Referring to : http://jboss-javassist.github.io/javassist/tutorial/tutorial2.html
method.insertBefore("{ System.out.println($1);}");
This statement gives me following error:
Exception: javassist.CannotCompileException: [source error] no such field: $1
javassist.CannotCompileException: [source error] no such field: $1
at javassist.CtBehavior.insertBefore(CtBehavior.java:774)
at javassist.CtBehavior.insertBefore(CtBehavior.java:734)
at com.here.debugHelper.DurationTransformer.transform(DurationTransformer.java:124)
at sun.instrument.TransformerManager.transform(Unknown Source)
at sun.instrument.InstrumentationImpl.transform(Unknown Source)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at com.here.debugHelper.TestInstrumentation.main(TestInstrumentation.java:10)
Caused by: compile error: no such field: $1
at javassist.compiler.TypeChecker.fieldAccess(TypeChecker.java:845)
at javassist.compiler.TypeChecker.atFieldRead(TypeChecker.java:803)
at javassist.compiler.TypeChecker.atMember(TypeChecker.java:988)
at javassist.compiler.JvstTypeChecker.atMember(JvstTypeChecker.java:66)
at javassist.compiler.ast.Member.accept(Member.java:39)
at javassist.compiler.JvstTypeChecker.atMethodArgs(JvstTypeChecker.java:221)
at javassist.compiler.TypeChecker.atMethodCallCore(TypeChecker.java:735)
at javassist.compiler.TypeChecker.atCallExpr(TypeChecker.java:695)
at javassist.compiler.JvstTypeChecker.atCallExpr(JvstTypeChecker.java:157)
at javassist.compiler.ast.CallExpr.accept(CallExpr.java:46)
at javassist.compiler.CodeGen.doTypeCheck(CodeGen.java:242)
at javassist.compiler.CodeGen.atStmnt(CodeGen.java:330)
at javassist.compiler.ast.Stmnt.accept(Stmnt.java:50)
at javassist.compiler.CodeGen.atStmnt(CodeGen.java:351)
at javassist.compiler.ast.Stmnt.accept(Stmnt.java:50)
at javassist.compiler.Javac.compileStmnt(Javac.java:567)
at javassist.CtBehavior.insertBefore(CtBehavior.java:754)
... 17 more
Moreover,the same error appears when I use any parameter(passed to the parameter) or any local variable instead of '$1'. This has been covered in this question, but I don't really understand the solution there.
There is this other post with same question but no answer.
Please help. Thank you
Alright, this is how I worked around the problem. There were few mistakes that I was overlooking and some things that I learnt. I am sharing this since I could not find the content directly addressing the issue anywhere.
Referring to this answer and this article:
The insertBefore, insertAfter and other such methods cannot access any local variable but can access method parameter of the method by their names. no such field error occurs if attempt is made to access local variable.
These methods cannot access any parameter declared within them as a process of instrumentation.
ctmethod.insertBefore("{int i = 4; int j = 9;}")
ctmethod.insertBefore("i = 5;");
ctMethod.insertAfter("j = 9;");
The above code will give no such field: j(and i) error
insertBefore, insertAfter, expect a single statement, or a single block of code as done in first line of above code snippet.
This error no such field appears in case when variables are used in ctmethod.addcatch() too.
ctmethod.addLocalVariable() helps in declaring a variable that can be accessed by insertBefore(), etc. However, .addCatch() will still give no such field error if you try to use variable declared using .addLocalVariable()
I was getting no such field: $1 due to my silly mistake. I was going iterating through a number of method in a class, so the error was due to the fact that some of those methods had zero arguments. $1,$2.. and $args work well as explained in this doc.
P.S. I will add further tips as I come across them and any corrections are welcomed.
Related
I am trying to load an ontology saved on my PC. The file format is .n3.
After a lot of work and searching for the possible solutions, I didn't find an appropriate way to load an ontology.
