Jdk.compiler does not “opens com.sun.tools.javac.processing” to unnamed module

Explanation:

When using the JDK compiler (jdk.compiler), you may encounter the error message “does not ‘opens com.sun.tools.javac.processing’ to unnamed module”. This error occurs when you are trying to access a package or module that is not accessible by the current module.

In Java, classes and packages are organized into modules. A module is a collection of packages that are grouped together and can be referenced collectively. When a module wants to make its packages accessible to other modules, it needs to explicitly declare the packages it “opens”.

The error message you mentioned specifically indicates that the com.sun.tools.javac.processing package is not accessible to the current module (possibly an unnamed module). This package is part of the internal implementation of the Java compiler and is typically not intended for direct usage by external modules.

Example:

Let’s consider an example where you have a module named “myModule” and you want to access the com.sun.tools.javac.processing package from within your module.

To resolve the error and make the com.sun.tools.javac.processing package accessible to your module, you need to explicitly open the package in your module declaration.

        
        module myModule {
            opens com.sun.tools.javac.processing;
        }
        
    

By declaring “opens com.sun.tools.javac.processing;”, you are granting access to this package from your module. This will allow the classes within your module to reference and use the classes from the com.sun.tools.javac.processing package.

However, it is important to note that accessing internal implementation packages like com.sun.tools.javac.processing is generally discouraged. These packages are subject to change and may vary between different JDK implementations. It is usually recommended to find alternate ways to achieve your desired functionality without directly relying on internal packages.