Develop Reference

Java and intelij idea [duplicate]

I just imported a project from subversion to IntelliJ IDEA 11 - it's a maven project. But I have a problem in maven library dependencies so that I can't include all maven dependencies automatically - IDEA shows dependency errors only when I open that class/ Thats what I get here:
So I want all dependencies to be added automatically - is that possible or do I have to go through all class files to identify and add maven dependencies?!
UPDATE: After doing some modifications I found how to resolve my problem in some way. Thats what I did:
but I think logically it will not include and check new dependencies ahead?!... Is there any settings area for this in intelliJ - auto export dependencies to classpath?

IntelliJ should download and add all your dependencies to the project's classpath automatically as long as your POM is compliant and all the dependencies are available.
When importing Maven projects into IntelliJ an information box usually comes up asking you if you want to configure Auto-Import for Maven projects. That means that if you make any changes to your POM those changes will be loaded automatically.
You can enable such feature going to File > Settings > Maven > Importing, there is a checkbox that says "Import Maven projects automatically".
If that doesn't help, then I would suggest to make a full clean-up and start again:
Close your project window (and IntelliJ) and remove all *.iml files and all .idea folders (there should be one per module)
Run mvn clean install from the command line
Re-import the project into IntelliJ and pay attention when it asks you to enable auto-import
IntelliJ 2016 Update:
The Import Maven Projects automatically setting has been moved to Build, Execution, Deployment > Build Tools > Maven > Importing in your IntelliJ preferences.

Fix before IntelliJ 14
File [menu] -> Settings -> maven -> importing and uncheck "use maven3 to import project"
ref: http://youtrack.jetbrains.com/issue/IDEA-98425 (which may have a few other ideas too)
Fix IntelliJ 15+
Ran into this again, with IntelliJ 15 this time, which has no "use maven3 to import" option available anymore. The cause was that sometimes IntelliJ "doesn't parse maven dependencies right" and if it can't parse one of them right, it gives up on all of them, apparently. You can tell if this is the case by opening the maven projects tool window (View menu -> Tool Windows -> Maven Projects). Then expand one of your maven projects and its dependencies. If the dependencies are all underlined in red, "Houston, we have a problem".
You can actually see the real failure by mousing over the project name itself.
In my instance it said "Problems: No versions available for XXX" or "Failed to read descriptor for artifact org.xy.z" ref: https://youtrack.jetbrains.com/issue/IDEA-128846
and
https://youtrack.jetbrains.com/issue/IDEA-152555
It seems in this case I was dealing with a jar that didn't have an associated pom file (in our maven nexus repo, and also my local repository). If this is also your problem, "urrent work around: if you do not actually need to use classes from that jar in your own code (for instance a transitive maven dependency only), you can actually get away with commenting it out from the pom (temporarily), maven project reload, and then uncomment it. Somehow after that point IntelliJ "remembers" its old working dependencies. Adding a maven transitive exclude temporarily might also do it, if you're running into it from transitive chain of dependencies."
Another thing that might help is to use a "newer version" of maven than the bundled 3.0.5.
In order to set it up to use this as the default, close all your intellij windows, then open preferences -> build, execution and deployment -> build tools -> maven, and change the maven home directory, it should say "For default project" at the top when you adjust this, though you can adjust it for a particular project as well, as long as you "re import" after adjusting it.
Clear Caches
Deleting your intellij cache folders (windows: HOMEPATH/.{IntellijIdea,IdeaC}XXX linux ~/.IdeaIC15) and/or uninstalling and reinstalling IntelliJ itself. This can also be done by going to File [menu] -> Invalidate Caches / Restart.... Click invalidate and restart. This will reindex your whole project and solve many hard-to-trace issues with IntelliJ.

When importing the project, select pom.xml instead of the project directory. It should work.

Try to Re-Import the project from the Maven Projects panel in IntelliJ IDEA. It should download and configure all the dependencies defined in your pom.xml automatically.
If download doesn't work from IDEA for some reason, try mvn install from the command line and see if the dependencies can be fetched.
Of course all the required dependencies and any custom repositories must be defined directly in the pom.xml file.

