker.schema(UnusedCustomizationChecker.java:199)
    at com.sun.tools.xjc.reader.xmlschema.UnusedCustomizationChecker.run(UnusedCustomizationChecker.java:95)
    at com.sun.tools.xjc.reader.xmlschema.BGMBuilder._build(BGMBuilder.java:187)
    at com.sun.tools.xjc.reader.xmlschema.BGMBuilder.build(BGMBuilder.java:116)
    at com.sun.tools.xjc.ModelLoader.annotateXMLSchema(ModelLoader.java:415)
    at com.sun.tools.xjc.api.impl.s2j.SchemaCompilerImpl.bind(SchemaCompilerImpl.java:245)
    ... 32 more
Caused by: java.lang.reflect.InvocationTargetException
    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:592)
    at org.apache.cxf.common.util.ReflectionInvokationHandler.invoke(ReflectionInvokationHandler.java:52)
    ... 46 more
Caused by: java.lang.RuntimeException: 

    Error compiling schema from WSDL at {http://xxx?wsdl}: compiler was unable to honor this globalBindings customization. It is attached to a wrong place, or its inconsistent with other bindings.
    at org.apache.cxf.endpoint.dynamic.DynamicClientFactory$InnerErrorListener.error(DynamicClientFactory.java:582)
    ... 51 more
Caused by: com.sun.istack.SAXParseException2: compiler was unable to honor this globalBindings customization. It is attached to a wrong place, or its inconsistent with other bindings.
    ... 42 more

Update (2013/08/14): I tried the same codebase with CXF 2.6.1, but started having issues with JAXBElement attributes appearing in the generated Java classes. I dug again into the DynamicClientFactory code and found in SVN revision 1232564 ([CXF-4037] Allow dynamic client to use already parsed and processed schemas like the tooling does), the code section that included the default binding file (simple-binding.xjb) was removed. It haven't been included in posterior commits (last trunk revision now for DynamicClientFactory is 1502354).

This is one version of the DynamicClientFactory.java's removed code section:

if (simpleBindingEnabled) {
String id = "/org/apache/cxf/endpoint/dynamic/simple-binding.xjb";
LOG.fine("Loading the JAXB 2.1 simple binding for client.");
try {
Document doc = StaxUtils.read(getClass().getResourceAsStream(id));
compiler.parseSchema(id, doc.getDocumentElement());
} catch (XMLStreamException e) {
LOG.log(Level.WARNING, "Could not parse simple-binding.xsd", e);
}
}

Due to the fact my code is not expecting JAXBElement attributes in the generated classes, I'm including the binding (again) by myself.

My binding:

<bindings version="2.1"
  xmlns="http://java.sun.com/xml/ns/jaxb"
  xmlns:xjc="http://java.sun.com/xml/ns/jaxb/xjc">
  <bindings>
    <globalBindings>
      <xjc:generateElementProperty>false</xjc:generateElementProperty>
    </globalBindings>
  </bindings>
</bindings>

The CXF's equivalent binding:

<jaxb:bindings
  xmlns:jaxb="http://java.sun.com/xml/ns/jaxb" jaxb:version="2.0"
  xmlns:xjc="http://java.sun.com/xml/ns/jaxb/xjc" jaxb:extensionBindingPrefixes="xjc">
 
  <jaxb:globalBindings generateElementProperty="false">
    <xjc:simple />
  </jaxb:globalBindings>
</jaxb:bindings>

"Could not locate the launcher comand" running JDeveloper, Weblogic installers

My actual client has strong security restrictions in their employee's corporate laptops. Although I received the authorization to install JDeveloper 11g and Weblogic in one of them's laptop, the installers keep showing the "Could not locate the launcher comand" error.

I did't want to check security issues, so what I did was "extract" the exe installer contens and run the internal installer.jar jar file (double click on windows or java -jar installer.jar). The installation ran without problems.

If there's no a good compression utility at hand, you can use the “-Djava.io.tmpdir=C:\xxx" flag to obtain the exe internal files (the installer extract the files at this location and you can copy them while the error message is active; after you click the Ok button, the installer will erase them).

If you have Administrator privileges, just use Run As Administrator.

