When I run the program, the following window opens
What's the matter? I had this package in all previous projects and there were not any problems
You need to define a module which classpath should be used for that run configuration - Use classpath of module setting
Related
What are the possible causes of a "java.lang.Error: Unresolved compilation problem"?
Additional information:
I have seen this after copying a set of updated JAR files from a build on top of the existing JARs and restarting the application. The JARs are built using a Maven build process.
I would expect to see LinkageErrors or ClassNotFound errors if interfaces changed. The above error hints at some lower level problem.
A clean rebuild and redeployment fixed the problem. Could this error indicate a corrupted JAR?
(rewritten 2015-07-28)
Summary: Eclipse had compiled some or all of the classes, and its compiler is more tolerant of errors.
Long explanation:
The default behavior of Eclipse when compiling code with errors in it, is to generate byte code throwing the exception you see, allowing the program to be run. This is possible as Eclipse uses its own built-in compiler, instead of javac from the JDK which Apache Maven uses, and which fails the compilation completely for errors. If you use Eclipse on a Maven project which you are also working with using the command line mvn command, this may happen.
The cure is to fix the errors and recompile, before running again.
The setting is marked with a red box in this screendump:
try to clean the eclipse project
you just try to clean maven by command
mvn clean
and after that following command
mvn eclipse:clean eclipse:eclipse
and rebuild your project....
Your compiled classes may need to be recompiled from the source with the new jars.
Try running "mvn clean" and then rebuild
The major part is correctly answered by Thorbjørn Ravn Andersen.
This answer tries to shed light on the remaining question: how could the class file with errors end up in the jar?
Each build (Maven & javac or Eclipse) signals in its specific way when it hits a compile error, and will refuse to create a Jar file from it (or at least prominently alert you). The most likely cause for silently getting class files with errors into a jar is by concurrent operation of Maven and Eclipse.
If you have Eclipse open while running a mvn build, you should disable Project > Build Automatically until mvn completes.
EDIT:
Let's try to split the riddle into three parts:
(1) What is the meaning of "java.lang.Error: Unresolved compilation
problem"
This has been explained by Thorbjørn Ravn Andersen. There is no doubt that Eclipse found an error at compile time.
(2) How can an eclipse-compiled class file end up in jar file created
by maven (assuming maven is not configured to used ecj for
compilation)?
This could happen either by invoking Maven with no or incomplete cleaning. Or, an automatic Eclipse build could react to changes in the filesystem (done by Maven) and re-compile a class, before Maven proceeds to collect class files into the jar (this is what I meant by "concurrent operation" in my original answer).
(3) How come there is a compile error, but mvn clean succeeds?
Again several possibilities: (a) compilers don't agree whether or not the source code is legal, or (b) Eclipse compiles with broken settings like incomplete classpath, wrong Java compliance etc. Either way a sequence of refresh and clean build in Eclipse should surface the problem.
I had this error when I used a launch configuration that had an invalid classpath. In my case, I had a project that initially used Maven and thus a launch configuration had a Maven classpath element in it. I had later changed the project to use Gradle and removed the Maven classpath from the project's classpath, but the launch configuration still used it. I got this error trying to run it. Cleaning and rebuilding the project did not resolve this error. Instead, edit the launch configuration, remove the project classpath element, then add the project back to the User Entries in the classpath.
I got this error multiple times and struggled to work out. Finally, I removed the run configuration and re-added the default entries. It worked beautifully.
Just try to include package name in eclipse in case if you forgot it
Import all packages before using it, EX: import java.util.Scanner before using Scanner class.
These improvements might work and it will not give Java: Unresolved compilation problem anymore.
Also make sure to check compiler compliance level and selected jdk version is same
As a weird case, I encountered such an exception where the exception message (unresolved compilation bla bla) was hardcoded inside of generated class' itself. Decompiling the class revealed this.
I had the same issue using the visual studio Code. The root cause was backup java file was left in the same directory.
Removed the backup java file
When the build failed, selected the Fix it, it cleaned up the cache and restarted the workSpace.
I have a JDK 9 project. When running mvn install, everything works fine. When using IntelliJ 2017.2.6 with JDK 9.0.4 I come up
with dozens of compilation errors due to split packages. For example, in my POM I set a dependency on org.apache.solr:solr-core:7.2.1. One of the errors displayed by IntelliJ is:
Error:java: module solr.core reads package org.apache.lucene.search from both lucene.misc and lucene.sandbox
The rationale for the compilation error issued by IntelliJ is:
solr-core has Maven dependencies on artifacts lucene-misc and lucene-sandbox
Both lucene-misc.jar and lucene-sandbox.jar define classes in package org.apache.lucene.search
IntelliJ considers that lucene-misc.jar and lucene-sandbox.jar are JDK 9 modules (if fact, they are not modules, they have no module-info.java file). As two JDK 9 modules cannot participate to the same package, IntelliJ issues a compilation error.
By contrast, the Maven compiler pluging issues no error, because it considers lucene-misc.jar and lucene-sandbox.jar as belonging to
the class path, not to the module path.
I obviously don't want to re-package the Lucene stuff.
So my problem boils down to the following: how can I mute IntelliJ errors Error:java: module Mod1 reads package P from both Mod2 and Mod3?