For IntelliJ 2016-2.4 (and I believe other new-ish versions):
View > Tool Windows > Maven Projects
In the newly revealed toolbar, select Maven settings (icon of a toolset).
When this screen opens, expand the Maven menu and click 'Importing'
Here, click "Import Maven projects automatically." Also ensure that the 'JDK for Importer' option matches the JDK version you mean to use.
Click OK. Now go to the red dependency in your pom.xml, select the red lightbulb, and click 'Update Maven indices'.

What helped me:
Navigage:
Settings | Build, Execution, Deployment | Maven
Specify "Maven home directory" - the place you installed the maven

If certain maven modules are not compiling check if their pom.xml is on the "ignored files" list. In IntelliJ goto
preferences -> project settings -> maven -> ignored files
and check if the related pom.xml is ignored.

I had the same issue and tried all the answers mentioned here, none worked.
The simple solution is go to your project folder and delete all the .idea and .iml files and restart the IntelliJ ide. It works. No need to do anything with the settings.

Open IntelliJ Idea, Go to
File > Other Settings > Default Settings... > Maven (Preferences) > Importing or|
Preferences > Maven > Importing
Click on Enable Auto-import in the console.

When you create a new project you simply need to choose the option:
...
Import project from external model
Create IDEA project structure over existing external model (Eclipse, Maven...)
...
You'll find it pretty straight forward from there.
And in your case you can close your project and simply create a new one. Choose your project's directory, which will override it, making it a Maven project.

Importing Maven dependencies may not work if you import the same path several times. This may happen automatically after importing an existing maven project. I can't figure out why this happens, so I'm inclined to think it is a bug.
For example, if my project is
hibernate
src/main
src/test
the three paths may be imported as top nodes:
hibernate
src/main
src/test
If such is the case, the dependencies appear to be right, but they won't be used until you remove the superfluous paths (in this case, src/main and src/test). Once you do this, refresh and click Build > Rebuild Project. IDEA will pick up the dependencies.
A symptom of this problem is that IDEA warns you of a duplicated path when you manually check a library (second screenshot in the question).
There are several ways to re-read the dependencies in case you need it. If you go to the “Maven Projects” tab, there is a “Reimport All Maven Projects” icon at the top left of the tab. If you suspect IDEA became confused you can click on File > Invalidate Caches.

First check path Specified for User Settings file: in Settings -> Build,Execution,Development -> Build Tools -> Maven .
The field should have path of the settings.xml of your maven. Also the settings.xml should have correct path of remote repository.

Go into your project structure, under project Settings, Modules, select the dependencies table. For each dependency, change the scope from 'Test' to 'Compile'.

If in the lower right corner it says "2 processes running..." or similar, you may just need to wait for that to finish, since it may take time to download all the jars.

Reimport the project. If you install maven plugin you can use this.
Right click on the project -> Maven -> Reimport

I had a similar issue, in my case I am using a custom settings.xml which was not picked from IntelliJ.
Solution:
File > Settings > Build, Execution, Deployment > Maven: User settings file (chose here my custom settings.xml).

IntelliJ 2020.3.3
This one did it for me.
Build, Execution, Deployment > Build Tools.
Change "Reload project after changes in the build scripts":
from default "External Changes" to "Any Changes"
With this, it took a while for the project to rebuild but now I can see Maven dependencies in IntelliJ:

I ran into the problem that some subdependencies couldn't be resolved in IntelliJ 2016.3.X. This could be fixed by changing the Maven home directory in Settings > Build, Execution, Deployment > Build Tools > Maven from Bundled (Maven 3) to /usr/share/maven.
After that all subdependencies got resolved as in previous IntelliJ versions.

