package sun.net.www.protocol.https is declared in module java.base, which does not export it

Issue

I am trying to build a java project using gradle6.6 and open jre 11.0.2, in eclipse 03-2020. I am facing compilation issue, while building my project which uses the classes from jrt-fs.jar; e.g.'sun.net.www.protocol.http.Handler', which is in open jre 11.

public class Manager extends sun.net.www.protocol.https.Handler{
(package sun.net.www.protocol.https is declared in module java.base, which 
 does not export it)
 1 error
 FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':compileJava'.
> Compilation failed; see the compiler error output for details.

Following is my build.gradle:

apply plugin: 'java'
apply plugin: 'application'

allprojects {
      apply plugin: 'java'
      sourceCompatibility = '11.0.2'
      targetCompatibility = JavaVersion.VERSION_11
}

repositories {
      mavenCentral()
}

dependencies {
      compile fileTree(dir: 'lib', include: '*.jar')
      compile group: 'org.hamcrest',            name: 'hamcrest-all',     version: '1.3'
      compile group: 'junit',                   name: 'junit',            version: '4.10'
      compile group: 'jmock',                   name: 'jmock',            version: '1.0.1'
      compile group: 'com.google.code.findbugs',name: 'findbugs',         version: '1.3.9'
      compile group: 'cglib',                   name: 'cglib',            version: '2.1'    
      testCompile group: 'junit',               name: 'junit',            version: '4.10'
 }

also, how can I avoid building the test classes, through gradle?

Solution

As @dave_thompson_085 suggested, Issue is due to modular restriction (JDK-1.9 onwards) on sun.net.* packages , as they are internal to JDK. The above packages are accessible in JDK -1.8. We need to fix our code

Answered By - Soumali Chatterjee