I have a program which runs as a Spring boot App in eclipse. The program was running fine. Then i did the following:
Right click on project -> Run As -> Maven Test .
This was accidental. When i then tried to run the program as a spring boot app again, it threw the following error below.
Error: Could not find or load main class com.bt.collab.alu.api.webapp.Application
How do i point the application back to my main class?
Thanks
I had the same problem. Try this :
Right Click the project -> Maven -> Update Project
Then Re-run the project. Hope it work for you too.
Main class is configurable in pom.xml
<properties>
<start-class>com.bt.collab.alu.api.webapp.Application</start-class>
</properties>
Have a look under "Run -> Run Configurations..." in Eclipse. You should delete the new one which you created by mistake, you should still have the existing one.
I suspect it has created a new run configuration for the "Run as Maven Test" and you are now always starting this one.
If you're using Spring Boot and the above suggestions don't work, you might want to look at the Eclipse Problems view (available at Window -> Show View -> Problems).
For example, you can get the same error (Error: Could not find or load main class groupId.Application) if one of your jar files is corrupted. Eclipse will complain that it can't find the Applications class, even though the bad jar is the root cause.
The Problems view, however, will identify the bad jar for you.
At any rate, I had to manually go to my local mvn repo (in .m2) and manually delete the corrupted jar, and update it (right click on the project in the Package Explorer), Maven --> Update Project... -> OK (assuming that the correct project is check-marked).
I tried all the above solution, but didn't worked for me.
Finally was able to resolve it with a simple fix.
on STS,
Run Configuration > open your Spring Boot App > Open your configuration,
Follow the steps,
In Spring boot Tab, check your Main class and profile.
Then go to classpath tab, In the bottom you will see two checkboxes,one is "Exclude Test Code"(Check this if you do not want to run test classes) and other, "Use Temporary Jar file to specify classpath" (this is necessary).
Save your configuration and run.
This happened to me after i updated the pom (Added some dependencies).
The following step helped me to avoid this error
right click on the project > maven > update project
Intellij
close Intellij
remove all files related to Intellij (.idea folder and *.iml files)
open the project in Intellij as if it was the first time (using open recent won't work, id needs to be done via file -> open)
Use spring-boot:run command to start spring boot application:
Precondition:
1. Add following property to pom.xml
<property>
<start-class>com.package.name.YourApplicationMainClass</start-class>
</property>
2. Build your project
Then configure maven command with spring-boot:run.
Navigation:
Right Click Project | Run As | Run Configuration... | Add new Maven Configuration with command spring-boot:run
In case if someone is using Gradle for the build then fix will be by adding the following lines in build.gradle file
apply plugin: 'application'
mainClassName = "com.example.demo.DemoApplication"
The solution for me was:
Boot Dashboard, right click on your Instance.
Open Config
Tab Spring Boot
Main Type, there was the path to the application file missing...
I know this is pretty late answer. But it might still help some new learners.
The Following example is only for springboot with NETBEANS.
I had to do the following steps:
Step 1. Follow #Mariuszs answer .
Step 2. Right click on project -> Properties -> RUN.
Make sure the Main Class field is has the correct starter class else Click browse and select from the available classes .
Step 3. Click OK-> OK. Thant is all. Thank you.
I have used spring 1.5.3.RELEASE version and given pom dependencies like
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.3.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
</dependencies>
And my main class was
#SpringBootApplication
public class SpringAppStarter {
public static void main(String[] args) {
SpringApplication.run(SpringAppStarter.class, args);
}
}
But still while execution of main class I was getting:
Could not find or load main class ... with my class name.
I could see that class was available in the class path and I was using STS IDE.
I was not getting reason for the issue then I tried manual build through maven with
mvn clean install
Still problem was there then i realize that my project has two libraries
Reference Library
Maven Library
What I did:
I have created another mavenRepo folder and build it again and refresh my project. After that it worked and I saw that Maven Library was deleted from project class path.
Issues was while execution it was getting multiple version so it was not able to find proper class to execute my application.
Other Solution listed in this page also resolves the issue but if you are doing mistake in
Annotating class
pom entry
jar version etc.