[Short]
It's impossible if you want to run your application from a module code. You have to migrate your code which depend on collision JARs to non-module code and add your collitions jar on the class path. (as suggested in comments)
[Long]
Behind the scene the Intellij try to run the JVM, so the Intellij can run your application only if the JVM can do that.
When you run an application from module jar, that means that you run your application from named module. The module must require all of its dependencies which should be name modules. Note that even automatic modules which are created from your non-module JARs are indeed named.
Java 9 does not allow split-packages for the reason of the reliable configuration, only unnamed modules are excepted from this rule.
The only way to make it works it move your collision jars to unnamed module, but named module cannot depend on unnamed module
A named module cannot, in fact, even declare a dependence upon the unnamed module. This restriction is intentional, since allowing named modules to depend upon the arbitrary content of the class path would make reliable configuration impossible.
so if you don't want repackage collision jars you have to move your modules which require collision jars to non-module jar.
Your maven plugin done with it, because as #Nicolai said:
Maven places them on the class path (where split packages don't matter), whereas IntelliJ places them on the module path (leading to the problems you observe).
See also this answer about running the application from non-module code.
I'm running unit tests in Intellij 14.1.2 with the Gradle plugin. I have external config and test data that is in environment specific in a set of directories (directory for each env). I want to load the config and data via the classpath.
In Eclipse I'd just add the env specific path to the run-config and save the config as:
'Test-XYZ-UAT1'
for example.
In intellij, it seems my application config classpath is tied to my 'module' classpath:
https://www.jetbrains.com/help/idea/2016.3/run-debug-configuration-application.html
how to add directory to classpath in an application run profile in intellij idea?
..which is bad enough but for the Gradle run configs I don't even have the option to add the module classpath.
Run/Debug Configurations window has no:
'Use classpath of mod...'
section.
Question:
How can I set the classpath of the run config when running a Gradle Task within Intellij ?
..and if someone could tell me how to get application run config specific classpaths setup that would be even better.
(please tell me I'm missing something ingenius about Intellij..)
Based on quite a bit of research and trial and error, here is the solution that works for my Kotlin based Spring Boot project.
Background:
My Spring Boot project run configuration is configured to use Run Gradle task in place of the standard IDEA build as its Before launch configuration (see screen shot below).
My Spring Boot project uses src/main/resources/application.properties for JPA and logging properties.
gradle build uses the following output directories for the build. These are the default gradle build output directories for a Kotlin project.
build/classes/kotlin/main for the main class files.
build/classes/kotlin/test for the test class files.
build/resources/main for the main resource files. This is where application.properties is copied during a build.
When I attempted to run this project inside IDEA using the run configuration above, it would fail during Spring Boot start up because it could not find application.properties inside the classpath. When I inspected the classpath used during application startup, build/resources/main was missing.
My Solution
Use the information from: Gradle Goodness: Delegate Build And Run Actions To Gradle In IntelliJ IDEA to delegate IDEA build and execution to Gradle.
When IDEA is configured to delegate build and execution to Gradle, the main and test modules should be configured as follows: On the Paths tab, select Inherit project compile output path.
I'm trying to create an executable jar from IntelliJ.
First I got the Java Security Exception and I changed sqljdbc4-4.0 to unsigned. First problem solved.
Then I got Manifest not found. Added META-INF dir to output. Second problem solved.
Next I got the BeanCreationException (unsolved):
Caused by: org.springframework.beans.factory.BeanCreationException: Cannot determine embedded database driver class for database type NONE. If you want an embedded database please put a supported one on the classpath.
In IntelliJ it is working.
I think the resources are not in the output. (application.properties, ...)
In which way do I add the resources or where are they stored in the jar.
I'm using gradle and on the spring boot homepage are only instructions for maven.
You should use spring-boot-maven-plugin or spring-boot-gradle-plugin, depending on your preferred build system.
EDIT:
Just run ./gradlew build
I suggest to dive into this getting started guide. It clarifies a lot of stuff for beginners.
A typical Spring boot project is a Maven project or a Gradle-Project (I only know how to do it with Maven, for Gradle see [luboskrnacs answer][1]). So you just need to run the maven targetpackageand pick the jar form the (created)target` folder
use a shell, go to the project root directory (where the pom.xml file is) and type
mvn clean package
cd target
the there is the xxx.jar file.
I have a RCP project where I cannot fix a NoClassDefFoundError: One plugin depends on another plugin. The plugin-dependencies are set in the manifest, packages exported, and there is no error at compile time. Both plugins are in the product dependencies and visible in the installation details of the product.
But when I run the application I get a java.lang.NoClassDefFoundError when the one plugin wants to use a class from the other plugin.
Any hints how to find the reason for this are greatly appreciated.
Thanks,
Michael
I found the problem: I created the plugin which could not be loaded from an existing Java project. And somehow I deleted the "." in the entry Bundle-classpath in the plugin manifest (the plugin has some jars which -> so lib/xyz.jar was in the Bundle-classpath entry but not the ".").
For the class-loader of the bundle the "." means to search for classes from the root path of the bundle (or something like that), so it could not find the classes. However, there were no errors in the IDE so it was hard to find.
Is the configuration for running the application correct i.e. all dependencies are also put in the running configuration?