I am new to Maven Project. I am making changes to one of the open source maven project. I am facing a problem in adding a library to the project. So far i have done this :-
I added a library named jni4net.j-0.8.8.0.jar to the resources folder of the project.
I right clicked the jar(in Intellij) and clicked 'Add as library'.
Then in the pom.xml i added:-
<dependency>
<groupId>jar.0.8.8.0.jni4net</groupId>
<artifactId>jar.0.8.8.0.jni4net</artifactId>
<version>0.8.8.0</version>
<scope>system</scope>
<systemPath>${basedir}/src/main/resources/jni4net.j-
0.8.8.0.jar</systemPath>
</dependency>
But when i build this project(build is successful, test cases are running) and use this it throws following error:-
java.lang.NoClassDefFoundError: net/sf/jni4net/Bridge
Please help me resolve it. I am new to maven and pom. I have looked at various answers, but not getting it right.
PS - I named groupId and artifactID as just reverse of jar file
This is not the right way to add that dependency.
All you need is:
<dependency>
<groupId>net.sf.jni4net</groupId>
<artifactId>jni4net.j</artifactId>
<version>0.8.8.0</version>
</dependency>
The dependency will be retrieved from Maven Central when you build.
Using <systemPath>...</systemPath> is highly discouraged as it usually ties your project to a local environment.
Since jni4net.j dependency is available in maven central, You don't have to download and put the dependency manually. Maven will download and store the dependency locally in `'.m2' folder. Just add dependency as bellow.
<dependency>
<groupId>net.sf.jni4net</groupId>
<artifactId>jni4net.j</artifactId>
<version>0.8.8.0</version>
</dependency>
Related
I'm trying to add Stanford CoreNLP 3.9.2 as dependency to my Eclipse/Maven project:
<dependency>
<groupId>edu.stanford.nlp</groupId>
<artifactId>stanford-corenlp</artifactId>
<version>3.9.2</version>
</dependency>
Next to my POM.xml file I see a little red x icon. When I open POM.xml there is no additional information regarding the error.
When I click on Java -> Properties -> Java Build Path -> Maven Dependencies I see that the Jars that were expected to be added to Maven via this dependency are missing. This is odd because I regularly add dependencies this way without any error.
Apparently, something is preventing Maven from downloading the dependencies. What could it be?
Update:
I changed POM file to version 3.5.2 (instead of 3.9.2) and now all errors are gone.
If anyone can explain WHY this solved my problem (and how to make things work with version 3.9.2) I will accept it as the answer.
Update:
When I go to my Maven repository I see that most of the required Jars have been downloaded by Maven. For example, Maven repository will contain the folders: \\maven\.m2\repository\edu\stanford\nlp\stanford-corenlp\3.9.2 However the folder will not contain the Jar: stanford-corenlp-3.9.2 - but it will contain every other Jar such as stanford-corenlp-3.9.2-models and stanford-corenlp-3.9.2-sources etc.
This makes the whole situation even more confusing. If Maven is downloading the Jars why is it skipping just one Jar? I looked in several other folders (dependencies of corenlp) and I see similar phenomenon - it's always the main Jar of that folder that is missing.
What's worse, when I download and add the missing Jars manually to Maven folder, the (missing) text next to Jar goes away but there's still a little red x icon next to POM file. I have no idea what is going on.
Any insights?
Thanks!
I have no idea why this fixed the problem but in my POM file I had an entry:
<dependency>
<groupId>org.eclipse.platform</groupId>
<artifactId>org.eclipse.debug.core</artifactId>
<version>3.13.0</version>
</dependency>
I update this dependency to:
<dependency>
<groupId>org.eclipse.platform</groupId>
<artifactId>org.eclipse.debug.core</artifactId>
<version>3.14.0</version>
</dependency>
Now all errors have disappeared.
I am working with a maven project in eclipse which I have been testing using the built-in "run on server" tomcat option. When I try to do this, I get errors stating certain dependencies are unmet from an external jar I reference in the POM. However I have found if I add the jar via the DeploymentAssembly Tab I can run in eclipse without issues:
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'com.company.user.server.UserDetailsAuthoritiesMapper#0'
The issue comes when I try to deploy on an actual tomcat instance. The Maven build runs fine, but when I start the servlet I get the same unmet dependency errors. This to me is indicating that the external jar is not being properly packaged into the war. What is the maven equivalent of adding the package via the DeploymentAssembly tab in eclipse? The entry in the POM.xml:
<dependency>
<groupId>com.company.webapp</groupId>
<artifactId>webapp-user</artifactId>
<version>106</version>
</dependency>
Thanks
You need to locate the maven info for the external jar. If you google the name of the jar and maven you often find a direct link to the block you need. For example if I want version 1.58 of the Bouncy castle jar Google "Maven BouncyCastle" you can find the artifact info. Add that info to your pom.xml as a new dependency in your block.