VERR_GENERAL_FAILURE importing Oracle SOA Pre-built VM

I downloaded and tried to import the pre-built VM for SOA on VirtualBox (in my 64bits Win 7 laptop), and I found this error: Could not create the clone medium (VERR_GENERAL_FAILURE).

After googling and finding nothing useful, I cheked the MD5 sum of the downloaded files. One was incorrect. I downloaded it again and the VM worked without problems.

I never before bothered cheking the MD5 sums, but I guess I'll do it from now.

Blackberry Curve 8250 + Gmail without filtered and archived messages

I was given a Blackberry Curve 8520 from my employer (ouch :-( ). I configured my Gmail account using the wizard (which supposedly now is using the "enhanced plug-in"), which only ask you for Username and Password.

In my Gmail account I receive lots of email and I have several filters; the mayority of them apply a label to the message and "archive" the message (Skip the Inbox). I don't want to receive those last messages in my Blackberry but I couldn't find a way to do it. I guess it's related to the IMAP usage of the Blackberry. Moreover, I had visual notificacitions for those archived messages but they didn't appear in the corresponding mailbox but did appear in the main general mailbox. I just want to receive the messages that I see in my Inbox in the Web.

What I did was delete the previously created Gmail accounts and create others with the following procedure:

• Setup → Email settings → Add → Other
• In E-mail address put a wrong address...for example xxx@ggggmail.com (I couldn't find a way to directly enter manually the mail settings)
• In password enter whatever you want
• Press Next. You'll see an error. Now you have the option to "provide the settings"...follow this link
• Email type: POP/IMAP
• Email address: correct the prevously entered address with your real Gmail adress (can be an Gmail Apps or for your domain adress)
• Password: your real password
• Email server: pop.gmail.com
• Username: the same Email Address

I guess this way I'll lost some functionality of the enhanced plug-in or IMAP protocol, but I just need the basic funcionality of receiving the most important mails (my inbox).

You have to enable POP in your Gmail settings.

UPDATE: I have just seen the Manage Labes section in Gmail, has options to show or not labels in IMAP, so I'll try IMAP again.

UPDATE: trying IMAP was a pain. At first try, it failed to configure saying I had to activate IMAP to "All Mail". I did it and I ended up receiving all the email I automatically archived through filters, which I didn't want to see in my Inbox. It seems that even if I manually configure IMAP, it ends using the Enhanced Gmail Plugin which mess up everithing.

UPDATE: I'll try removing the Enhanced Gmail Plugin using CrackUtil.

Getting started with Microsoft Biztalk 2010 (from 0)

I'm not from the Microsoft world. I have worked with ESB and BPEL products from the Java side (Websphere Process Server and ESB and Oracle SOA Suite) and now I "want" to try Biztalk. I know some C#. These are the steps I'm following.

Installation:

To install Microsoft Biztalk using a Virtual Machine with Windows Server 2008 in your 64 bit computer, follow this steps:

1. Download and install Oracle VirtualBox here 
2. Download Windows Server 2008 R2 with SP1 trial here 
3. Download SQL Server 2008 R2 trial here (follow the "Download SQL Server 2008 R2 Eval X86 Executable (1.31 Gb)" link). I don't know if you can use SQL Server 2008 R2 Express (the free edition).
4. Download Visual Studio 2010 Ultimate trial here. You can't use Visual Studio Express to develope on Biztalk.
5. Download Biztalk Server 2010 Developer Edition here (or you can also download the 120 days trial here)
6. Get a Office 2007 or Office 2010 installer (only if you want to try BAM).
7. Create a Virtual Machine for Windows Server 2008 in Oracle VirtualBox.
8. Install Windows Server 2008 R2 on the Virtual Machine (next, next, next)
9. Download the Biztalk installation guide (Installing BizTalk Server 2010 on Windows Server 2008 R2 and 2008.docx) here.
10. Install Visual Studio, SQL Server, Office Excel and Biztalk 2010 on Windows Server 2008 following the guide (is easy to follw).
11. Start learning, you have 180 days left :(

Basic documentation

• BizTalk Server Developer Center

Related blog posts

• BizTalk Server 2010 Exam : How to prepare?