qdox | full extractor of Java class | Aspect Oriented library

This might have to do with you not using Generics with your java Collections

As of Spring Boot 2.4, JUnit 5’s vintage engine has been removed from spring-boot-starter-test. If we still want to write tests using JUnit 4, we need to add the following Maven dependency:

It looks like a JDK bug. See the same problem in this thread: mac m1 Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again

I think it is worth reporting to https://bugreport.java.com/bugreport/crash.jsp

As a workaround try using a different JDK for the project.

There are a bunch of dependency analysers available, but if you are using a recent JDK, jdeps (part of the JDK since 8) might be sufficient for your needs.

For example:

When you start a program like java, the operating system creates a "process". A process is the representation of a live, running program. The process concept is what allows you to run several copies of a program at the same time. Each process has its own private memory space and system resources like open files or network connections. Each process can load a different set of dynamically linked libraries. With Java, much of the jvm is implemented in shared libraries, which the launcher program "java" loads in at run time.

The details are OS dependent and become complicated fast.

One of the things that happen when the process is started is that the executable file is mapped into memory. The CPU cannot execute instructions that are on disk or other external storage, so the program "text" has to be copied from disk into main memory first. Mapping the file into memory simplifies this and makes it more efficient: If the CPU needs to access a memory location that's not actually in RAM, the memory manager unit (MMU) issues a "page fault". The page fault causes data to be loaded into RAM. This is more efficient than simply copying the program text into RAM (what if not all text is needed all the time) and also simplifies the overall system (the virtual memory system is already needed for other OS features)

The problem is the Java version number. In the error text it says "Fatal error compiling: invalid target release: 12".
For Heroku, you need to create the file "system.properties" in the root of the project, write "java.runtime.version = 12" in it.

The system.properties file indicates which version of Java is being used. Heroku supports many different versions of Java and version "12" is not the default version. Details in the documentation: https://devcenter.heroku.com/articles/getting-started-with-java#declare-app-dependencies https://devcenter.heroku.com/articles/java-support#specifying-a-java-version

You have Windows Defender enabled by default. Disabling the firewall is known to help with similar issues, see this comment:

• Go to Windows Defender settings
• Then go to firewall & network protection
• Disable private network (active)

Your firewall is probably configured incorrectly as it should not block loopback interface (localhost) connections by default.

The stacktrace indicates that the issue is networking related:

I've just found a workaround for problems with using jaxb2-maven-plugin with Java 11. It consists of adding extra dependencies in pom.xml and adding an extra, dummy XSD file to the project, next to proper XSD files. I've put it altogether in my blog-post here: https://artofcode.wordpress.com/2019/02/26/jaxb2-maven-plugin-2-4-and-java-11/

There is some common firewall trouble using IDEA with windows because it uses localhost communication with compiler process, So check your firewall setting for IDEA and make it full access.

Some reference:

• Failed to create a child event loop
• IntelliJ IDEA do conflict with firewall?

Do the record for someone may suffer the same problem.