In my case, path for JAVA used by MAVEN was not set as JAVA_HOME as configured on the machine. Hence, it was not even trying to download the dependencies.
Steps I followed which solved this issue,
Checked for JAVA path , Settings >> Build >> Build Tools >> Importing >> JDK for importer. Pointed it to JAVA_HOME.
mvn clean install -U
Used above command to force the dependencies download.
Re imported Maven Projects

So I was also facing this problem in lots of my organisation's codebase. On addition to the answers suggested above, we can tweak around with the allocation pool memory of the jvm. This is because, the volume of the dependencies brought in large codebases may be overwhelming for the jvm for IDE to build the project completely. Hence tried increasing XMX value and it worked! Added -Xmx3072 to resolve the issue of "not building" my Java project in IntelliJ

Maven - Reimport did not work for me.
I have Spring project in STS(Eclipse) and my solution is to import project to IDEA like so:
1) File - New - Project from Existing Sources... - select directory - choose Eclipse.
2) Set Maven autoimport to true in settings.
3) Then right click in pom.xml and choose Add as Maven Project.
After this it has imported everything.

I had the similar issue with my macbook, just did a small change in pom.xml and it started downloading all dependencies:
Earlier dependencies were written as below for my windows machine:
<dependencies>
<dependency>
<groupId>javax.mail</groupId>
<artifactId>mail</artifactId>
<version>1.4</version>
</dependency>
</dependencies>
I just removed the <dependencies> and </dependencies> tags and it started downloading all the dependencies:
<dependency>
<groupId>javax.mail</groupId>
<artifactId>mail</artifactId>
<version>1.4</version>
</dependency>
I am not sure it will work for you or not.. but worked fine for me.
Thanks

Deleting the .idea folder from the project directory, and then re-importing the project as a Maven project is what worked for me.

Invalidate Caches worked for me:
File > Invalidate Caches
Checks:
Clear file system cache and Local History
Clear downloaded shared indexes
Then Invalidate and Restart

I solved this issue by updating my settings.xml file with correct mirror config, seems that intellij will try to download meta-data from repository every time the maven module imported.

Hijacking a bit to add what ended up working for me:
Go into the Maven Projects sidebar on the right edge of the IDE, and verify that your dependencies are listed correctly under your module there. Assuming they are, just ask IDEA to reimport then (the first button at the top, looks like two blue arrows forming a counter-clockwise circle).
Once I did that, and let IDEA reload the project for me, all my dependencies were magically understood.
For reference: this was with IDEA 13.1.2

I faced the same problem and tried everything suggested which did not solve the issue, I was using Intellij version 13.1.3
Finally after spending more than couple of hours trying to fix it, I decided to try an upgraded version and opened the project in version 14.1.4 which ultimately resolved the issue. I would think this as a probable bug in the previous version.
I hope this helps!

I was able to resolve it by removing unnecessary modules from Project Settings -> Modules list.
It turns out these additional modules were created automatically by IntelliJ IDEA when I created the IntelliJ project by importing from the project folder (instead of by opening pom.xml). Then, after declaring the project as Maven project, proper modules were created, and existing modules were conflicting with them. It is also possible to exclude those modules during project creation.

In my case, one of the modules was ignored for some reason.
To resolve that: Right click the problematic module and choose "Unignore Projects".

You might be working under a company's internal network.
If so, to download or add external Maven dependencies your settings.xml file under user/<username>/.m2 folder might need to be updated.
Contact your administrator to provide the right settings.xml file and then paste it into you .m2 folder.

Error Could not find or load main class springboot eclipse

I can run my first project created correctly (springboot, eclipse), but when I run any of the other projects, the following errors are shown:
The problem is occurs when I create projects using Spring Boot v2.3.4, but when I use version 2.1.17, projects are built correctly --- obviously it must be a compatibility issue.