I tried the following code:
import edu.stanford.smi.protegex.owl.ProtegeOWL;
import edu.stanford.smi.protegex.owl.model.OWLModel;
public class Extractor {
public static void main(String[] args) {
String ontologyURI = "file:///C:/acco.n3";
try {
OWLModel owlModel = ProtegeOWL.createJenaOWLModelFromURI(ontologyURI);
System.out.println("Worked");
}catch (Exception exception) {
System.out.println("Error can't upload the ontologie ");
}
}
}
but it always gives me this error:
Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/commons/logging/LogFactory
at com.hp.hpl.jena.graph.Node.<clinit>(Node.java:35)
at com.hp.hpl.jena.rdf.model.impl.ResourceImpl.fresh(ResourceImpl.java:108)
at com.hp.hpl.jena.rdf.model.impl.ResourceImpl.<init>(ResourceImpl.java:68)
at com.hp.hpl.jena.rdf.model.ResourceFactory$Impl.createResource(ResourceFactory.java:176)
at com.hp.hpl.jena.rdf.model.ResourceFactory.createResource(ResourceFactory.java:69)
at com.hp.hpl.jena.vocabulary.RDF.resource(RDF.java:29)
at com.hp.hpl.jena.vocabulary.RDF.<clinit>(RDF.java:37)
at com.hp.hpl.jena.datatypes.xsd.impl.XMLLiteralType.<clinit>(XMLLiteralType.java:30)
at com.hp.hpl.jena.datatypes.TypeMapper.<clinit>(TypeMapper.java:52)
at edu.stanford.smi.protegex.owl.model.impl.OWLSystemFrames.createRDFSDatatypes(Unknown Source)
at edu.stanford.smi.protegex.owl.model.impl.OWLSystemFrames.createOWLInstances(Unknown Source)
at edu.stanford.smi.protegex.owl.model.impl.OWLSystemFrames.createOWLMetaModel(Unknown Source)
at edu.stanford.smi.protegex.owl.model.impl.OWLSystemFrames.<init>(Unknown Source)
at edu.stanford.smi.protegex.owl.swrl.SWRLSystemFrames.<init>(Unknown Source)
at edu.stanford.smi.protegex.owl.model.impl.AbstractOWLModel.createSystemFrames(Unknown Source)
at edu.stanford.smi.protegex.owl.model.impl.AbstractOWLModel.createSystemFrames(Unknown Source)
at edu.stanford.smi.protege.model.DefaultKnowledgeBase.<init>(DefaultKnowledgeBase.java:79)
at edu.stanford.smi.protegex.owl.model.impl.AbstractOWLModel.<init>(Unknown Source)
at edu.stanford.smi.protegex.owl.jena.JenaOWLModel.<init>(Unknown Source)
at edu.stanford.smi.protegex.owl.jena.JenaKnowledgeBaseFactory.createKnowledgeBase(Unknown Source)
at edu.stanford.smi.protege.model.Project.createDomainKB(Project.java:429)
at edu.stanford.smi.protege.model.Project.createDomainKnowledgeBase(Project.java:447)
at edu.stanford.smi.protegex.owl.jena.creator.OwlProjectFromUriCreator.create(Unknown Source)
at edu.stanford.smi.protegex.owl.ProtegeOWL.createJenaOWLModelFromURI(Unknown Source)
at Extractor.main(Extractor.java:28)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:582)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:190)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:499)
... 25 more
I need your help in solving this error, or perhaps find a way to load ontologies to extract knowledge from them.
Thanks in advance.
Update:
I added the missing dependencies to the class path as #Roddy of the Frozen Peas suggested.
but it gives me the following error:
WARNING: [Local Folder Repository] The specified file must be a directory. (C:\eclipse-workspace\NewEx\plugins\edu.stanford.smi.protegex.owl) -- LocalFolderRepository.update()
Exception in thread "main" java.lang.NoClassDefFoundError: org/protege/editor/owl/model/hierarchy/roots/Relation
at edu.stanford.smi.protegex.owl.jena.parser.TripleProcessor.<init>(Unknown Source)
at edu.stanford.smi.protegex.owl.jena.parser.GlobalParserCache.getTripleProcessor(Unknown Source)
at edu.stanford.smi.protegex.owl.jena.parser.ProtegeOWLParser.loadTriples(Unknown Source)
at edu.stanford.smi.protegex.owl.jena.parser.ProtegeOWLParser.run(Unknown Source)
at edu.stanford.smi.protegex.owl.jena.JenaKnowledgeBaseFactory.loadKnowledgeBase(Unknown Source)
at edu.stanford.smi.protege.model.Project.loadDomainKB(Project.java:1346)
at edu.stanford.smi.protege.model.Project.createDomainKnowledgeBase(Project.java:456)
at edu.stanford.smi.protegex.owl.jena.creator.OwlProjectFromUriCreator.create(Unknown Source)
at edu.stanford.smi.protegex.owl.ProtegeOWL.createJenaOWLModelFromURI(Unknown Source)
at Extractor.main(Extractor.java:10)
Caused by: java.lang.ClassNotFoundException: org.protege.editor.owl.model.hierarchy.roots.Relation
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:582)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:190)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:499)
... 10 more
any suggestions please?
