Eclipse for Java shows Multiple Errors - java

This is my current configuration:
Eclipse IDE for Java Developers
Luna Service Release 2 (4.4.2)
Java Version 8 Update 45 Build 1.8.0_45-b15
After a time without using some Java Project folders, now Eclipse throws a lot of syntaxis errors over them:
The import javafx cannot be resolved
*** cannot be resolved to a type
The method join(String, List<String>) is undefined for the type String
The project folder never change from their location, they were error and warning free prior to left them abandoned.
I am not sure about a missing .metadata or .reccomenders or a Java version change -over no more than two months- for these projects.
What should i do to solve that?

Try cleaning your project by going to the following menu item:
Project > Clean...
If that doesn't work:
Try removing the jars from the build path and adding them again.
Double-check the jars being really on the build path (with no errors).
Make sure there is nothing in the "Problems" view.

Related

Can not import module-based maven java 11 project to Eclipse correctly (with module-info files)

When I import java 11 maven project with modules to latest versions of Eclipse I got a whole bunch of hardly visible error, that seems to be whole inconsistency. Indeed when opening in Intellij IDEA or NetBeans it does imports correctly. The first ample error is "The project was not built since its build path is incomplete" - "Cannot find the class file for java.lang.Object. Fix the build path then try building this project." This error appears in two child modules. (This project is docker-based, multimoduled although import of another simple module-infos project also cannot be imported correctly in Eclipse). Next 2 errors are produced in two classes of aforementioned maven modules: " The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class files. "
Manipulation with adding JDK 11 to submodules buildpath just leads to the thousands of problems. Such big bunch of errors also appears when I use Eclipse-File-Maven-Update. Moreover when I try to edit most of existing classes or add new ones I got red underline that tells
"Implicit super constructor Object() is undefined for default
constructor. Must define an explicit constructor"
So almost no opportunity to use Eclipse in this case. But I noted that such issue is produced just when project uses modules (module-info files introduced in java9). When I import project on jdk 8 (even not installed on system), or even on jdk11 without module-info files, all is fine in Eclipse after import. One visible settings difference in Eclipse is that of when I use old no-module project the Build Path is composed with jre environment 8 and maven dependency items, but when using "module-info" project the Build path contains -module path, and -classpath. So I even do not know where to add jre 11, indeed adding does not resolve issue, just make more errors. So what is the resolution of the case??? What settings to do in Eclipse? Maybe override some project files that maybe inherently created in Intellij IDEA.