Hope this may resolve problem if somebody get this issue
deleting old jars from .m2 and updating maven project should be primary step.
In most of the cases it resolves the issue.The reason for this issue is mostly corrupted old jars
Encountered the same issue and was able to fix it by the following the steps listed below:
File -> Invalidate Cache and Restart
File -> New -> Project from existing source
Select the pom.xml file just (not the whole project directory) to load the project. Project will be setup automatically.
Error:Could not load or find main class
Project:Spring Boot
Tool:STS
Resolve Steps:
Run the project
See in problems tab, it will show the corrupted error
Delete that particular jar(corrupted jar) in .m2 folder
Update project
Run successfully
I was having the same problem just delete .m2 folder folder from your local repositry
Hope it will work.
start-class doesn't work for me, I fixed it by adding build plugins to pom.xml, and executions is necessary.
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
There are good answers here, but maybe this one will also help somebody.
For me it happened just after i deleted .idea (with IntelliJ), and reimported the project.
then this issue started, i tried to run mvn compile (just via IDE Maven toolbar), once i fixed few compilation errors, issue disappeared
If you came across the
error:could not find or load main class in maven project
do this it worked for me:
Reason for the error: The reason for this error is the jar file or dependency to run a maven project is not installed correctly.
Solution for the error: Go to the project folder (eg: D:\office\OIA-service-app)
in the address bar of computer type command cmd and press enter.
In the command prompt type command mvn clean install make sure you have the internet connection.
If your project packaging type war you could not start. I was using maven assembly plugin with this configuration;
<build>
<plugins>
<plugin>
<artifactId>maven-assembly-plugin</artifactId>
<version>3.0.0</version><!--$NO-MVN-MAN-VER$ -->
<configuration>
<descriptors>
<descriptor>assembly.xml</descriptor>
</descriptors>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
<archive>
<manifest>
<mainClass>com.ttech.VideoUploaderApplication</mainClass>
</manifest>
</archive>
</configuration>
<executions>
<execution>
<id>make-assembly</id> <!-- this is used for inheritance merges -->
<phase>package</phase> <!-- bind to the packaging phase -->
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
and my packaging tpe was war i got cannot find main class exception bu i changed packaging to jar it worked;
<groupId>com.ttect</groupId>
<artifactId>VideoUploadListener</artifactId>
<version>1.0.0</version>
<packaging>**jar**</packaging>
In my case the following helped:
Added the following section in pom
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<executable>true</executable>
</configuration>
</plugin>
</plugins>
Ran it using maven3 and it worked
I also got this error, was not having any clue. I could see the class and jars in Target folder. I later installed Maven 3.5, switched my local repo from C drive to other drive through conf/settings.xml of Maven. It worked perfectly fine after that. I think having local repo in C drive was main issue. Even though repo was having full access.
I was facing the same problem. I have deleted the target folder and run maven install, it worked.
I had similar kind of problem while I was adding spring security dependency to my project ,
then I deleted my target folder and used maven update again .
It's worked for me.
Even I faced the same issue, later I found that it happened because the maven build operation was not happening properly in my environment. Please check it in your case also.
I ran into same error, although i was using gradle build. Delegating IDE build/run actions to Gradle is solved my problem.
Intellij:
Settings -> Build, Execution, Deployment -> Build Tools -> Gradle -> Runner
I got the same error in the "Spring Tool Suite" software.
In my case, I have Java 8 installed and I created a project of Java 11. And when I run the project I got the same error, like " can not find main class ".
Then I created a project in Java 8 and the problem resolved.
(Eclipse) Updating maven project was not working for me. What I had to do was to go in Run configurations, and in "Main" tab, in "Project" field, write the whole package name com.bla.blabla.MyMainClass (instead of just the Main class name).
The error happened because I have several projects with the same name, but in different packages.
if none of above solutions work, try to replace build tag with this inside pom file :
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins></pluginManagement>
</build>
I am new in spring boot and using STS with maven build. I did all the things mentioned above but won't work for me. I noticed two problems in problem window of STS. There was a missing jar file on the path (C:\Users\UserName.m2\repository\com\jayway\jsonpath\json-path\2.2.0). I did following, the way is not strongly suggested but worked for me.