java.lang.ClassNotFoundException: org.protege.editor.owl.model.hierarchy.roots.Relation
There are other dependencies you need. Rather than going piecemeal, you should use a build system that can resolve the dependency closure for you, such as Maven, Gradle or similar.
The problem here is not Protege specific or ontology related, it's just plain Java libraries missing from the classpath.
Note that your code does not use OWL API. These classes are Jena classes and Protege classes (from Protege 3.x, I'd think). Note that Protege 3.x is a very dated API. Consider using a newer version (5.2.0 or newer), or directly using the actual OWL API. See https://github.com/owlcs/owlapi/wiki/Documentation
OWL API also has zip files containing all dependencies, which might simplify your work (Maven is still better than resolving dependencies by hand). See https://github.com/owlcs/releases/tree/master/owlapi/5
I started to get ClassFormatExceptions I couldn't explain relating to interfaces with static methods. I pruned it down to this test case:
public interface ModifierTest
{
public static final int DELTA = 10;
public static int increment(int value)
{
assert value > 0; // Problem line
return value + DELTA;
}
}
public class ModifierExec
{
public static void main(String[] args)
{
System.out.println(ModifierTest.class);
}
}
Without the assertion in the increment() method, everything is fine. But with the assertion, I get an exception at run time (compilation is fine):
Exception in thread "main" java.lang.ClassFormatError: Illegal field modifiers in class ModifierTest: 0x1018
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.defineClass(Unknown Source)
at java.net.URLClassLoader.access$100(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at com.c4.camgen.ModifierExec.main(ModifierExec.java:7)
This is easy to work round, but I'm curious as to whether this is a bug in Java or correct (if strange) behaviour. I can't find any references to assertions affecting field modifiers.
Can anyone tell me what's going on? Running in Eclipse Kepler, under jdk 1.8.0_20.
First of all, Eclipse has its own compiler so a possible bug is there, not in javac.
Now, Juno is an old version which predates Eclipse's support for Java 8 and earlier versions of Java did not allow static methods in the interface at all. This is where your report gets confusing.
Anyway, you should upgrade to Luna to work seamlessly with Java 8 in Eclipse.
I am using the Apertium Translator and using the sample code they provide. My code is like this.
import com.robtheis.aptr.language.Language;
import com.robtheis.aptr.translate.Translate;
public class Test {
public static void main(String[] args) throws Exception {
// Set the Apertium API Key - Get yours at http://api.apertium.org/register.jsp
Translate.setKey("BNSCFhEL8DoTApc2I1+aa3UYkVg");
String translatedText = Translate.execute("Hola, mundo!", Language.SPANISH, Language.ENGLISH);
System.out.println(translatedText);
}
}
I have no errors or warnings and when I run the program I get the following errors.
Exception in thread "main" java.lang.NoClassDefFoundError: org/json/simple/JSONValue
at com.robtheis.aptr.ApertiumTranslatorAPI.jsonSubObjToString(ApertiumTranslatorAPI.java:195)
at com.robtheis.aptr.ApertiumTranslatorAPI.retrieveSubObjString(ApertiumTranslatorAPI.java:140)
at com.robtheis.aptr.translate.Translate.execute(Translate.java:56)
at maple.Test.main(Test.java:11)
Caused by: java.lang.ClassNotFoundException: org.json.simple.JSONValue
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 4 more
The .jar I'm using is the second one from https://github.com/rmtheis/apertium-translator-java-api/downloads
You have to download the first one. The first jar file (apertium-translator-java-api-0.2-jar-with-dependencies.jar) contains the all dependencies needed..
Or you add a json library to your project path..
