After first trying to start Eclipse without any parameters to specify the Java VM, I got an error message saying it couldn't find a Java VM called javaw.exe inside the Eclipse folder, so I found where Java was installed and specified that location as the parameter in the shortcut's target. Now I get a different error, Java was started but returned exit code=13.
This can happen when a system has more than one JVM installed, as is often the case on Windows 64-bit (for example, the JRE download page uses the bit-ness of the browser to determine what bit-ness download to offer you, and many people use(d) 32-bit browsers even though they run 64-bit Windows).
The best way to fix this, assuming you do in fact have 64-bit JRE or JDK on your system, is to specify in eclipse.ini exactly which JVM you want it to use. The instructions are detailed in the Eclipse wiki page, but basically you have to specify the -vm option in the ini file - make sure to read the wiki page carefully as the format is very specific.
Specifying the JVM path in eclipse.ini is strongly recommended because doing so isolates Eclipse from any potential changes to your system PATH that some program installers might make (I'm talking to you, Oracle!).
If you are on a 64-bit machine, then you can install the 64-bit JDK and uninstall the 32-bit one. For instance on Windows 10, just go to Settings and under Apps, you will find Java. Click on it and you will find all the different versions. Now you can select which one to uninstall.
So the solution is quite straightforward: You need to synchronise them by updating either one. This shall happen when downloading Oracle Fusion middleware and Eclipse expects a 32-bit environment while your JRE is 64-bit and your JAVA home is pointing to a 64-bit JDK.
Changing environment variables, etc. did not help. So I tried to remove the Java Update 8, but that too did not help. Downloading and installing the 64-bit version of Java 8 SDK fixed my problem. I hope this helps.
Please check whether you have set two JAVA paths in the Environment Variable section. If you already installed two versions of the JDK, it might be, then double check you have put PATH for Java like below.
I have no idea why, but from today Eclipse doesn't compile .java files into .class. I press the "Run" button and Eclipse only tries to run the program rather then compiles it first, so i get this error all the time:
This problem happens when "for some reasons" your project is corrupted and has a red icon near the project's name in Eclipse. The solution is to save the project's folder, delete the project in Eclipse, than create the project again in Eclipse coping all the previous files saved.
When I have had this exact same problem, its cause has always been the same and the solution has worked 100% of the time for me. It's caused by a missing jar file in the project's Java build path and it's indicated by a red exclamation point decoration on the project icon. To fix the problem, go to ProjectPropertiesJava Build Path, click on the Libraries tab and either remove or fix the path for all missing jar files. If your project is configured to rebuild automatically, it should start a build as soon as you apply your changes.
The folder is found on Project Properties -> Java Build Path -> Default Output Folder. It can differ from general output folder name found under Eclipse Preferences. If this output folder cannot be erased for some reason (for instance, on Windows, when a shell is opened on this location), the project is marked as corrupted (as Marco Micheli describes) and the classes then are not built.
Yes I was facing this issue. Coz Eclipse cannot build the project for Build Path error. Check that your external jar files is not showing any error. Delete the Jar file which one is missing or which one is showing re color. delete that one. add a fresh one from the correct path or location. if all the error are gone. then in the project bin folder one class file will be created and then could not load main class error will be removed too.
I had problem in eclipse for load module not found and no class file was getting created.Solution: Go to Create New Project > Under JRE section Choose Use project Specific JRE.Now Class files are created.
Just restart your machine.Its weird but it helps we had loads of problems this type in our company for unknown yet reason. Always restarting the machine helped.It was normally encountered while trying to run Junit tests and it could not find a class even when the Run configuration was pointed to /bin.
I encountered a similar problem: previously compiled and running java files couldn't run anymore. Eclipse showed "couldn't find class xxxx". When I checked bin folder, the previous .class files were gone. That's why Eclipse couldn't run the files, NOT because of errors in files. I don't know why it can't just re-compile the file, and why the .class file gone missing in the first place.