1) I deleted .m2 folder from the path location
2) Restarted STS
3) Right Click on project folder -> maven -> update project -> checked "Force update of snapshots/releases" -> Click Ok.
Maven updated its dependencies and the problem is solved.
Related
I am trying to write a sample REST web services demo using Jersey.
After creating a Maven project - this is the error I have
Description Resource Path Location Type Cannot read lifecycle mapping
metadata for artifact
org.apache.maven.plugins:maven-clean-plugin:maven-plugin:2.5:runtime
Cause: error in opening zip file pom.xml /MyRestDemo line 1 Maven
Project Build Lifecycle Mapping Problem
Screen shot
Per suggestions on previous stack overflow posts,
I have deleted the .m2 repository and updated the project - error persists.
I have deleted just maven - clean plugin still have the same error.
I have the same error with both Eclipse Neon and Luna and I am stuck at this point.
Thanks
Set of Actions that could be taken according to eclipse foundation: https://www.eclipse.org/m2e/documentation/m2e-execution-not-covered.html
Modify you POM.xml with below plugin.
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.1</version>
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
</plugin>
</plugins>
The above should work fine, if still you are facing problem then Go to
.m2/repository , delete all files. come to eclipse and rebuild your project.
One more reason for the above error could be a bad download of artifact, please check the proxy details of your company or home in (~/.m2/settings.xml)
This is an extremely weird error message:
org.apache.maven.plugins:maven-clean-plugin:maven-plugin:2.5:runtime
Cause: error in opening zip file pom.xml
"ZIP file pom.xml"? Why would it think that? Maybe try to run Maven from the command line (or using Run -> "Maven ..." inside of Eclipse). That might give you a different / better error message.
If that doesn't help, some background: m2e (the Maven plugin for Eclipse) tries to figure out which Maven targets it should run as part of the build inside of Eclipse. mvn clean is one of them. To see what m2e thinks, select the project, right click, Properties, Maven, "Lifecycle Mapping".
The target clean:clean should be mapped to "ignore" since Eclipse already does that well.
Which makes me wonder why it wants to run in your case.
If the mapping is correct for you, then sometimes m2e get stuck in weird ways. Try to update the project (right click project, Maven, "Update Project..."). Make sure "Update project configuration from pom.xml" is enabled.
If that also doesn't work, then something broke your Eclipse installation. Try to install the latest version of Eclipse and try to open the project there.
Reload of multi-module maven project changes
Setting
Imagine a multi-module maven-project. The project structure is:
pom.xml //parentpom
|
pom.xml //submodule_1
|
pom.xml //submodule_2
.
.
.
pom.xml //submodule_7
For example submodule_5 has submodule_6 and submodule_7 as dependencies. The submodule_5 can be build to construct a War-file which can be deployed. Spring-Boot-Devtools provide the feature of automatic-restart whenever there is a change to submodule_5 it's classpath.
Whenever the application is run using:
mvn spring-boot:run
And changes are made to submodule_5 (depending on which IDE you use the classpath get changed. (for Eclipse automaticaly / for InteliJ when pressing Ctrl+F9)) spring-boot automaticaly restarts the application and changes are added. Changes which happen to submodule_6 or submodule_7 don't trigger the automatic restart.
Questions
Is there a way to make it so that whenever you make changes in submodule_6 or submodule_7 to have them force a restart and there-for apply the changes?
Spring-boot-devtools uses two classloaders: "The Base Classloader" & "The Restart Classloader". Is it so that on initial start of the application submodule_6 and submodule_7 get added to "The Base Classloader" whilst submodle_5 is kept in the "The Restart Classloader"? Making it so that whenever submodule_5 forces a restart it uses the versions of submodule_6 and submodule_7 out of "The Base Classloader"?
You may specify additional folders to be watched by spring-boot-devtools, in application.properties:
spring.devtools.restart.additional-paths=../submodule_6,../submodule_7
See Spring's documentation on using-boot-devtools-restart-additional-paths.
