fix jad commnad VerifyError when the class is created by lambda expression. #675

core/src/main/java/com/taobao/arthas/core/command/klass100/JadCommand.java

@@ -26,8 +26,12 @@ import com.taobao.text.ui.LabelElement;
 import com.taobao.text.ui.TableElement;
 import com.taobao.text.util.RenderUtil;
 
+import static java.lang.System.arraycopy;
+
 import java.io.File;
+import java.lang.instrument.ClassFileTransformer;
 import java.lang.instrument.Instrumentation;
+import java.lang.instrument.UnmodifiableClassException;
 import java.util.*;
 import java.util.regex.Pattern;
 
@@ -118,6 +122,27 @@ public class JadCommand extends AnnotatedCommand {
         }
     }
 
+
+    public static void retransformClasses(Instrumentation inst, ClassFileTransformer transformer, Set<Class<?>> classes) {
+        try {
+            inst.addTransformer(transformer, true);
+
+            for(Class<?> clazz : classes) {
+                try{
+                    inst.retransformClasses(clazz);
+                }catch(Throwable e) {
+                    String errorMsg = "retransformClasses class error, name: " + clazz.getName();
+                    if(ClassUtils.isLambdaClass(clazz) && e instanceof VerifyError) {
+                        errorMsg += ", Please ignore lambda class VerifyError: https://github.com/alibaba/arthas/issues/675";
+                    }
+                    logger.error("jad", errorMsg, e);
+                }
+            }
+        } finally {
+            inst.removeTransformer(transformer);
+        }
+    }
+
     private void processExactMatch(CommandProcess process, RowAffect affect, Instrumentation inst, Set<Class<?>> matchedClasses, Set<Class<?>> withInnerClasses) {
         Class<?> c = matchedClasses.iterator().next();
         Set<Class<?>> allClasses = new HashSet<Class<?>>(withInnerClasses);
@@ -125,7 +150,8 @@ public class JadCommand extends AnnotatedCommand {
 
         try {
             ClassDumpTransformer transformer = new ClassDumpTransformer(allClasses);
-            Enhancer.enhance(inst, transformer, allClasses);
+            retransformClasses(inst, transformer, allClasses);
+
             Map<Class<?>, File> classFiles = transformer.getDumpResult();
             File classFile = classFiles.get(c);
 

core/src/main/java/com/taobao/arthas/core/util/ClassUtils.java

@@ -23,6 +23,10 @@ public class ClassUtils {
         return cs.getLocation().getFile();
     }
 
+    public static boolean isLambdaClass(Class<?> clazz) {
+        return clazz.getName().contains("$$Lambda$");
+    }
+
     public static Element renderClassInfo(Class<?> clazz) {
         return renderClassInfo(clazz, false, null);
     }