Eclipse Oxygen - The project was not built since its build path is incomplete

I just installed Eclipse Oxygen and tried to open an existing project into the workbench but I get this error:
The project was not built since its build path is incomplete. Cannot
find the class file for java.lang.Object. Fix the build path then try
building this project
I tried right clicking on the project - went to Properties - Java Build Path - Libraries - Add Library - JRE System Library and selected Workbench default JRE (jre1.8.0_60).
I then cleaned and rebuilt the project but it then causes more errors to come up like:
ActionBar cannot be resolved to a type
Activity cannot be resolved to a variable
AdapterView cannot be resolved to a type
ArrayAdapter cannot be resolved to a type
Here is what made the error disappear for me:
Close eclipse, open up a terminal window and run:
$ mvn clean eclipse:clean eclipse:eclipse
Are you using Maven? If so,
Right-click on the project, Build Path and go to Configure Build Path
Click the libraries tab. If Maven dependencies are not in the list, you need to add it.
Close the dialog.
To add it:
Right-click on the project, Maven → Disable Maven Nature
Right-click on the project, Configure → Convert to Maven Project.
And then clean
Edit 1:
If that doesn't resolve the issue try right-clicking on your project and select properties. Select Java Build Path → Library tab. Look for a JVM. If it's not there, click to add Library and add the default JVM. If VM is there, click edit and select the default JVM. Hopefully, that works.
Edit 2:
You can also try going into the folder where you have all your projects and delete the .metadata for eclipse (be aware that you'll have to re-import all the projects afterwards! Also all the environment settings you've set would also have to be redone). After it was deleted just import the project again, and hopefully, it works.
In Eclipse, Right click Project -> Maven -> Update Project. It fixed errors in my project.
I'm also using Eclipse Oxygen, migrated from Mars. I faced the same error. I deleted .metadata, .recommenders folders and added projects from archive and issue is solved. I also use Android Studio but i like Eclipse much more.
At my system the Java Runtime JAR file jrt-fs.jar was not found because it was in the wrong directory. This file should be located in the "lib" subfolder. If you installed Java at "C:\Temp\java" the file should be here at C:\Temp\java\lib\jrt-fs.jar .
These are the steps to make jrt-fs.jar available to Eclipse:
Window / Preferences -> the "Preferences" Window opens
Select in the left menu: Java / Installed JREs
Press the [Add...] Button -> A window opens
Select "Standard VM" - The window "JRE Definition" opens.
Enter your path information:
JRE home = "C:\Temp\java"
JRE name = "MyJRE"
Select [Add External JARs...] to link the jrt-fs.jar
JRE system libaries: "C:\Temp\java\lib\jrt-fs.jar"
It worked for me with OpenJDK12 and Eclipse 2019-09 (4.13.0).
Eclipse reported me this error:
The project was not built since its build path is incomplete. Cannot find the class file for java.lang.Object. Fix the build path then try building this project
I had faced this problem. I added the C:\Users\Office 2\android-sdks\platforms\android-19\android.jar to the Java Build Path's Library. And the project started to run again.
The problem occurred due to my carelessness. Yesterday night I was updating the Android SDK, and at the same time I tried to run the project, while the SDK Manager was uncompressing the system image. The Project couldn't start and the error occurred.
I tried all the methods given by others. But nothing worked. It solved when I added the android.jar to the library.
I guessed it that android library is missing. not the Java, when I saw the errors only at the android methods and imports. But when I read the posts, I got confused and wasted some time trying wrong way.
I had faced the same issue and tried different solutions, I have reinstalled my JDK 11 and restarted the machine, after that the issue gets resolved.
I got this out of the blue in a workspace that was working properly before. This problem seems to indicate that the project configuration somehow got corrupted.
Restarting Eclipse didn't help, but in the same vein as the answers dealing with Maven, regenerating the Eclipse project config with:
./gradle eclipse
or
./gradlew eclipse
if you use the wrapper, solved this problem for me.
I have similar issue when importing Spring Boot, jdk 11 (using
inside docker) project to Eclipse 2019 (2021), in Ubuntu, instead when
importing to Inteelij IDEA Community or NetBeans IDEs they do
not produce the same set of after-import errors as in Eclipse.
The Spring Boot is multimodule maven projects and two child
modules give such 2 "problems" in appropriate problems tab:
The project was not built since its build path is incomplete.
Cannot find the class file for java.lang.Object. Fix the build
path then try building this project
Next 2 errors are produced in two classes of aforementioned
maven modules:
The type java.lang.Object cannot be resolved. It is
indirectly referenced from required .class files
Manipulation with adding JDK 11 to submodules buildpath
just leads to the thousands of problems. Also it is
got when I use Eclipse-File-Maven-Update.
Moreover when I try to edit most of existing classes or add new ones
I got red underline that tells
Implicit super constructor Object() is undefined for default
constructor. Must define an explicit constructor
. So almost no opportunity to use Eclipse
even at prebuild stage as docker-compose should run build and
run. Indeed I noted that such issue is produced just when project
also uses modules (module-info files introduced in java9).
When I import project on jdk 8 (even not installed on
system), or even on jdk11 without module-info files all
is fine in Eclipse after import.
Another difference is that of when I use problem old no module
project the Build Path is composed with jre environment 8 and
maven dependency items, but when using
"module-info" project the Build path contains -module path,
and -classpath. So I even do not know where to add jre 11,
indeed adding does not resolve issue, just make more errors.
So what is the resolution of the case??? What settings to do
in Eclipse?

Imported project into Eclipse and shows errors right away

I'm using Eclipse Oxygen.1 release 4.7.1 and I'm running jdk and jre version 9 64-bit on a MacOS Sierra system. I imported a project downloaded from the internet and it's showing 2 errors:
1) The project was not built since its build path is incomplete. Cannot find the class file for java.lang.Object. Fix the build path then try building this project
2) The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class files
Has anyone ever experienced this? It must be a bug with Eclipse because all I did was import the project and it should work fine. I tried several ways to debug like clean the project and remove the JRE system library then add it again and refresh. Also tried restarting Eclipse several times and restarting my computer. Even reinstalled the JDK and re-downloaded and imported the project a few times. Any feedback would be appreciated. Thank you.
This is a rarely occurring bug in eclipse. Here are the steps to solve it, straight from this answer:
Close the project and reopen it.
Clean the project (It will rebuild the buildpath hence reconfiguring with the JDK libraries)
OR
Delete and Re-import the project and if necessary do the above steps again.