To fix this problem I started running the application from within InteliJ. without having to add.
spring.devtools.restart.additional-paths=../submodule_6,../submodule_7
IntelliJ and spring-boot seem to work together very wel. The reason it was not working for me in the first place was because I was working from the commandline at first.
Difference between commandline and IDE
So spring-boot-devtools uses two classloaders to load an application. Jars will be loaded ones in the "Base classloader", your application will be loaded in the "restart classloader". This last classloader will restart everytime there is a change on the classpath.
Whenever running submodule_5 from the commandline, it will build the submodule_6 and submodule_7 and add the jars to the build of submodule_5. Whenever changes are made in submodule_6 and submodule_7 spring-boot won't even notice since it's only watching submodule_5 and has the jars it needs. Even if you would specifically tell it to also watch those submodules, it still won't rebuild those, it'll just keep using the jars it already has loaded in the "base classloader" (This is my assumption, I'm not 100% certain of the way it works).
Whenever running submodule_5 from the IDE, it won't create the jar of the submodule_6 and submodule_7. It will just use their classpath. This makes it so that changes in your intire project's classpath (all submodules) will trigger the automatic restart and the changes will be applied.
EXTRA
Whenever running from the IDE changes to resources like html-files, css-files, xml-files . . . won't trigger a restart since this is not a change in the classpath. But the changes will still be visible.
I tried with spring.devtools.restart.additional-paths and in any case it is useless : source change restart the application but helpless because the application doesn't have the target/classes of modules during its execution.
With spring-boot:run executed on quite recent IntelliJ versions : it works out of the box.
With spring-boot:run executed on command line : there are at least two cases.
Case 1) we want to execute spring-boot:run from the module that has the spring boot main class (submodule_5 in the op question).
We need to add in the plugin configuration of its pom.xml the additional classpaths of compiled classes that we want that spring-boot plugin be aware it :
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<folders>
<folder>
../submodule_6/target/classes
</folder>
<folder>
../submodule_7/target/classes
</folder>
</folders>
</configuration>
</plugin>
</plugins>
</build>
Case 2) we want to execute spring-boot:run from the parent-module.
It works only with pom multi-modules that are also parent of modules.
We need to do two changes :
First, add the spring boot plugin declaration with flag skip in the parent pom :
`<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>2.4.1</version>
<configuration>
<skip>true</skip>
</configuration>
</plugin>
</plugins>
</build>`
Then add in the pom.xml of the module that has the spring boot main class (submodule_5 in the op question) :
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<skip>false</skip>
</configuration>
</plugin>
</plugins>
</build>
We can now start the application from the parent pom with :
mvn -pl submodule_5 -am spring-boot:run
FYI these maven flags specify to apply the goal on submodule_5 after applied that on its dependencies (whereas the skip flag in the multi/parent pom.xml).
I'm trying to work around a maven bug MDEP-187 ( https://issues.apache.org/jira/browse/MDEP-187 ) by not using workspace resolution.
This forces me to do a mvn install for all my dependencies, I'm doing this by creating a launch configuration in eclipse with goal install.
The problem is that i have to create a launch config for every project in my multiproject workspace, in addition to install i have to manually call every launch config and run it. Which just doesn't work.
Is it possible to automatically install a project in the local repository? (whenever i update my code)
If you don't need to run dependency:copy in Eclipse, you can use following work-around:
Add a profile to your pom.xml, something like this:
<profiles>
<profile>
<id>copy</id>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<version>2.10</version>
<executions>
[...]
</executions>
</plugin>
</plugins>
<build>
<profile>
</profiles>
Enable workspace resolution in Eclipse.
Then Eclipse will not use dependency:copy, but you can use dependency:copy with command line: mvn install -P copy.
I did go with #khmarbaise solution:
But than you need to can handle the whole thing via
maven-assembly-plugin which can create archives / folders with all the
dependencies. Apart from that a swing ui must be started somehow which
will need some kind of shell script / batch file which you can create
by using appassembler-maven-plugin...And it sounds like you need to go
for a multi module project in maven..cause you might have parts like
core, ui, etc. which are needed to be combined in the end.
