Error: package xxx is declared in module java.base, which does not export it

Symptom

When JDK 11 or a later version is used, the following error information is displayed:

java: package xxx is not visible
  (package xxx is declared in module java.base, which does not export it)

Possible Causes

Startup parameters are not added to the pom.xml or build.gradle file.

Troubleshooting Procedure

Add compilation startup parameters to the pom.xml or build.gradle file.

For example, add compilation startup parameters to the pom.xml file.

<build>
    <plugins>
        <plugin>
            <!-- Compilation plugin -->
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <version>3.1</version>
            <configuration>
                <source>${java.version}</source>
                <target>${java.version}</target>
                <encoding>${project.build.sourceEncoding}</encoding>
                <compilerArgs>
                    <arg>--add-exports</arg>
                    <arg>java.base/sun.util.calendar=ALL-UNNAMED</arg>
                </compilerArgs>
            </configuration>
        </plugin>
    </plugins>
</build>

Parent topic: FAQs