But I found a solution:
Simply create a dummy java file in the same package (without doing anything just create), then run it. Then magically all previous .class files came back. And I can run those files as before.
This is probably a rare event but I declared a servlet with annotations and left off the "/" before the servlet mapping name. I spent over an hour chasing my tail, installing new servers, thinking I might even need to re-install my IDE and it was this simple error! Every time I tried to load any page from my Dynamic Web Project I got a 404 error. I could not even load a plain vanilla html page. There really needs to be better error logging with the IDE and Server interaction as there was zero indication of the error and my servlet was never called at the start of my web app. Hope this helps save someone else some frustration. Always name your servlet with a / slash like /myServlet never just myServlet.
I tried many different potential solutions: cleaning, rebuilding, removing, re importing, Update Maven Project and nothing. I still couldn't run my app from Eclipse. In my case the reason was that I was running Eclipse using openjdk-11 while my project was in Java 8. After I've reconfigured Eclipse to be ran from Java 8 everything started to work (in eclipse.ini).
I'll explain my solution to this problem: "eclipse not compiling java files into class files". I'm using Eclipse version '2020-03 (4.15.0)'. I have a project that is dependent on a java project. For the dependent project, I was not able to export a jar file containing the compiles classes and resources. To be more precise, the exported jar file did not contain any class files. The output bin folder for the project is empty after doing a project build. In examining the console output when I tried to build all projects indicated that the build failed because the dependent project was missing. In looking at one of the log outputs, I saw something indicating that the build failed because some eclipse class was missing.
One of the things I tried was to do an eclipse update. Eclipse offered up the list of changes and I tried to apply them, but the update failed. I tried to update several times but they all failed. Looking more carefully at the offered up list of updates I noticed that one of the suggested update involved "deleting" Java Development Tools. That line had an warning indicating that the entire feature could not be deleted due to other dependencies and that only the non dependent features would be deleted. Doesn't that sound suspicious. Why was the update trying to delete Java Development Tools? My speculation is that something got deleted from the Java Development tool that was causing the build process to fail. The missing class I saw earlier also suspiciously sounds like it might be part of the Java Development Tools feature.
So what I did to solve the problem was to reinstall eclipse. I used the eclipse loader application to do the reinstall. (Note, I did not uninstall it first). After the reinstall, the dependent project was able to produce classes, and things once again worked as they should.
I opened one of the file in Intellij and this problem happened to me as well. Eclipse couldn't identify new files and lost the properties of the file that is opened by other IDEs. (I don't know why) Here's the steps I fixed it, hope it works for you.
First of all are seeing a cross sign near your application in project explorer?If yes then export your project as a war, and check if your class is present in the classes directory ( "path_to_war\NoteTaking.war\WEB-INF\classes). If you don't have the class file there then we need to clean the project. One the top menu of eclipse go to project and clean. After that cross sign should disappear from application and you should be able to see in classes directoryalso.
There would be the case : if you have opened project explorer in eclipse then it may not show you classes generated under /**/build/classes, in such case open Navigator view of that project and check build directory under the same project.
It seems like this should be a simple task, with the options in the Preferences menu for different JREs and the ability to set different compiler and build paths per project. However, it also seems to simply not work.
For example, I have my JAVA_HOME set to a jre for Java 1.6. It's still not clear to me how Eclipse uses this, but it appears to be defaulting to this and not taking the project overrides. I have also installed Java 1.5, and added a JRE for this in eclipse in the Java->Installed JREs section.
In my project, I've set the compiler compliance level to 1.5. In the build path for the project, I've added the System Library for the Java 1.5 JRE. However, I'm getting compile errors for a class that implements PreparedStatement for not implementing abstract methods that only exist in Java 1.6 PreparedStatement. Specifically, the methods
Strangely enough, it worked when we were compiling it against Java 1.4, which it was originally written for. We added the JREs for Java 1.4 and referenced that system library in the project, and set the project's compiler level to 1.4, and it works fine. But when I do the same changes to try to point to Java 1.5, it instead uses 1.6.
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