Could not find or load main class - VS Code

Question

I created a new java project (with the option Create Java Project), and When I click the run button (marked with the red circle), it gives me the error Could not find or load main class.

When I run the program from the run option above the main(marked with the green circle), it works and doesn't show me the error.

How can I fix it?

This is the .classpath file:

<?xml version="1.0" encoding="UTF-8"?>
<classpath>
    <classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.8"/>
    <classpathentry kind="src" path="src"/>
    <classpathentry kind="output" path="bin"/>
</classpath>

Answer 1

This is a known issue https://github.com/microsoft/vscode-java-debug/issues/606, https://github.com/eclipse/eclipse.jdt.ls/issues/1137, which caused the new package not recognized during building workspace. It's expected to be fixed in vscode-java Middle October release.

Current workaround is reload VS Code window, or F1 ->Clean the java language server workspace.

Answer 2

i think you install the Code Runner Extension,so you have a Run icon in the upper right-hand corner，you could try to uninstall it,

then F1 ->Clean the java language server workspace.,run your code with F5 or the Run above your Main method

Answer 3

Try editing your .classpath file to show it where your main class is.

An easier, but much more jank method, is to move your .java file to the root of your project directory to help vscode find it.

Answer 4

Install java extension package and try running it by CTRL + F5. Works well by the time it gets fixed.