Mysql cluster comes with jars for clusterj. I downloaded Mysql Cluster 7.2.7. In shared/java folder,clusterj-7.2.7.jar,clusterj-api-7.2.7.jar,etc. exist. But when I add them to my project class path and write my first Java application that uses clusterj, some classes like SessionFactory,Session,ClusterJHelper is not included in the available jars. In another words, in none of the my jars includes these classes and then I cannot import. Why ?
You are really need to download the latest MySQL Cluster 7.2. SessionFactory, Session, and ClusterJHelper included in
clusterj-7.2.10.jar
clusterj-api-7.2.10.jar
clusterjpa-7.2.10.jar
Related
I developer a web application using Java. When I deploy it to my application server (Jetty, Tomcat, JBoss, GlassFish, etc.) throws an error. I can see this error message in the stacktrace:
java.lang.ClassNotFoundException
Or
java.lang.NoClassDefFoundError
What does this mean and how can I fix it?
What does this mean?
First, let's see the meaning of java.lang.ClassNotFoundException:
Thrown when an application tries to load in a class through its string name using:
The forName method in class Class.
The findSystemClass method in class ClassLoader.
The loadClass method in class ClassLoader.
but no definition for the class with the specified name could be found.
Usually, this happens when trying to open a connection manually in this form:
String jdbcDriver = "...'; //name of your driver
Class.forName(jdbcDriver);
Or when you refer to a class that belongs to an external library and strangely this class cannot be loaded when the application server tries to deploy the application.
Let's see the meaning of java.lang.NoClassDefFoundError (emphasis mine):
Thrown if the Java Virtual Machine or a ClassLoader instance tries to load in the definition of a class (as part of a normal method call or as part of creating a new instance using the new expression) and no definition of the class could be found.
The searched-for class definition existed when the currently executing class was compiled, but the definition can no longer be found.
The last part says it all: the class existed at compile time i.e. when I compiled the application through my IDE, but it is not available at runtime i.e. when the application is deployed.
how can I fix it?
In Java web applications, all third party libraries used by your application must go in WEB-INF/lib folder. Make sure that all the necessary libraries (jars) are placed there. You can check this easily:
- <webapp folder>
- WEB-INF
- lib
+ jar1
+ jar2
+ ...
- META-INF
- <rest of your folders>
This problem usually arises for JDBC connectivity jars (MySQL, Derby, MSSQL, Oracle, etc.) or web MVC frameworks libraries like JSF or Spring MVC.
Take into account that some third party libraries rely on other third party libraries, so you have to add all of them in WEB-INF/lib in order to make the application work. A good example of this is RichFaces 4 libraries, where you have to download and add the external libraries manually.
Note for Maven users: you should not experience these problems unless you have set the libraries as provided, test or system. If set to provided, you're responsible to add the libraries somewhere in the classpath. You can find more info about the dependency scopes here: Introduction to the Dependency Mechanism
In case the library must be shared among several applications that will be deployed on your application server e.g. MySQL connector for two applications, there's another alternative. Instead of deploying two war files each with their own MySQL connector library, place this library in the common library folder of the server application, this will enable the library to be in the classpath of all the deployed applications.
This folder vary from application server.
Tomcat 7/8: <tomcat_home>/lib
JBoss 7/Wildfly: <jboss_home>/standalone/lib
The class must exist under WEB-INF/classes or be inside a .jar file under WEB-INF/lib. Make sure it does.
Same problem happen with me.
Might be possible one of your libraries are using some classes internal which is not available
in your lib or maven dependency pom.xml.
Thats means you have analyze your error logs and identify these classes and then import all dependencies in maven or lib folder.
I have fixed this error by the same way.
because some of my libraries are using activation.jar and json.jar internally.
I see there are other similar questions, but none of them cover my exact situation.
I'm migrating an Eclipse based web service from FreeBSD 9.2 and Tomcat7 over to FreeBSD 10.0 and Tomcat8. I've deployed my .war on the new server and it runs, right up until it has to do a SQL access, where it fails with "cannot load net.sourceforge.jtds.jdbc.Driver". I'm not sure what's missing. We don't load a driver in lib, it's all bundled into the one .war file (which works fine on the old machine). I've searched the tomcat config files to see if there's any pointers that need to be set, but I'm coming up empty.
Download the jTDS driver from here. Copy it into the Tomcats lib folder. Are you sure you are not using JNDI to retreive the datasource? If thats not the case, its better to include app specific jars in your project and not on the server, to avoid version conflicts with other projects.
Download ojdbc6 or ojdbc14 (which one usefull for Tomcat8)
copy to apache-tomcat-(version) >> lib file.
And in eclipse add ojdbc in Build Path >> order & export.
I'm running a JBoss server (inside Eclipse), with some Hibernate mixed in. I installed Oracle's ojdbc drivers from here:
Oracle Database 11g Release 2 JDBC Drivers
I specifically downloaded the file: ojdbc6dms_g.jar, which according to the site contains instrumentation to support DMS. However when I startup my AS server, I get the following:
Caused by: java.lang.ClassNotFoundException: oracle.dms.console.DMSConsole from [Module
"com.oracle:main" from local module loader #485fcf29 (roots: /usr/local/jboss-7.1.1-
final/modules)]
when the server is trying to get a new hibernate ejb exception.
