Errors when import existent maven project into eclipse kepler - maven

I have imported a existent maven project (swagger for jersey jax-rs) into eclipse.
I get a bunch of errors:
It always has to do with the jackson-databind.jar
Example error:
Archive for required library: '.../.m2/repository/com/fasterxml/jackson/core/jackson-databind/2.1.5/jackson-databind-2.1.5.jar' in project 'swagger-core_2.9.1' cannot be read or is not a valid ZIP file
I cannot find the .m2 folder? I am new to the maven stuff,
do i have to install something extra before i import a maven project into eclipse?
Thx

I cannot find the .m2 folder?
By default the .m2 directory is located at the home directory.
For *Unix operating systems, it will be something like /home/<user_who_fires_maven_commands>/.m2/...
For Windows machines , the m2 will be located at C:\Users\<user>\.m2\...
As for the exception you are getting
Archive for required library: '.../.m2/repository/com/fasterxml/jackson/core/jackson-databind/2.1.5/jackson-databind-2.1.5.jar' in project 'swagger-core_2.9.1' cannot be read or is not a valid ZIP file
It is most probable that the archive file has gotten curropted ( maybe a download issue or might be possible that its sha1 doesn't match with the one that is on the central repo ). So you can try by simply deleting this jar file and then run mvn install and it will re-attempt to download the file again.
Another thing I would like to point out is that since this is a new eclipse installation, I would suggest that you re-index your local m2 folder so that this new eclipse knows about the files and folders inside the original m2 folder. To re-index, goto Window -> preferences --> Maven --> User settings --> there will be a text field stating the path of the .m2 ( make sure its correct ) and then press re-index

Related

Where m2 file is stored when installing apache maven on a unix box

I downloaded maven gz file, unzipped same, but i dont know where the m2 is stored. I imagine im missing a step but i cant see what one?
Is there aninstall script etc?
[root#atddpvm5 apache-maven-3.5.4]# cd /var/tmp/apache-maven-3.5.4/
[root#atddpvm5 apache-maven-3.5.4]# ls
apache-maven DEPENDENCIES doap_Maven.rdf LICENSE maven-builder-
support maven-core maven-model maven-plugin-api
maven-resolver-provider maven-settings-builder NOTICE README.md
CONTRIBUTING.md deploySite.sh Jenkinsfile maven-artifact maven-compat
maven-embedder maven-model-builder maven-repository-metadata maven-
settings maven-slf4j-provider pom.xml src
By default the .m2 folder is stored in the home folder of the user. In this case since you are using root, the path is most likely /root/.m2. You also have to use the -a switch with ls to see that folder, since it's a hidden folder (it starts with a .). Note that the folder will only be created on the first usage of Maven, i.e. when you call a maven command on a maven project, like mvn clean install.
Additionally it looks like you have downloaded the source distribution of Maven, which only makes sense if you want to work on Maven itself. You might want to download the binary distribution, if you just want to use it.

Moving gradle build to another machine

It seems that when Gradle 3.1 downloads the dependencies for your project it stores them in:
C:\Users\username\.gradle\caches
I tried copying the contents of this folder to a different machine that has a fresh Gradle 3.1 installation, but when I try to build my project it still tries to download all of the dependencies from scratch, which then fails because the new machine has no internet connection.
How do I get around this?
Compress main folder C:\Users\username.gradle to gradleHome.zip
Copy and uncompress this gradleHome.zip file to another folder for example D:\gradle_home
set gradle_home environment variable to this new folder. See how to change environment variables in windows here.enter link description here

Maven - Wrong folder structure

I have checked in one of my projects to GIT repo. When i cloned it from GIT, imported the project to eclipse and converted the project to Maven Project, the folder structure of maven seems to be a bit different
This should have been src/main/java, src/test/java, src/test/respurces folder structures and com.vod... as package.
I have tried maven>update project, project>clean, maven>clean, eclipse::clean, eclipse::eclipse. But this project structure does not seem to go off.
Any possible solutions for this please?
After importing the project as eclipse general project, below is the structure.
This is a typical problem due to the lack of Eclipse metadata files in the GIT repository.
How to solve it:
Open the project's contextual menu > Java Build Path > Configure Build Path > Source. Drop off folder src and set as folder sources just these:
src\main\java
src\main\resources
src\test\java
src\test\resources
This will save some metadata to the .classpath file.
Also, you should ensure that this was set as a Maven project: Open the project's contextual menu > Configure. If there is the Convert to Maven command, execute it (if not, it is already a Maven project). This might save some metadata to the .project file.
Then, be sure to check in the Eclipse metadata files (.classpath, .project and .settings folder) to GIT. And, in order for this project can be safely shared to other developers, be sure not to enter absolute paths in the java build path, nor other system-dependant constraints.

dist and native-win could not be activated, no POM in directory

Please explain what is required to be done stepwise.
How to activate -dist and native-win?
I saw your error contains there is no pom in this directory.
Maven can run only from the location where pom file exists so make sure pom file is there in your project.
For example, your project is inside C:\Users\HP then so maven will consider HP as a project and it will try to find pom file inside HP project.
This error is coming because you didnot place hadoop source package in the C:/User/HP directory. you can download appropriate source package from http://www.apache.org/dist/hadoop/core/
unzip it and place all the files & folder in C:/User/HP then run your maven package command. It should work

Managing external JARs build paths in git controlled eclipse project created in Ubuntu and cloned in Windows

I am having an eclipse project created on Ubuntu, in which all the JARs that I am using, are located in a folder /home/xyz/AllJARs. Here the /home is the system home folder. The project as well as the AllJARs folder is git version controlled on a central git server.
So, all the paths to these JARs in the project's build path are /home/xyz/AllJARs. When I'm cloning the project repo and the AllJARs repo on a Windows machine, I'm shown errors related to build path since it can't find the path /home/xyz/AllJARs.
How can I manage this situation where I can have external JAR files in build paths which can work on Ubuntu as well as on a Windows machine? Thanks in advance.
You have two easy options:
use relative paths: for example, put the JAR folder in the folder above your project, then you can set the JARs' paths to ../AllJARs/
put JARs into project: you can also just put the JARs into the project folder; if you've set them up as "External JARs" in project settings, you'll have to remove them from that list, and re-add them with "Add JARs". Eclipse will then look for them locally in the project folder. If you don't want to commit the JARs to the git repo (size and/or permission being a problem), you can just copy them into the Project folder after cloning. While they're not there, you'll be shown a warning, but once Eclipse can find them, everything's fine.

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