Merge pull request #218 from jamezp/LOGMGR-218

[LOGMGR-218] An MR JAR is not supported for the boot class path. Chec…

core/src/main/java/org/jboss/logmanager/JDKSpecific.java

@@ -25,6 +25,8 @@
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Set;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 import org.jboss.modules.Module;
 import org.jboss.modules.Version;
@@ -37,6 +39,7 @@ private JDKSpecific() {}
 
     private static final Gateway GATEWAY;
     private static final boolean JBOSS_MODULES;
+    private static final boolean MODULAR_JVM;
 
     static {
         GATEWAY = AccessController.doPrivileged(new PrivilegedAction<Gateway>() {
@@ -50,6 +53,23 @@ public Gateway run() {
             jbossModules = true;
         } catch (Throwable ignored) {}
         JBOSS_MODULES = jbossModules;
+
+        // Get the current Java version and determine, by JVM version level, if this is a modular JDK
+        final String value = AccessController.doPrivileged(new PrivilegedAction<String>() {
+            @Override
+            public String run() {
+                return System.getProperty("java.specification.version");
+            }
+        });
+        // Shouldn't happen, but we'll assume we're not a modular environment
+        boolean modularJvm = false;
+        if (value != null) {
+            final Matcher matcher = Pattern.compile("^(?:1\\.)?(\\d+)$").matcher(value);
+            if (matcher.find()) {
+                modularJvm = Integer.parseInt(matcher.group(1)) >= 9;
+            }
+        }
+        MODULAR_JVM = modularJvm;
     }
 
     static final class Gateway extends SecurityManager {
@@ -58,6 +78,17 @@ protected Class<?>[] getClassContext() {
         }
     }
 
+    /**
+     * Determines whether or not this is a modular JVM. The version of the {@code java.specification.version} is checked
+     * to determine if the version is greater than or equal to 9. This is required to disable specific features/hacks
+     * for older JVM's when the log manager is loaded on the boot class path which doesn't support multi-release JAR's.
+     *
+     * @return {@code true} if determined to be a modular JVM, otherwise {@code false}
+     */
+    static boolean isModularJvm() {
+        return MODULAR_JVM;
+    }
+
     static Class<?> findCallingClass(Set<ClassLoader> rejectClassLoaders) {
         for (Class<?> caller : GATEWAY.getClassContext()) {
             final ClassLoader classLoader = caller.getClassLoader();

core/src/main/java/org/jboss/logmanager/LogLevelInitTask.java

@@ -39,6 +39,11 @@ class LogLevelInitTask implements PrivilegedAction<Void> {
 
     @SuppressWarnings({ "unchecked" })
     public Void run() {
+        // If this is a modular JVM ignore the level hack. The check here is required when the log manager is added to
+        // the boot class path. The boot class path does not support multi-release JAR's.
+        if (JDKSpecific.isModularJvm()) {
+            return null;
+        }
         /* This mysterious-looking hack is designed to trick JDK logging into not leaking classloaders and
            so forth when adding levels, by simply shutting down the craptastic level name "registry" that it keeps.
         */

core/src/main/java9/org/jboss/logmanager/JDKSpecific.java

@@ -55,6 +55,15 @@ private JDKSpecific() {}
         JBOSS_MODULES = jbossModules;
     }
 
+    /**
+     * Always returns {@code true}.
+     *
+     * @return {@code true}
+     */
+    static boolean isModularJvm() {
+        return true;
+    }
+
     static Class<?> findCallingClass(Set<ClassLoader> rejectClassLoaders) {
         final SecurityManager sm = System.getSecurityManager();
         if (sm != null) {