8016644: Improve UnsupportedClassVersionError message

Improved the UnsupportedClassVersionError message to hopefully be more user friendly

Reviewed-by: coleenp, dholmes, twisti

hotspot/src/share/vm/classfile/classFileParser.cpp

@@ -3746,18 +3746,24 @@ instanceKlassHandle ClassFileParser::parseClassFile(Symbol* name,
       Exceptions::fthrow(
         THREAD_AND_LOCATION,
         vmSymbols::java_lang_UnsupportedClassVersionError(),
-        "Unsupported major.minor version %u.%u",
+        "Unsupported class file version %u.%u, "
+        "this version of the Java Runtime only recognizes class file versions up to %u.%u",
         major_version,
-        minor_version);
+        minor_version,
+        JAVA_MAX_SUPPORTED_VERSION,
+        JAVA_MAX_SUPPORTED_MINOR_VERSION);
     } else {
       ResourceMark rm(THREAD);
       Exceptions::fthrow(
         THREAD_AND_LOCATION,
         vmSymbols::java_lang_UnsupportedClassVersionError(),
-        "%s : Unsupported major.minor version %u.%u",
+        "%s has been compiled by a more recent version of the Java Runtime (class file version %u.%u), "
+        "this version of the Java Runtime only recognizes class file versions up to %u.%u",
         name->as_C_string(),
         major_version,
-        minor_version);
+        minor_version,
+        JAVA_MAX_SUPPORTED_VERSION,
+        JAVA_MAX_SUPPORTED_MINOR_VERSION);
     }
     return nullHandle;
   }

hotspot/test/runtime/ClassFile/UnsupportedClassFileVersion.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @library /testlibrary
+ * @compile -XDignore.symbol.file UnsupportedClassFileVersion.java
+ * @run main UnsupportedClassFileVersion
+ */
+
+import java.io.File;
+import java.io.FileOutputStream;
+import jdk.internal.org.objectweb.asm.ClassWriter;
+import jdk.internal.org.objectweb.asm.MethodVisitor;
+import jdk.internal.org.objectweb.asm.Opcodes;
+import com.oracle.java.testlibrary.*;
+
+public class UnsupportedClassFileVersion implements Opcodes {
+    public static void main(String... args) throws Exception {
+        writeClassFile();
+        ProcessBuilder pb = ProcessTools.createJavaProcessBuilder(true, "-cp", ".",  "ClassFile");
+        OutputAnalyzer output = new OutputAnalyzer(pb.start());
+        output.shouldContain("ClassFile has been compiled by a more recent version of the " +
+                            "Java Runtime (class file version 99.0), this version of " +
+                            "the Java Runtime only recognizes class file versions up to " +
+                            System.getProperty("java.class.version"));
+
+        output.shouldHaveExitValue(1);
+    }
+
+    public static void writeClassFile() throws Exception {
+        ClassWriter cw = new ClassWriter(0);
+        MethodVisitor mv;
+
+        cw.visit(99, ACC_PUBLIC + ACC_SUPER, "ClassFile", null, "java/lang/Object", null);
+        mv = cw.visitMethod(ACC_PUBLIC, "<init>", "()V", null, null);
+        mv.visitCode();
+        mv.visitVarInsn(ALOAD, 0);
+        mv.visitMethodInsn(INVOKESPECIAL, "java/lang/Object", "<init>", "()V", false);
+        mv.visitInsn(RETURN);
+        mv.visitMaxs(1, 1);
+        mv.visitEnd();
+        cw.visitEnd();
+
+        try (FileOutputStream fos = new FileOutputStream(new File("ClassFile.class"))) {
+             fos.write(cw.toByteArray());
+        }
+    }
+}

hotspot/test/testlibrary/com/oracle/java/testlibrary/ProcessTools.java

@@ -142,11 +142,23 @@ public final class ProcessTools {
    * with any platform specific arguments prepended
    */
   public static ProcessBuilder createJavaProcessBuilder(String... command) throws Exception {
+    return createJavaProcessBuilder(false, command);
+  }
+
+  public static ProcessBuilder createJavaProcessBuilder(boolean addTestVmOptions, String... command) throws Exception {
     String javapath = JDKToolFinder.getJDKTool("java");
 
     ArrayList<String> args = new ArrayList<>();
     args.add(javapath);
     Collections.addAll(args, getPlatformSpecificVMArgs());
+
+    if (addTestVmOptions) {
+      String vmopts = System.getProperty("test.vm.opts");
+      if (vmopts != null) {
+        Collections.addAll(args, vmopts.split("\\s"));
+      }
+    }
+
     Collections.addAll(args, command);
 
     // Reporting
@@ -157,5 +169,4 @@ public final class ProcessTools {
 
     return new ProcessBuilder(args.toArray(new String[args.size()]));
   }
-
 }