Error Could not find or load main class springboot eclipse - java

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

Related

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!

Maven missing classes

I created a basic maven project in eclipse and I'm getting errors in my pom.xml that classes are missing, I checked the folder that it was looking in and the file paths don't match what I have and the classes don't exist.. My path goes up to: C:\Users\user.m2\repository\org\apache\maven\shared and it is stating there is a /filtering/ folder which I don't have. I have the latest maven and m2eclipse installed.
Most probably a bad installations (incomplete download or missing jars). I suggest you delete the
C:\Users\user.m2\
folder completely and run mvn clean install again. Maven will fetch the jars for you. Also try to refresh the maven project from within eclipse. Right click on project -> maven -> update project. Sometimes eclipse has this issue.

Compilation unit is not on the build path of a Java project

I joined an SVN server and checked out the source files a project from that server. In the Eclipse editors, when I hit Ctrl + Space, I got the following error message:
This compilation unit is not on the build path of a Java project
What should I do to solve this problem?
Read this guide on how to use maven projects with eclipse
http://maven.apache.org/guides/mini/guide-ide-eclipse.html
Taken from the above link :
Reason why you get that notice :
Eclipse needs to know the path to the local maven repository. Therefore the classpath variable M2_REPO has to be set.
Solution
Execute the following command:
mvn -Declipse.workspace=<path-to-eclipse-workspace> eclipse:add-maven-repo
Restart your Eclipse IDE (if you already have it open) for this change to take effect.
You can also define a new classpath variable inside eclipse: From the menu bar, select Window > Preferences. Select the Java > Build Path > Classpath Variables page
For Simple Projects :
If you have a simple java project which is made up of only one module, using eclipse is very simple. To generate the eclipse project files from your POM you execute the following command:
mvn eclipse:eclipse
If you have created or checked out the project with eclipse, you only have to refresh the project in your workspace. Otherwise you have to import the project into your eclipse workspace (From the menu bar, select File >Import >Existing Projects into Workspace). In the latter case the project (directory) should not be located in your workspace, because eclipse might come into trouble, especially if you want to use eclipse as the scm client.
For a more detailed explanation refer the above link.
Import project as maven project.
File-> import-> Maven-> Exiting Maven Project-> Next-> Root Directory-> Browse your project from Disk
Follow these steps:
Right click project in Eclipse. Select to Run As → Maven build...
In Goals add eclipse:eclipse
Select Run
Wait for build to finish
Right click project in Eclipse. Select Refresh
This is due to the issue in build path .
If you had imported the project as Existing Maven project, do the following to resolve the issue.
Right click in the Package Explorer -> Maven -> Update project.
Or select the project in package explorer and perform Alt+F5 which is the shortcut for the maven project update.
Execute mvn eclipse:eclipse on command line and once the build is successful, refresh your project in eclipse. This resolve the issue.

Converting SVN project to maven project in Eclipse

I have downloaded a project (Maven based structure) from our SVN repository using Eclipse SVN plugin. Initially, Eclipse wasn't recognizing it as java project so I had to follow the following steps:
http://www.javaexperience.com/how-to-convert-svn-project-to-regular-eclipse-java-project/
The above steps worked well and the project was converted to java project.
Next I right clicked on the project and selected maven->Convert to maven project. Eclipse downloaded some jars and added it to the class path but not all files seem to have been downloaded successfully as I see Junit jar file missing error (where as junit is mentioned in pom.xml)
When I right click on the pom.xml file, I don't see the option "mvn install" or "mvn clean". I am using Eclipse Kepler which comes with maven plugin out of the box.
You will find the Maven commands in 'Run As', not in 'Maven'
I would first create a maven project using create maven project menu then add the SVN based source code to it.

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

Categories

Resources