Soln 1.
You can try updating maven project.
Right Click the project -> Maven -> Update Project.
Then do maven clean install
OR
Soln 2.
From the image it can be seen that it says "it cannot be read or is not a valid zip file". So for all such jar file go to the respective location in .m2 and delete such jar files. Then
Right Click the project -> Maven -> Update Project.
Then do maven clean install

Problems with IntelliJ at cloning repo from github

I am new to github. I tried to clone a repo and then pull the files on my computer. All the other team members did the same thing and it worked for them. When i open the project with Intellij all the .java files look like this:
files
It also says that my SDK isn't set.
I tried to set my SDK, and also i tried to set the java directory as 'sources root' because someone said that is a problem with the project structure.
These problems disappeared but then IntelliJ didn't recognize that my project is a maven project so i had to add manually the file pom.xml and refresh maven.
Then this problem disappeared but i had another:
"Cannot start compilation: the output path is not specified for module 'cmsiss'.
Specify the output path in Configure Project."
I tried to set it from project structure but now I have this error:output error
Please help.

Open maven project using pom.xml file. File->Open->pom.xml
Sources should be pointed to project root, not java directory.
Give these a try.

The usual steps that I follow to open the project:
git clone <github clone url>
Open the project in intelli J using
File<Open
and browse to open the root of the project.
This should work fine but if it does not, a few more things you can try:
Try making the project root as a maven module
You can open the Project Structure to make sure you have Java SDK set up properly. It should show the java version you are using there.
Worst case, that is if nothing else works and if the project is not too big, just create a new maven project and make sure it runs, then add all the project files.

I pulled the project again and started from zero. I specified the SDK and then I opened the Maven project window and added a maven project (selected the pom.xml file) and refreshed it. Maven did it's job and created the project structure and all the stuff I've tried to do manually and finally worked!

imported maven project does not appear as java project. Shows folders

I checked out the existing project source code from SVN to a folder in my system.
Then I opened eclipse. Import Project-> Existing Maven Project.
It imported without issues. However, Project Explorer shows it as just folders instead of packages. (Like when we create a package and then add classes to it, it shows a different icon for package root). I opened Navigator and Package Explorer as well. But they are showing them as folders as well.
I tried:
mvn eclipse:clean
mvn eclipse:eclipse
on the root of the project. But it did not help.
Can anyone help on this one?
My folder structure:
ecs->
ecs-ejb->
src/java/main/com/xxx
pom.xml
ecs->ear->
src/java/main/com/xxx
pom.xml
pom.xml

Try to:
Right click the project->Configure->Convert to Maven Project
---- Edit ----
If this doesnt work, it is likely that someone checked in their environment files into your SVN. If they checked in:
.project
.classpath
.settings/
They could be conflicting with your environment (different settings/plugins/versions of eclipse...). Try dropping your project, deleting the folder/files, then remove these files from SVN, and repeat your initial process. All of these files/folders will get generated during the import to eclipse.
---- Edit 2 ----
Per your recent edit to the question, you have a multi-module project. If you only did this on the parent project, then there is no source folder. So you wouldn't see it. You should:
File->Import...
Choose Existing Maven Projects, Next
Set the Root Directory to ecs/ecs-ejb, Finish
Repeat for all other modules.
In eclipse, each module of a multi-module maven project needs its own eclipse project.

Right click the project->Configure->Convert to Faceted Form
This solution worked for me

Possibility is Module doesn't have .classpath.
Kindly right click on Module and Change Project fact as Java.
else
If you are using command Prompt.
1. mvn eclipse:clean
2. mvn eclipse:eclipse
else
Delete Project from Eclipse don't delete content from disk. remove .classpath and .project
Re-import as maven existing Project

Right Click->Maven->Update Project.
Above works perfectly fine for Eclipse Juno and solves the problem.

You just need to change the nature of the project.
For MAC->
-> Right click on project
-> Properties -> Check Project Natures
-> Then add or remove accordingly if you are having a maven project then add Maven, add Java

I had the same problem. I tried a lot of things that I read on internet but the only way that I found to solve my problem was exclude all of my workspace files (.metadata folder) and create another one.
After that, I imported a existing maven project and all my problems are gone.

