How should I add JAR libraries to a WAR project in Eclipse without facing java.lang.ClassNotFoundException or java.lang.NoClassDefFoundError?
The CLASSPATH environment variable does not seem to work. In some cases we add JAR files to the Build Path property of Eclipse project to make the code compile. We sometimes need to put JAR files inside /WEB-INF/lib folder of the Java EE web application to make the code to run on classes inside that JAR.
I do not exactly understand why CLASSPATH does not work and in which cases we should add JARs to Build Path and when exactly those JARs should be placed in /WEB-INF/lib.
The CLASSPATH environment variable is only used by the java.exe command and even then only when the command is invoked without any of the -cp, -classpath, -jar arguments. The CLASSPATH environment variable is ignored by IDEs like Eclipse, Netbeans and IDEA. See also java.lang.ClassNotFoundException in spite of using CLASSPATH environment variable.
The Build Path is only for libraries which are required to get the project's code to compile. Manually placing JAR in /WEB-INF/lib, or setting the Deployment Assembly, or letting an external build system like Maven place the <dependency> as JAR in /WEB-INF/lib of produced WAR during the build, is only for libraries which are required to get the code to deploy and run on the target environment too. Do note that you're not supposed to create subfolders in /WEB-INF/lib. The JARs have to be placed in the root.
Some libraries are already provided by the target JEE server or servletcontainer, such as JSP, Servlet, EL, etc. So you do not need put JARs of those libraries in /WEB-INF/lib. Moreover, it would only cause classloading trouble. It's sufficient to (indirectly) specify them in Build Path only. In Eclipse, you normally do that by setting the Targeted Runtime accordingly. It will automatically end up in Build Path. You do not need to manually add them to Build Path. See also How do I import the javax.servlet / jakarta.servlet API in my Eclipse project?
Other libraries, usually 3rd party ones like Apache Commons, JDBC drivers and JEE libraries which are not provided by the target servletcontainer (e.g. Tomcat doesn't support many JEE libraries out the box such as JSF, JSTL, CDI, JPA, EJB, etc), need to end up in /WEB-INF/lib. You can just copy and paste the physical JAR files in there. You do not necessarily need to specify it in Build Path. Only perhaps when you already have it as User Library, but you should then use Deployment assembly setting for this instead. See also ClassNotFoundException when using User Libraries in Eclipse build path.
In case you're using Maven, then you need to make absolutely sure that you mark libraries as <scope>provided</scope> if those are already provided by the target runtime, such as JEE, Servlet, EL, etc in case you deploy to WildFly, TomEE, etc. This way they won't end up in /WEB-INF/lib of produced WAR (and potentially cause conflicts with server-bundled libraries), but they will end up in Eclipse's Build Path (and get the project's code to compile). See also How to properly install and configure JSF libraries via Maven?
Those JARs in the build path are referenced for the build (compile) process only. If you export your Web Application they are not included in the final WAR (give it a try).
If you need the JARs at runtime you must place them in WEB-INF/lib or the server classpath. Placing your JARs in the server classpath does only make sense if several WARs share a common code base and have the need to access shared objects (e.g. a Singleton).
If you are using Maven:
Open the project properties, and under Deployment Assembly click Add...
Then select Java Build Path Entries and select Maven Dependencies
Resolved by setting permissions.
Had related issue using PySpark and Oracle jdbc. The error does not state that the file cannot be accessed, just that the class cannot be loaded.
So if anyone still struggles, check the permissions. Some might find it obvious tho'.
I want to give the answer for the folowing link question ClassNotFoundException oracle.jdbc.driver.OracleDriver only in servlet, using Eclipse
Ans: In Myeclipse go to Server-->left click on Myeclipse Tomcat7-->Configure Server Connector-->(Expand)Myeclipse Tomcat7--> Paths-->Prepend to classpath-->Add jar (add oracle14 jar)-->ok
I would like to understand what role the target folder plays in a SOA MDS project.
I am using JDeveloper and the target folder keeps getting populated with 2 .jar files. I am not sure where these jar files are coming from, but they contain old data which should be changed.
Can somebody please help me understand what is behind the making of these files?
The target folder is the default build output directory used by maven.
If working correctly, the builds should be generated there by maven using the configuration specified in the pom.xml file. In your case, the maven build might not have been run recently, which is why you see old content in the jars.
Have a look inside the pom.xml and see what build configuration has been specified there (it is likely to be no different from a SOA composite maven build file/pom file). If it's all built correctly, you should be able to deploy that jar directly to the MDS runtime (either manually or via maven).
In the pom file, you should be able to override most things there including the name, version, bundle type, target directory etc.
You can also use maven to keep track of your MDS changes - i.e. version it like any other build artifact/SOA composite. The versioned jars can also be uploaded to an artifact repository (such as nexus), in addition to being deployed to MDS runtime, so you have good level of traceability of MDS changes
PS -
This might help explain more: http://weblog.singhpora.com/2016/10/managing-shared-metadata-mds-in-ci.html
I have created a multi module project in Alfresco using All-in-one Archetype of the Maven Alfresco SDK. I have selected 1.1.1 archetype version. The project directory was build successfully. But in that directory I couldnt find the wcmqs(Alfresco Web Quick Start) directory which is used to build websites. Can anyone help me hw to get this wcmqs, as I need to work with wcmqs for creating new pages and templetes in wcmqs?
The wcmqs module did used to be in the Maven Alfresco SDK but it never worked very well and caused other problems. It is however unnecessary to use the Maven Alfresco SDK if you wish to get started.
To get started with Alfresco Web Quick Start you just need to download and install the files. You can get the files from Sourceforge: http://sourceforge.net/projects/alfresco/files/Alfresco%204.2.f%20Community/
Installation should be straightforward. You need to install the AMPs on your Alfresco instance and deploy the WARs to a servlet container (like your Tomcat).
If you want to customise Web Quick Start, such as changing the model, that is a different matter. There is a short example here that you can go through to give you an idea of what you need to do:
http://ecmarchitect.com/archives/2011/01/06/1254
I keep seeing sbt projects with the following resolvers setting in their build definition:
resolvers += "Local Maven Repository" at "file://"+Path.userHome.absolutePath+"/.m2/repository"
It's also described in the official documentation of sbt in Resolvers section.
My limited knowledge of using sbt and build management tools in general lets me however consider it as a kind of anti-pattern.
The reason is that if a project declares a dependency on a library in the Local Maven Repository it somehow got downloaded there in the first place so it's available somewhere outside the local maven repository. If it is, why not using the original repository as the source?
If the dependency is not in a public repository, and is a dependency of a project, the project can use dependsOn to declare it without the additional repository in resolvers.
Please advice as I may be missing something obvious that makes the resolvers setting indispensable.
One obvious reason would be if one of your dependencies is a local project built with maven.
One scenario:
You have a project x which you build with sbt
X depends on y. Y is built with maven.
There is a bug in y which you need to fix/test, and you want to regression test x before you check it in.
You build a snapshot of y, and then you can test x before you commit the change to y.
I've created a maven project from a spring-ws example and imported into STS (by using mvn eclipse:eclipse and importing it). It comes with a war file, which I'd like to deploy to the server, from STS or otherwise. Any idea how to do this?
My suggestion would be as follows:
remove your project from STS
run mvn eclipse:clean on the command line
import the mavan project into STS as a maven project and use m2eclipse
Open the servers view
Drag and drop the project onto the server
This should be sufficient for deploying onto tcServer. You may be able to skip steps 1-3, but I am not sure if your maven generated .project file will be sufficient for WTP to know that the project can be run on tcServer. Worth a try, but I think you'll have to do the full 5 steps.