#khmarbaise i was in the understanding that the assembly-plugin didn't
support putting dependencies in a lib/ folder (just putting everything
in 1 big jar), but after a little bit of trying i just go myself a zip
with a runnable jar and my dependencies in a lib/ folder. Tomorrow i'm
going to read a bit more about the assembly-plugin. I'm happy ;-
I'm doing some testing work that requires the use of features in JUnit which are unfamiliar to me. In order to better understand these features I'd like to be able to view the JUnit sources inside IntelliJ alongside my project.
This project uses Maven. I have the following dependency for jUnit listed in my pom.xml file:
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.10</version>
</dependency>
When I run "mvn clean install" on the command line the jUnit sources are downloaded from my company's Maven repository into my local Maven repository (.m2 directory). The project then compiles and runs without issue.
After right-clicking on the pom.xml file and selecting Maven->Reimport I can see that the classes, sources, and javadocs for jUnit are also present in the library settings in IntelliJ:
However, when I try to open a jUnit class file in IntelliJ and click on the "Download Sources" link I see this:
It seems to might like IntelliJ should be finding these sources just fine locally. Even if it did have to download them from my company's repository I also believe it should find them there since that's where the junit-4.10-sources.jar file in my local repository originally came from.
What might be keeping IntelliJ from loading the sources from the JAR file that it already knows about?
I was able to replicate this in IntelliJ 16 on Windows.
Here is how I resolved it:
Choose file -> Settings -> Build, Execution, Deployment -> Build Tools -> Maven -> Repositories
Select Your local repository from the list (or add it if it is not there)
Click the 'Update' button
Click ok
Right click your pom.xml file and select Maven -> Reimport
I had the same problem. In my case I have 2 projects developed locally (project A and B) where project B is a dependency of the project A. I solved it by:
First: On project B add the following plugin to your pom file:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-source-plugin</artifactId>
<version>3.2.0</version>
<executions>
<execution>
<id>attach-sources</id>
<phase>verify</phase>
<goals>
<goal>jar-no-fork</goal>
</goals>
</execution>
</executions>
</plugin>
More info about this plugin here: https://maven.apache.org/plugins/maven-source-plugin/usage.html
Second: On project B root folder run: mvn source:jar followed by mvn install.
The first command will generate the sources and the second will publish them in your local repo.
Then IntelliJ, on project A, automatically picked up the sources from project B. If it doesn't then you may need to reload your project dependencies on project A or run mvn clean install on the root folder
I'm using Intellij 13 Ultimate on Windows 7 enterprise. My maven pom includes the following:
<reporting>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-javadoc-plugin</artifactId>
<version>2.9.1</version>
<configuration/>
</plugin>
</plugins>
</reporting>
I have settings.xml configured to access Nexus repositories within the firm for whom I am working.
Within intellij, the '2.9.1' displays in red and I see : Plugin "org.apache.maven.plugins:maven-javadoc-plugin:2.9.1" not found.
At the windows command line, though, I am able to download the artifact to the local repo using the same settings.xml file and the command:
C:\swdtools\apache-maven-3.1.1\bin>mvn org.apache.maven.plugins:maven-dependency
-plugin:2.1:get -DrepoUrl=https://dsnexus.uk.<HIDDEN>.<HIDDEN>:8081/nexus -Dartifact=org
.apache.maven.plugins:maven-javadoc-plugin:2.9.1
Intellij doesn't pick it up if I do 'reimport all maven projects'.How to fix or debug this further within intellij?
I have the same issue while including the report plugin "maven-jxr-plugin" with IDEA 13, but other plugins are work well.
The plugin could be found in Central Repo, but not in local.
One solution is to move the declaration from report section to build section, then the downloading will be triggered, and the reporting still works.
I changed config intellij's config dirs in 'idea.properties' and found the 'idea' log file. The dependency problem went away as soon as I changed config dirs, no explanation, except that i didn't realize intellij was throwing errors until I ran 'idea.bat' at the command line. So - 1/ run from command line 2/ look into idea log file for unexplained problems