I also faced a similar issue. I resolved it by downloading the correct apache maven plugins in the maven repository org / apache/ Maven/ plugins. IN my case, everything was working fine earlier and I had deleted .m2 repository completely. After that I started getting these issues with same iDE and newer IDE versions as well. The pom.xml showed error related to lifecycle mappings. On downloading the correct plugin, the workspace worked fine.

Delete the metadata folder. Checkout again but select "Checkout as a project configured using the New Project Wizard" instead of "Checkout as a project in the workspace".
Then a New Project wizard will open, type maven there and select "Checkout Maven Projects from SCM" preferably or "Maven Project". It should work. Remember this step should be performed for Maven Projects only. For normal Projects just select Java Project or whatever relevant type Eclipse project it is.

Check and make sure you have eclipse pointing at a Java JDK directory instead of a Java JRE directory.
I had just installed eclipse and only the JRE was in the settings. I added the JDK path, changed it to the default and clicked on Maven -> Update project. Then the packages appeared in Package Explorer.
The hint that helped me figure this out is that when I tried to use the refactor to rename a class, it wouldn't do it, complaining that it wasn't a JDK.

Instead of importing as Existing Maven Project, follow below steps
I assume that your folder has pom.xml, src/main and src/test.
Step 1: Right click > Create New > Java Project > Chose the project folder has pom.xml
Step 2: Right Click on Project > Configure > Convert to Maven project

I got it working using Proyect --> Properties --> Project Facets
In my case was a web project so I checked Java and Dynamic Web Module

Try right click on project, Maven->Update Project... (or similar, the link name changes depending on version)
This works for me when adding new folders, but I have not encountered the problem when importing a project.

Right click the project, then click Configure -> Convert to Maven Project. If the packages still display as ordinary folders, then right click on the folder one level up (the one that is supposed to be the source folder), then click Build Path -> Use as a source folder.

Here is my solution please close the Project Explorer at the left top and open again.
(or)
1). Right Click on your miscellaneous project and choose project Explorer if available.

Adding projects to working sets should help
try it ->
right click the project -> Maven -> Assign Working Sets... -> Add projects to working sets

Compiler error "archive for required library could not be read" - Spring Tool Suite

I am starting to configure my development environment and I am using Spring Tool Suite 2.8.1 along with m2E 1.01.
As far as I can tell, since this is a Maven Project (my first), my Maven POM is dictating (along with m2E smarts) my project build configuration and dependencies.
What I would like to know is why my IDE is displaying Java Build Problems that read "Archive required for library library/path/somejar.jar cannot be read or is not a valid zip file" when I can see the jars in my .m2 repository?
All the errors pertained to commons-logging:1.1.1 which I excluded in my parent-pom. This was a transistive dependancy via spring-context-support:3.0.5. I excluded that library from my build and now the errors pertain to the spring-context-support library.
I have attached a screenshot to illustrate.

Indeed IDEs often cache the local repository (Eclipse does something similar, and I have to relaunch Eclipse).
One ugly maven behavior you might encounter is that if you declare a dependency before you actually install it, maven will create an empty version of the missing dependency (folder with metadata but no jar), and you will have to manually clean your .m2 repository.
Third, an installed archive (jar...) can get corrupted, so try to open it with any archive tool (7zip...) to test it, and delete the whole folder if the archive is corrupted.

In my case I had to manually delete all the files in .m2\repository folder and then open command prompt and run mvn -install command in my project directory.

I was using Eclipse as IDE and I was getting very same error. I had to do Project->Maven->Update Project. Select all the checkboxes below except "offline" esp. the one "Force update of snapshots/releases" and click OK. Did the Clean Build for the Project again.

Delete corrupted files from your local .m2 repository and Ctrl+F5 (Update Maven Project) in Eclipse/STS. It'll download and install these files.