java.lang.Object cannot be resolved in Eclipse

When I installed the latest installment in Mac OSX - the Mountain Lion - I experienced some problems getting Eclipse to work I also lost most of my Android developer files (but I still have my projects). I suspect this is due to the choice of removing the /Developer and move the XCode and other Apple developer tools (I placed my Android tools here).
I have now installed the latest version of Eclipse and the problem still seems to be around. There are errors in all my projects and I get an error message prompting:
The type java.lang.Object cannot be resolved. It is indirectly referenced
from required .class files
I tried to check the Java class-path both in Eclipse and in my terminal and these seems to be OK. java and javac both run in my terminal and there is a valid path to the java source files in Eclipse (Under Preferences, Java, Installed JREs). That being said I'm not an expert in Eclipse so there may be that I have misunderstood how this problem ought to be solved. Anyone here with similar problems or who know the cure?
Make sure that you have a valid JRE or JDK defined in the Java Build Path of your project. Right-click on your project, select Properties... and then Java Build Path.
I had this problem moving a Maven project from Eclipse to RAD. I had a JSP file that worked in Tomcat and JBoss, but threw a NullPointerException in WebSphere on the form definition during the compile.
Anyway, after transforming the Maven project into an Ant project (mvn ant:ant), I imported the Ant project into RAD and got this error. The fix:
Open the Java Build Path, selecting the Libraries tab.
Find the JRE System Library and remove it.
Add the JRE System Library.
Goofy, but it works. It must reset some property in a file. I don't know if the problem is the older version of Eclipse or RAD.
After updating my Android SDK to make Appcelerator Titanium happy, I started getting "java.lang.Object cannot be resolved" for my Android projects in (non-Titanium) Eclipse.
I updated all dependencies in Eclipse, and the error healed after a restart of Eclipse.
I had that error almost every time I launched Eclipse for the first time; if I close and then re-open Eclipse, the error is gone.
I found this solution useful, though (I've copied here to protect the link, credit goes to the original author):
In Eclipse go to Windows -> Preferences -> Java -> Installed JREs.
Select the currently active JRE/JDK and press the Edit button.
Select the rt.jar and change its position in the list of JRE system libraries (e.g. press the Up button once).
Confirm all changes, clean and rebuild the workspace.
The next time you face the problem reposition the rt.jar again (or reset the order by pressing the Restore Default button).
please select your installed system jre version from java build path.
Try the following and problem will go away
Close the project and reopen it.
Clean the project (It will rebuild the buildpath hence reconfiguring with the JDK libraries)
OR
Delete and Re-import the project and if necessary do the above steps again.
This is an annoying Eclipse Bug which seems to bite now and then. See http://dev-answers.blogspot.de/2009/06/eclipse-build-errors-javalangobject.html for a possible solution, otherwise try the following;
Close the project and reopen it.
Clean the project (It will rebuild the buildpath hence reconfiguring with the JDK libraries)
OR
Delete and Re-import the project and if necessary do the above steps again.
The better cure is to try NetBeans instead of Eclipse
I got this error and what I had to do was remove the JRE from the Window/Preferences/Java/Installed JREs and re-add it. This somehow cleared up eclipse's cache and rebuilt the project successfully. To get rid of the error in the file-editor I also had to close it and open the file once again.
My problem was that I had in Eclipse: Window / Preferences... and then in the tree on the left Java / Installed JREs: C:\Program Files\Java\jre7
I changed to: c:\Program Files (x86)\Java\jre7
It solved my problem.
I had the same issue and none of the above solutions worked for me.
Then I realized than the library (libs) folder was missing in the project. Once i added the libs folder and the corresponding Jar file, the issue was resolved..
If your project specific (or if not applicable, workspace default) JDK/JRE is being referenced correctly and you've just begun to get this issue out of the blue: restart Eclipse.
Unfortunately, "restart Eclipse" is one of the standard troubleshooting steps when a project won't build. Eclipse even has a dedicated entry under the File menu.
I had to add the JDK under the build path. After adding the correct build path it worked.
I just had to restart eclipse, and the error went away. Strange.
I solved this by pointing my eclipse to the jre available in jdk.
This error caused by invalid sdk is pointing in your project.properties file of your project.
project.properties -> target=android-19 . change to version which is installed in your eclipse.The error will be gone.
I had the same issue after moving from JRE7 to JDK7. Finally I had to remove the JRE7 configuration from the Eclipse preferences and then add the following two lines to the eclipse.ini file.
-vm
C:\Program Files\Java\jdk1.7.0_55\bin\javaw.exe
I had this problem, and I understood that Eclipse has automatically imported a core reference, instead of the reference for the project I needed.
Deleted the import, and rearranged it, and everything worked fine.
Same problem facing Me
Project->properties->Android
And select the api level and also go in java build path and check some external jar file path if we already add in it.update the jar file path
On "The type java.lang.Object cannot be resolved. It is indirectly referenced
from required .class files":
I found my project had 2 meta-inf.java files in 2 different directories with the same 'module ' on line one (a copy/paste error).
Once this was corrected, I cleared the meta-inf.java file with the issue, rebuilding it line by line, guided by Eclipse, until I had a working module configuration.