Well JVM is not able to find some class at Runtime which was available at compile time. That is the reason of NoClassDefFoundError
Below you also have ClassNotFoundException for this class org.json.simple.JSONValue
which means you are trying to load the particular class at run-time by name.
Both of them related to Java Class Path.
I don't know alot about jSON stuff. But you are missing this file org.json.simple.JSONValue you can take it from here http://code.google.com/p/json-simple/
add the above jar file in your class path . And the code will definitely run. Guaranteed.!!!
Thanks
I wanted to instrument some methods/classes in Java. For that purpose I wrote an Java agent that instruments only a few classes that I choose.
I use the following code to get the loaded classes and filter some of them:
instrumentation.addTransformer(myTransformer,true);
Class[] loadedClasses=instrumentation.getAllLoadedClasses();
Class[] modifiableClasses=ModifiableClasses(loadedClasses,instrumentation);
Class[] filteredClasses=filterClasses(modifiableClasses);
if(instrumentation.isRetransformClassesSupported()){
System.out.println("retransformation is Supported");
instrumentation.retransformClasses(filteredClasses);
}
this should not create any problem filterClasses returns some classes that I want to be instrumented normally I want to instrument these Classes:
Ljava/nio/Buffer;
Ljava/util/HashMap$Entry;
Ljava/nio/HeapCharBuffer;
Ljava/nio/CharBuffer;
Ljava/lang/ClassLoader;
Ljava/lang/Class;
Ljava/util/HashMap;
Ljava/nio/ByteBuffer;
Ljava/lang/System;
Ljava/io/BufferedWriter;
Ljava/lang/String;
Ljava/io/OutputStreamWriter;
Ljava/io/BufferedOutputStream;
Ljava/nio/charset/CoderResult;
Ljava/io/Writer;
Ljava/util/HashSet;
Ljava/nio/charset/CharsetEncoder;
Ljava/io/FileOutputStream;
Ljava/io/PrintStream;
everything works fine I print the instrumented and unistrumented classes in specific folders for debug. I use the asm CoreAPI to add some instructions at the beginning and the end of methods I dont instrument Constructors,native methods, abstract methods and static variables. When I just instrument the new classes that are being loaded everything works fine. I guess I dont understand something with the ClassLoader or something specific here is what I get on the Console:
Exception in thread "main" java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.instrument.InstrumentationImpl.loadClassAndStartAgent(Unknown Source)
at sun.instrument.InstrumentationImpl.loadClassAndCallPremain(Unknown Source)
Caused by: java.lang.InternalError
at sun.instrument.InstrumentationImpl.retransformClasses0(Native Method)
at sun.instrument.InstrumentationImpl.retransformClasses(Unknown Source)
at my.Agent.Watcher.premain(Watcher.java:88)
... 6 more
FATAL ERROR in native method: processing of -javaagent failed
I am thankful for any help I can get even a link or a hint in the right direction.
Sorry guys my mistake after looking more precisely in the instrumented classes I found Errors which I will have to solve, if I want this to work. An admin/mod can close this thread .
I want to write a classLoader that can help me implement customized classes and ultimately a whole component at run time. Right now I'm in process of loading the class.
I'm trying to load this role.java file. However when I get to this part of the code:
myClass = super.defineClass(className, classData, 0, classData.length);
I get this exception:
Exception in thread "main" java.lang.ClassFormatError: Incompatible magic value 1885430635 in class file C:\Users\ARIFAH\Downloads\Compressed\eUML2 free version\with classLoader code\2\archetypedComponentWithNull\src\aC\Role/java
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(Unknown Source)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.lang.ClassLoader.defineClass(Unknown Source)
at customCL.customClassLoader.loadClass(customClassLoader.java:116)
at java.lang.ClassLoader.loadClass(Unknown Source)
at customCL.customClassLoader.main(customClassLoader.java:145)
I've read posts saying "you need something like OSGi". That would be similar to working on something new from scratch, which I'd like to avoid.
Why am I getting this error?
You aren't actually loading a real class file. The magic value of any valid class file is 0xCAFEBABE, and this magic in hex is 0x7061636B.
Notice that if we convert 0x7061636B to ASCII byte by byte, it turns out to be the string "pack". This means that the file you think is a class file actually starts with the string "pack".