<!-- https://mvnrepository.com/artifact/org.bouncycastle/bcprov-jdk15on -->
<dependency>
<groupId>org.bouncycastle</groupId>
<artifactId>bcprov-jdk15on</artifactId>
<version>1.58</version>
</dependency>
After you rebuild, refresh maven in your IDE 1st after doing a clean, this will tell maven to pull down the jar and added it to your build.
You can also go to the repo directly and search:
Maven Repo: https://mvnrepository.com/
I'm currently learning java and want to create a project, using maven, hibernate and MySQL. I know that in order to use any of the artifacts with maven, I should find it on mvnrepository and add it to pom.xml. The question is where can I get the list of mandatory dependencies for each artifact I use, f.ex if I need hibernate, I found hibernate-core 4.3.8.Final, proceed to this link and can see it's dependencies in section "depends on". Should I add all of them into pom.xml also?
Well, I think you know about maven.
And yes, You should include all the dependencies with version on your pom.xml files (Which is the main file for all your dependencies ).
First, you need to identify all required dependencies and add on pom file.
While executing code, It primarily tries to get that dependency from local repository (.m2) And if it doesn't exists then it downloads from it's web repository.
Link: maven setup
How it works??
Suppose, You are using log4j for loggin.
You need to know the log4j Maven coordinates,
for example
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.14</version>
It will download the log4j version 1.2.14 library automatically. If the “version” tag is ignored, it will upgrade the library automatically when there is a newer version.
Declares Maven coordinates into pom.xml file.
<dependencies>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.14</version>
</dependency>
</dependencies>
When Maven is compiling or building, the log4j jar will be downloaded automatically and put it into your Maven local repository.
All manages by Maven.
How to find the Maven coordinates?
Visit this Maven center repository, search the jar you want to download.
Hope, It will help.
Thanks.
I have a proprietary library. I am using this library in my java desktop project but now, I have a maven project. I want to add this library in my maven project with dependency. How can I do this?
Firstly you should search if this library is available as maven dependency. Try maven search.
For example if you want to include a library commons-io-2.4.jar, you serach for it in the link above, if it is in public repository (it is), then you get maven dependency:
<dependency>
<groupId>commons-io</groupId>
<artifactId>commons-io</artifactId>
<version>2.4</version>
</dependency>
You should paste this dependency to your pom to dependencies tag.
If above library is not available in public repository, you have to place your jar manually in your local repository by refering to: http://maven.apache.org/guides/mini/guide-3rd-party-jars-local.html
Example:
mvn install:install-file -DgroupId=commons-io -DartifactId=commons-io -Dpackaging=jar -Dversion=2.4 -Dfile=home_folder_path/commons-io-2.4.jar -DgeneratePom=true
If it is not already on maven repository, simply add it to your pom.xml, and add it to your local repository.
<dependencies>
<dependency>
<groupId>com.proppath</groupId>
<artifactId>mylib.jar</artifactId>
<version>myjarversion</version>
</dependency>
And also put this prop library into
.m2\repository\com\proppath\myjarversion
Give any groupId you like but make sure that you have corresponding path on repository to find it.
Normally, in large projets these kind of propriatery libraries are stored in Nexus of your enterprise.
I try to compile this pom file but it doesn't download
import org.codehaus.swizzle.confluence.*;
dependency. I get pom file from maven's site. Search Maven Swizzle
That's the POM of the swizzle-confluence library, i.e. the POM file that the library's project uses for its own build.
Instead, you need to add the dependency declaration for this library to your project's POM. In Maven Central search, this is available on the left-hand-side of the version information page, under Dependency Information.
So, open up the page for swizzle-conflunce:1.6.2, and you can see that this is:
<dependency>
<groupId>org.codehaus.swizzle</groupId>
<artifactId>swizzle-confluence</artifactId>
<version>1.6.2</version>
</dependency>
Also, to help yourself in the future, consider reading about the POM and how dependencies work.