IDEA JetBrains IntelliJ - Compile error on 'make' but fine when compiled using Maven and no errors reported by IntelliJ in the class file

So I have a maven module (module-A) in IntelliJ. I recently moved some classes from it into another new maven module (module-B) and added a dependency to it. Once I had done this I also modified the signature of a method of one of the moved classes (now in module-B).
I re-imported the poms so that IntelliJ would pick up the dependency changes and ensured all Java imports for the affected files were correct again. Now when I attempt to run my webapp (which depends on the two modules) I get a compile error in a class in module-A calling the modified method of the class in module-B.
The error message is basically saying that that method doesn't exist but believes the old method still exists! I click on the 'make' error and it takes me to the line in a class in module-A calling the modified method...the weird thing is, IntelliJ knows it is fine in the file. i.e. The method is not underlined in red like a compile error would normally be, but the class file name is :(
I compiled it from the command line using 'mvn install' (having also installed module-B) and it is all successful. I have deleted the classes directory in the target of both module-A and module-B and also invalidated IntelliJ's caches and restarted...still happening...any ideas?
I found out that this might help:
File -> Invalidate Caches
Maven Projects -> Reimport should help.
I spent a few hours on this same issue. All of the cleans in the world didn't help.
I deleted my out and target directory in my project and recompiled - that cleared it.
Edit: There is also a magic feature under the file menu: "Invalidate Caches / Restart" This fixes a bunch of "intellij is confused" problems.
Change "Java Compiler" setting in IDEA (User compiler javac in-process) to fix the problem.
Try to mvn clean your projects and mvn install your project B.
The maven integration with intelliJ is kind of buggy when you use the make command directly provided by Intellij. You should directly use the mvn commands, or start them from the maven panel.
I ran across a very similar problem that was driving me insane.
My code would compile fine with the ant task I normally run, but it would not build in IntelliJ, complaining about "Cannot Find Symbol blah blah"
Turns out, you can add "Excluded" files for the compiler. My file somehow got added to that list.
This list is located in File > Settings > Compiler > Excludes (IntelliJ 13)
Following steps should fix this problem :
delete .IntelliJIdea12 / .IdeaIC12 older under c:/user/.../
Invalidate Intelli's cache: File > Invalidate Caches.
This re-indexes your workspace on start-up and also clears your local history. Before you do this, commit or back up all your uncommitted changes.
Once your workspace is back after indexing, do a maven clean install.
when the build is successful, click on Maven Re-imports
This worked for me, I think it should work for others too with a similar problem.
So just stated it up this morning and it's all working!
Last night what I did do was open a new project (intelliJ project) from module-A's and module-B's parent pom and successfully got it to build, possibly doing that and then opening my original project again fixed it somehow...very annoying though
The behavior I see is similar to the one described by the original author.
Error markers show up on the right side of the editor in Intellij 14 and less so in 13.
This happens also if using Scala instead of Java and using SBT instead of Maven.
Also noticed this occurs after the second project is loaded. The first is always fine.
(After much trial and error) Figured it might be caused by Intellij's internal caches becoming somehow corrupt. "Invalidate caches" worked sometime and sometimes did not.
I work with a number of projects using Play! Framework and they use different versions of Scala and lots of dependencies.
I hypothesized the caches become corrupt because the internal key Intellij uses is not good enough to handle situations when the same class, loaded multiple times in different jars, has different signatures, and this results in the editor errors while external builds work fine.
Then the "Changing Ivy Cache Location for sbt projects in IntelliJ IDEA?" post gave the idea to segregate the ivy cache SBT and Intellij use in the hope that the ivy path is part of the internal cache key.
Paul Phillips of TypeSafe provide the "SBT extras" tooling and here I found a way to instruct SBT to use a project based ivy home, cache and SBT boot:
https: //raw.githubusercontent.com/paulp/sbt-extras/master/sbt
declare -r noshare_opts="-Dsbt.global.base=project/.sbtboot -Dsbt.boot.directory=project/.boot -Dsbt.ivy.home=project/.ivy"
How to configure Intellij
: see http://content.screencast.com/users/SemanticBeeng/folders/Snagit/media/ec8ec491-6d0c-4691-9598-916a63ba65ef/12.02.2014-08.59.png