This worked for me.
Close Eclipse
Delete ./m2/repository
Open Eclipse, it will automatically download all the jars
If still problem remains, then right click project > Maven > Update Project... > Check 'Force Update of Snapshots/Releases'

Below Steps resolved my issue.
Go to ./m2/repository folder.
Go to respective archive error folder.
Verify any zip file is exist.
delete error name folder.
Now come to Eclipse Project - Right Click - Maven - > Update Project.
Above trick works for me.

For Googlers:
In my case I had accidentally manually added a Java class to the build path while poking around Eclipse. By taking a look at the 'Configure Build Path...> Libraries I removed the culprit class and now only have the
JRE System Library
Maven Dependencies
and nothing is complaining.

In my case I tried all the tips suggested but the error remained. I solved changing with a more recent version and writing that in the pom.xml. After this everything is now ok.

I deleted the local maven repository.
Then just rightclick the project -> Maven -> Update Project...
Select all concerned projects and click OK.

I was facing the same problem with my project.
My project was not able to find this archive: -
C:\Users\rakeshnarang\.m2\repository\org\hibernate\hibernate-core\5.3.7.Final
I went to this directory and deleted this folder.
Went back to eclipse and hit ALT + F5 to update the project.
The jar file was downloaded again and the problem was solved.
You should try this.

This happens when Eclipse screws up. To fix it, delete all the files in:
workspace/.metadata/.plugins/org.eclipse.jdt.core

Remove maven dependenices from build path

I faced this problem. I had "Archive for required library spring-boot-devtools cannot be read or is not a valid ZIP file" and the solution was like that:-
1- determine the dependencies names that have problems(for may case it is spring-boot-devtools).
2- close eclipse.
3- search in your .m2 file on these dependencies(by name).
4- delete these folders.
5- reopen eclipse and let maven rebuild your dependencies again.

Ok, I had the same problem with STS on a mac and solved it by deleting all the files in repository folder and from the STS IDE click on the project and then Maven -> Update project. Give it a couple of minutes to download all the dependencies and the problem is solved.

I face with the same issue. I deleted the local repository and relaunched the ID. It worked fine .

Just had this problem on Indigo SR2. It popped up after I removed a superfluous jar from the classpath (build path). Restarting Eclipse didn't help. Added back the jar to the build path...error went away. Removed the jar once again, and this time I was spared from another complaint.

none of the solutions above helped my problem. I've resolved it by deleting all files in {projectworkspace}/.metadata folder AND in {location}/.m2 folder and let eclipse download every single thing again. Hope this helps someone, cheers!

When I got an error saying "archive for required library could not be read," I solved it by removing the JARS in question from the Build Path of the project, and then using "Add External Jars" to add them back in again (navigating to the same folder that they were in). Using the "Add Jars" button wouldn't work, and the error would still be there. But using "Add External Jars" worked.

This could be due to you have added spring-licence.txt file to your web app libraries.
I had similar issue and resolved after removing that text file. In libraries it will expect jar file only.

Alternatively, below commands also worked for me:
mvn -s settings.xml eclipse:clean
mvn -s settings.xml eclipse:eclipse

In case of VSCode, follow the below steps:
Navigate to the respective folder that contains the corrupted jar
Delete just the jar
mvn clean
mvn compile
That worked for me.

Read the issue in Problems section,identify which dependency not able to read, then go the maven repository .m2\repository ->
1)check the dependencies and delete it from the folder
2)go to STS/Eclipse -> click on maven -> update project ->select the force update of snapshots/releases and click on ok.
or
delete the dependencies from the .m2/repository and rebuild the maven --> update the maven project

In my case, I just had to remove the following 2 lines from proguard.cfg:
-keep class android.support.v4.** { * ; }
-dontwarn android.support.v4.**
Yes, I know that the question refers to the Spring Tool Suite but:
Spring Tool Suite is based on Eclipse (the IDE I am currently using for ADT).
Proguard is a Java obfuscator that can be used for any project, not just Android
I tried all the suggested answers and tips in the thread and none worked for me, until I removed the references to said libs.
I hope this helps someone.

Delete your C:\Users\PC\.m2** folder
and update maven project