I checked Oracle's jar file and sure enough it doesn't contain the class oracle.dms.console.DMSConsole, although from the notes on Oracle's site about the jar file, it seems like the jar file should contain the DMS classes.
Can anyone point me to the correct jar file? And when I do get the right file, where should this file be installed to, particularly with regards to Eclipse and JBoss?
Update: Just found another question asking the same thing here on SO.
The missing classes are indeed in dms.jar. But as I've seen asked elsewhere finding the dms.jar file is not easy. You won't find dms.jar at Oracle Database 11g Release 2 JDBC Drivers because as noted by Oracle: dms.jar is not shipped as part of the RDBMS product. It is only available as part of the Oracle Application Server product.
I hopped onto our server and grabbed the jar file from our Oracle installation directory. We have 11g installed. With 11g you should be able to find the file here:
$ORACLE_HOME/oc4j/lib/dms.jar
I got the same error for different reason and yes it was due to missing dms.jar file. I just had to find where dms.jar file was on our Oracle Application server (Release 12.2.3) and assigned it to the CLASSPATH. And it worked. Thanks for the pointing to the missing .jar file.
Out .jar file was in $ORACLE_HOME/lib/ folder. Changed the path value as :
CLASSPATH=$CLASSPATH:$ORACLE_HOME/lib/dms.jar and it started working.
Fyi..if it helps anyone i was trying to load BI/XML publisher DATA TEMPLATE using XDOLoader utility when i got this error.
-ppemavath
i too face this problem but when i removed all database related jars and added ojdbc6 (or ojdbc7) jar then application working fine. more details please see below link.
https://community.oracle.com/thread/2388722
Ok I am on Win Vista and correctly set my MAVEN_HOME, JAVA_HOME stuff. but I do not have a class path yet. I have also installed MySQL. now I have opened a Hibernate book and at the very first pages it says "make sure the jdbc driver is in your classpath" . I have also downloaded some Zip file that is ConnectorJ or some name like that which is basically the mySql driver for java... but my problem for now is this sentence that I have no clue how to do it: "make sure the jdbc driver is in your classpath"
would you please help me about this classpath thing?
thanks
Here is a good tutorial regarding, setting the class path. Further you might like to read Managing the Java classpath (Windows).
Having said that, you should not set the classpath for your driver in Windows environment variable. Instead, you should include that driver jar inside your IDE under project properties. But I noticed that you are actually using Maven. In this case you should look for the driver under Maven in order to fulfil that dependency. Maven will download the driver jar, if doesn't exist, and make it local.
In case, you are not using any IDE, then you can create a lib directory and tell the compiler that all required jars are in there, at the time of compilation/execution. You can find HOW, in the former link given above.
Since you are using Maven, you just need to put the JDBC driver as a dependency in your pom.xml file. Maven will add it to the classpath whenever it compiles/runs your application.
What you do when deploying your application is dependent on the technologies in use.
If it's a command line application create a %CLASSPATH% variable or add the path to the jdbc.jar file using the java -cp {path\to\jdbc.jar} option.
If it's a web application, you'll need to package the driver jar in your .war/.ear/.sar (the maven assembly plugin can do this) or include it in the ./lib folder of the application container and declare it as scope=provided in maven.
Steps to setup JDBC for Eclipse projects
Download JDBC zip archive from
https://dev.mysql.com/downloads/connector/j/5.0.html
Extract the file and copy the executable jar file to program files->Java->jdk->bin
Right click on the project and select Buildpath->Add external archives->(Jar file)
Compile the program
you can directly connect database by following steps:
1) download mysql-connector-java 5.0.8 and extract the files.
2) then place the folder in program files.
3) then simply add this library on your project by right clicking on it.
4) and here you go. Run your app with db connectivity.
I am new to creating Java web applications and came across this problem when trying to interact with my database (called ccdb) through my application:
java.sql.SQLException: No suitable driver found for jdbc:mysql://localhost/ccdb/
My application runs on JBoss and uses Hibernate to interact with the MySQL database. I have the MySQL Driver in lib\mysql-connector-java-5.1.6-bin.jar of my project and I have the .jar configured in Eclipse as a "Java EE Module Dependency" so that it gets copied over to web-inf\lib\ when I deploy it to JBoss through Eclipse. I double checked and the driver is definitely in the .war file with the project, so it should be findable, right?
My hibernate.cfg.xml contains this line which should point hibernate to the driver.
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
Does anyone know what I need to do to get this to work? Do I have to configure the MySQL database as a JBoss datasource for it to work?
Thanks in advance.
Edit: kauppi's solution works, but I would prefer to have it in lib\ with the other jars, and I'm really curious as to why it won't work that way. Any ideas...?
There might be a better way to do it but I have usually copied the MySQL connector JAR to jboss\server\default\lib (assuming that you are using the default config).
putting external libraries in the lib folder is a bad practice.
You need to edit the file:
server/${servername}/conf/jboss-service.xml
and add
<classpath codebase="${jboss.server.lib.url:lib}ext" archives="*"/>
rigth after
<classpath codebase="${jboss.server.lib.url:lib}" archives="*"/>
then create a directory named:
server/${servername}/lib/ext
and drop your external jars in there.