Then did the same for the external SBT build to work in sync
: see http://content.screencast.com/users/SemanticBeeng/folders/Snagit/media/dcb287c4-200f-47f3-a937-42865675a22b/12.02.2014-09.01.png
Finally got rid of the user home based .ivy2 and all the contents.
To be sure Intellij does not use this folder I made it readonly.
This was a mistake. Intellij seems to silently fail resolve dependencies if you do this.
This solved the errors and believe they will not come back. :-)
If Intellij guys hear this: please test your releases (Scala, SBT, editor) with all the Play Framework templates from TypeSafe. The problem becomes apparent quickly this way.
I just had a similar issue that was driving me insane. I had done all the other things mentioned in the answers above because I have used Intellij forever, but none worked. In the end I found out that in the maven projects portion of Intellij, one of my modules had been marked "ignore" a simple unignore command from the context menu did the trick.
In my case, I had manually marked a directory as "Test Sources Root" but IDEA marked it on a parent Maven project. Unmarking it in File->Project structure...->Modules fixed the problem.
This could happen if you are using different version of java while building outside IntelljJ. My IntelliJ had java10 and I was using java8 while building at terminal. Changing java version to IntelliJ fixed this issue for me.
I had a very similar behavior. Running (Scala-)tests would always fail due to errors in unrelated java classes during the 'make' step.
It turned out, I had included a 'global' SDK library that collided with one of the dependencies from the project. A proper helpful error message only showed up after I deleted the 'make' step from the test.
I then deleted the duplicate library, re-added the make step to the test and everything is now working fine.
I ran into this problem today after upgrading from 12 to 13.
Later I fixed issue as I used the same name for Project and Module and looks Intellij allows this but cannot handle it correctly.
No idea why setting will impact the compilation, although there is no error in java editor. Should be a bug in version 13.
I was facing a similar issue after upgrading from IntelliJ 12 to 13. After multiple uninstalls and re-installs (of multiple intelliJ versions), numerous cleans and .m2 repository clearing, I finally figured out what my issue was.
In my intelliJ settings, the repositories mentioned in my main POM file could not be connected to. this was in turn due and alternate repository that was mentioned as a part of my pom file.
Once the POM was made to point to the correct repository, all my classes had their compilation issues resolved.
To check if your repositories are being connected to, go to File -> Settings -> Maven -> Repositories
Here, your indexed maven repositories should be connected to successfully. If they are not, then intelliJ will not be able to resolve most 3rd party and module dependencies.
I'm embarrassed to say, but we also had this problem, but it was due to a mistake in our package name.
When creating the packages for a new project I accidentally created a package called "org.package".
My project then had a directory structure like:
/src/main/java/org.package/
Which caused all sorts of havoc with IntilliJ.
Once the correct folder structure was created on the file system, IntelliJ worked great.
/src/main/java/org/package/
Note the difference in /org.package/ vs /org/package/
The fix was i made it javac instead of Ajc and i put 1.8 of course according to your jdk version.
for some reason when i invalidate and restart intellij it was set to be the default !
my version is
This happened to me...what fixed it was realising there was an extra main.iml file in the source directory. Deleting that instantly made the compile errors go away.
None of the above answers worked for me.
In my case, I had to finally create an explicit Maven Run Configuration for the module (with Command Line as "clean install") and then run it.
It is in Run > Edit Configurations
close the project
go-to the project folder and delete idea project file and .iws file
run mvn idea:idea
restart the project.
seems idea keeping the old project dependencies without cleaning even though we run file -> invalidate caches
Setting the proper Java SDK solves the issue
Right click on the project and select "Open Module Settings"
Check if you have the right Java SDK under platform settings
Check the SDK under Modules
Rebuild the project from "Build" menu
Delete the installation directory.
Remove the following directories:
~/.config/JetBrains/
~/.cache/JetBrains/
~/.local/share/JetBrains/
This will remove each and every configuration plus installation of jetbrains tools, be it IDEA, goland,etc.
Now install everything from scratch.
That's the only way it worked for me

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