Play! Framework + Java - java

when I try to create a new play app and then launch my play application (without modifying any code) locally I get the following error:
http://cl.ly/image/1x311s1w3S2w
which says I have a continuation error. However I cannot fix it as I have other older play projects which I can still launch and they still work perfectly. My java version in eclipse 1.7 and my play version is 1.2.5.
I realise now that my JVM is 1.8, will this make a difference? Although then why do they older apps still work, when they are also written using 1.7.
Any help at all would be great, thanks!

I don't think the JVM version would be the issue. The issue is with the loading of your class ContinuationEnhancer. Try replacing the jar of that class.

Related

Problems with Java on Visual Studio Code

I only have a Raspberry Pi to practice, and Visual Studio Code runs smoothly on it for many languages I've tried, but I can't seem to run Java on it. I installed the Extension Pack for Java, but when I create a Java Project and try to run it, the Debugger keeps loading and doesn't start at all. I tried uninstalling/reinstalling the Extension Pack and the Debugger, but without success. I know the solution might be obvious, but I tried googling it and found nothing.
Found out that the latest version of the extension "Language Support for Java by RedHat" wasn't working properly on my VSCode. I installed version 1.0.0 and it loaded everything and now I can run Java smoothly.

VSCode Java Debugger throwing unknown error

I had to re-install VSCode on my machine after an issue I was having, and after having done so, I can no longer run my Spring application. There is no error code, thrown, I can't find it in the VSCode logs, and the dialog isn't even copyable.
This is the error dialog displayed:
'void
org.eclipse.jdi.internal.connect.ConnectorImpl$StringArgumentImpl.<init>(org.eclipse.jdi.i...
java.lang.String,java.lang.String, java.lang.String, boolean)'
The launch.json configuration was auto-generated by Spring Initializr, and previously worked. No changes have been made to my JDK or my pom.xml.
I also created a new test app and it had the same problem, so it's not limited to this app or workspace.
Any ideas of what is going on here? (I tried googling the... error... but got not anything helpful)
You need update "Debugger for Java" extension to 0.33.1, which has fixed it.
See https://github.com/microsoft/vscode-java-debug/issues/995
Update: "Debugger for Java" 0.33.1 also requires your VS Code version to be 1.55.0 and above.
Going to go ahead and answer this, as I've fixed it.
I had the latest versions of both VSCode and the Java Debugger extension (I had just re-installed them both).
I wound up re-installing Windows entirely (spring cleaning), and now it's working again.
This error occurs when we don't have the latest version of 'debugger for java' extension. We have to update the version to v0.33.1. In order to update to the latest version of extension you need to have the latest version of VSCode(1.55.0).
You can get the latest version of VSCode from here : https://code.visualstudio.com/
Download the .deb package and then open the file directory in terminal. Use 'dpkg -i filename.deb' command to install the latest version. Restart the VSCode and update the extension.
Note, that after updating VSCode, the extensions might need updating and another restart of VSCode before both VSCode and extensions are running latest versions.

Libgdx could not determine java version 11.0.1

I tried everything I installed every possible Java file a million times I installed the newest gradle version but it continues to show this error. I'm on Mac. Please help thanks
IF you do not want to develop for Android Java 11 works fine libgdx.
You have to change some things before everything builds and runs.
Here's what I did to get my project working.
My context Mac OSX 10.14 and openJDK 11.0.2, new project, Desktop launcher and a bunch of Extensions (not important).
The error you get about not being able to find java 11.0.x comes from gradle. Java 11 is only supported since gradle 5. In order to use gradle 5 instead of 4.6 the generated project is configured with, go to <project-dir>/gradle/wrapper/gradle-wrapper.properties and change distributionUrl=https\://services.gradle.org/distributions/gradle-4.6-all.zip into distributionUrl=https\://services.gradle.org/distributions/gradle-5.0-all.zip.
That resolves the java 11 error just to confront you with a new error Could not get unknown property 'classesDir' for main classes of type org.gradle.api.internal.tasks.DefaultSourceSetOutput.
To get rid of that, open <project-dir>/desktop/build.gradle and change line 27 (might be different for you)
from files(sourceSets.main.output.classesDir) into
from files(sourceSets.main.output.classesDirs)
thats classesDir into classesDirs
This should resolve all build errors and you're good to go.
I am strongly recommend to use Java version not greater than 8. It is many incompatibility issues I faced just on 9 version of JDK in Android Dev environment.
Uninstall all java you have, use this article, because it is not as such easy without knowledge: https://www.java.com/en/download/help/mac_uninstall_java.xml
After download the 8th version from here: https://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
I did same some time ago and all problems left

Running java application on different JDK from original

I have developed a Java Application in Eclipse using JDK 1.7.0, the application runs and everything works as expected.
Now I would like to send the application to a colleague of mine who is using a different version of the JDK. He is using 1.6.x.
I am not interested in him opening up the application and debugging through it in Eclipse. I would only like him to run it. If I make a runnable .jar of the application and send that to him, would it work even though he has a different JDK installed on his machine?
Thank You.
You need to compile it using JDK 1.6 (or lower). Provided your code doesn't use features from Java 7, you won't have to change anything in your sources
It would work if your colleague had a newer JRE than the JDK you used to compile it. All versions of JRE are backwards-compatible with all class files built with previous versions, but the opposite can clearly not work because new versions introduce new features. Your colleague will get an UnsupportedClassVersionError.
However, it is easy to set up in Eclipse the target class version for your project: go to Project Properties, Java Compiler, and under JDK Compliance choose the version 1.6.
Needless to say, this will fail if your source code uses any features or library calls which the version 6 does not support.

does sysdeo tomcat plugin for eclipse add value to helios?

am developing a simple web app using jsps and servlets for tomcat 5.5.
Currently using the Eclipse Helios and Dynamic Web Application Project.
For some reason it is a nightmare. We spent 4 hours today trying to deploy a servlet to tomcat. We kept getting errors like
"java.lang.UnsupportedClassVersionError: Bad version number in .class file"
we played around with everything trying to set the build compatibility to what tomcat had but couldn't make the stupid thing work. (Yes it is possible we're incompetent. any suggestions on what we can try looking at are apprecieated)
My friend recalls from long time ago that he used this plugin
eclipsetotale_tomcatPlugin
in order to create a "tomcat project". My question is, does sysdeo tomcat plugin add any features that aren't already available in helios?
thanks
Not sure about sysdeo, but your error seems similar to bug 116713:
If your default JRE is set to 1.4.2 and you have a Web project targetting
Tomcat 5.5 (dynamic Web module version 2.4 and Java 5.0), when you tried to run
a main program, you'll get the error (you mention).
What is your default JRE set for your project?
This scenario happens when the JVM running the code is older than the one the compiler generated code for.
Have you considered simply running Tomcat under Java 6? If that is not an option, please edit your question to include this and any other restrictions on this project.
We used to get that error often when we had Java version issues. Eclipse environment and Windows environment (java_home and path variables typically) are easy to overlook.
Also, you can use javap -v Foo in same directory as Foo.class to find out its version.
Just use the Eclipse IDE for Java EE Developers, 206 MB edition of Eclipse. It has Tomcat and other webserver support built-in by default. Works like a charm!
Sysdeo is an old, as far as I know obsolete, plugin.

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