IllegalAccessException when accessing ZoneInfo via JSF/EL with JDK 17

Question

While porting a big JEE8 application to Java 17, I stumbled upon an IllegalAccessException when rendering a simple EL expression: #{myWarBean.defaultTZ.rawOffset}. I managed to reproduce the problem in a SSCCE on github. When you run the application on Wildfly application server (I'm using 26.1.1.Final), you get the following stacktrace:

SEVERE [javax.enterprise.resource.webcontainer.jsf.application] (default task-1) Error Rendering View[/index.xhtml]: javax.el.ELException: /index.xhtml @23,74 value="raw offset=#{myWarBean.defaultTZ.rawOffset}": java.lang.IllegalAccessException: class javax.el.BeanELResolver cannot access class sun.util.calendar.ZoneInfo (in module java.base) because module java.base does not export sun.util.calendar to unnamed module @6a1cb0de
    at [email protected]//com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:77)
    at [email protected]//javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:194)
    at [email protected]//javax.faces.component.ComponentStateHelper.eval(ComponentStateHelper.java:181)
    at [email protected]//javax.faces.component.UIOutput.getValue(UIOutput.java:140)
    at [email protected]//com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getValue(HtmlBasicInputRenderer.java:198)
    at [email protected]//com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getCurrentValue(HtmlBasicRenderer.java:328)
    at [email protected]//com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeEnd(HtmlBasicRenderer.java:143)
    at [email protected]//javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:600)
    at [email protected]//com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeRecursive(HtmlBasicRenderer.java:286)
    at [email protected]//com.sun.faces.renderkit.html_basic.GroupRenderer.encodeChildren(GroupRenderer.java:90)
    at [email protected]//javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:571)
    at [email protected]//javax.faces.component.UIComponent.encodeAll(UIComponent.java:1648)
    at [email protected]//javax.faces.component.UIComponent.encodeAll(UIComponent.java:1651)
    at [email protected]//javax.faces.component.UIComponent.encodeAll(UIComponent.java:1651)
    at [email protected]//com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:461)
    [...]
Caused by: javax.el.ELException: java.lang.IllegalAccessException: class javax.el.BeanELResolver cannot access class sun.util.calendar.ZoneInfo (in module java.base) because module java.base does not export sun.util.calendar to unnamed module @6a1cb0de
    at [email protected]//javax.el.BeanELResolver.getValue(BeanELResolver.java:193)
    at [email protected]//com.sun.faces.el.DemuxCompositeELResolver._getValue(DemuxCompositeELResolver.java:156)
    at [email protected]//com.sun.faces.el.DemuxCompositeELResolver.getValue(DemuxCompositeELResolver.java:184)
    at [email protected]//com.sun.el.parser.AstValue.getValue(AstValue.java:114)
    at [email protected]//com.sun.el.parser.AstValue.getValue(AstValue.java:177)
    at [email protected]//com.sun.el.parser.AstDeferredExpression.getValue(AstDeferredExpression.java:39)
    at [email protected]//com.sun.el.parser.AstCompositeExpression.getValue(AstCompositeExpression.java:44)
    at [email protected]//com.sun.el.ValueExpressionImpl.getValue(ValueExpressionImpl.java:183)
    at [email protected]//org.jboss.weld.module.web.el.WeldValueExpression.getValue(WeldValueExpression.java:50)
    at [email protected]//org.jboss.weld.module.web.el.WeldValueExpression.getValue(WeldValueExpression.java:50)
    at [email protected]//com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:73)
    ... 73 more
Caused by: java.lang.IllegalAccessException: class javax.el.BeanELResolver cannot access class sun.util.calendar.ZoneInfo (in module java.base) because module java.base does not export sun.util.calendar to unnamed module @6a1cb0de
    at java.base/jdk.internal.reflect.Reflection.newIllegalAccessException(Reflection.java:392)
    at java.base/java.lang.reflect.AccessibleObject.checkAccess(AccessibleObject.java:674)
    at java.base/java.lang.reflect.Method.invoke(Method.java:560)
    at [email protected]//javax.el.BeanELResolver.getValue(BeanELResolver.java:186)
    ... 83 more

It seems, the problem is the EL expression accessing a java.util.TimeZone. The TimeZone class uses sun.util.calendar.ZoneInfo internally. And it seems this is not legal any more.

This only happens with Java 17. When running in Java 11, this all works fine.

I can workaround the exception by adding the following arguments when starting wildfly:

--add-exports=java.base/sun.util.calendar=ALL-UNNAMED

However, I think it should be possible to run the example without this workaround.

Any ideas what I'm missing? Might this even be a bug in Java/JDK 17?

Answer 1

It's reproducible with a plain Java application class as follows:

package com.stackoverflow.q72361100;

import java.lang.reflect.Method;
import java.util.TimeZone;

public class Test {
    public static void main(String... args) throws Exception {
        TimeZone instance = TimeZone.getDefault();
        Class<?> cls = instance.getClass();
        Method method = cls.getMethod("getRawOffset");
        Object result = method.invoke(instance); // java.lang.IllegalAccessException
        System.out.println(result);
    }
}

The issue here is that instance.getClass() returns sun.util.calendar.ZoneInfo as that's the implementation returned by TimeZone#getDefault(). The work around would be to use TimeZone.class instead of instance.getClass():

package com.stackoverflow.q72361100;

import java.lang.reflect.Method;
import java.util.TimeZone;

public class Test {
    public static void main(String... args) throws Exception {
        TimeZone instance = TimeZone.getDefault();
        Class<?> cls = TimeZone.class; // Work around
        Method method = cls.getMethod("getRawOffset");
        Object result = method.invoke(instance);
        System.out.println(result);
    }
}

I'd argue that this will require a change in EL spec. Ideally it should search further in declared super classes if the method is accessible as per Method#canAccess() and then use it instead.

package com.stackoverflow.q72361100;

import java.lang.reflect.Method;
import java.util.TimeZone;

public class Test {
    public static void main(String... args) throws Exception {
        TimeZone instance = TimeZone.getDefault();
        Class<?> cls = instance.getClass();
        Method method = getAccessibleMethod(instance, cls, "getRawOffset"); // Look in superclasses as well.
        Object result = method.invoke(instance);
        System.out.println(result);
    }

    private static Method getAccessibleMethod(Object instance, Class<?> cls, String methodName) throws NoSuchMethodException {
        Method method = cls.getMethod(methodName);

        if (method.canAccess(instance)) {
            return method;
        }

        return getAccessibleMethod(instance, cls.getSuperclass(), methodName);
    }

}

I've created an issue at EL spec: https://github.com/jakartaee/expression-language/issues/188

Until they get it fixed, you can work around it by adding a dedicated getter for it:

public int getDefaultTZrawOffset() {
    return getDefaultTZ().getRawOffset();
}

#{myWarBean.defaultTZrawOffset}