java-bytecode-asm

问题 I am developing a small Spring application. I have to store the details of the student information in the database. I have developed one SimpleFormController. I have used NetBeans + Hibernate mapping + Spring. When I deploy the project, the following errors occurs. My spring-config-db-applicationContext.xml is shown below: <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd"> <beans> <!-- Hibernate

问题 I'm having a hard time seeing how LocalVariablesSorter from ASM is able to keep variable slot collisions from happening. A variable might come from the original source, or I might create a variable with LocalVariablesSorter.newLocal(Type t). Later on, visitVarInsn aise going to come in for those slots. Both from the original code, and from my injected code. How could LocalVariablesSorter tell them apart. They will both have the same slot index, how does it move one to the proper slot? I don't

问题 Using ASM Bytecode Can we identify for loops or while loops present in the method body? 回答1: It depends on which information you want to extract. In principle, you can detect loops by searching for backward branches . A loop can’t work without and with usual code structures you won’t find backward branches which are not part of a loop. So if you want to have them named explicitly, all of the bytecode instructions goto , goto_w , if_acmpeq , if_acmpne , if_icmpeq , if_icmpge , if_icmpgt , if

问题 I am building a dependency search tool using ASM 4.0 and I have found a corner case which I have been unable to solve. The problem I'm having has to do with identifing usages of MyClass in the code below. public void aMethod() { new ArrayList<? extends MyClass>(); } The usage of ArrayList can be identified using MethodVisitor.visitTypeInst(), but no signature method is available in that scope to identify the usage in the generic type parameter. MethodVisitor.visitLocalVariable() is not the

问题 While instrumenting a class for its different methods In order to make a method do a write operation in a text file. I first stored the string in a local variable 3160 explicitly defined. How to choose these variables to prevent conflicts with already existing variables. Like in this snippet The code does the work of writing the class name to a text file every time it enters any method. In order to do so the string s had to be loaded on stack using variable 3160 ( value kept large so that the

问题 This is the code im using String fieldName = "lock"; String fieldType = "Ljava/util/concurrent/locks/Lock;"; Object initValue = new ReentrantLock(); cw.visitField(ACC_PUBLIC, fieldName, fieldType, null, initValue).visitEnd(); Im attempting to add a line of "Lock lock = new ReentrantLock();" but asm is throwing a error Exception in thread "main" java.lang.IllegalArgumentException: value class java.util.concurrent.locks.ReentrantLock at org.objectweb.asm.ClassWriter.a(Unknown Source) 回答1: You

问题 I can't get Intellij Idea 13.0 to compile my code against ASM 5.0.3 I have a multi-module Maven project. It compiles and installs successfully. Apparently com.google.findbugs:findbugs has a dependency on asm:asm:3.3 and I want to use org.ow2.asm:asm:5.0.3 to manipulate some bytecode. So in the parent pom.xml I exclude the asm:asm:3.3 dependencies from the classpath. This works fine when I run mvn install from the command line. I can't get the Build -> Make Project menu selection to work in

问题 I want to visit classes that are passed in a method I tried visitMethodInsn in my MethodVisitor but I get the method signature, not the class passed when it’s executed public static class C { } public static class B { void myMethod(Class clz) { } } public static class A { static B getB() { return new B(); } } public static class Foo { public Foo() { A.getB().myMethod(C.class); } } So based on the code above, when visiting the Foo class I want to be noticed that C.class is being passed to

问题 So I have a class Foo that should eventually adjust and reload classes. It has a method for that, too: private void redefineClass(String classname, byte[] bytecode) { ClassFileLocator cfl = ClassFileLocator.Simple.of(classname,bytecode); Class clazz; try{ clazz = Class.forName(classname); }catch(ClassNotFoundException e){ throw new RuntimeException(e); } Debug._print("REDEFINING %s",clazz.getName()); new ByteBuddy() .redefine(clazz,cfl) .make() .load(clazz.getClassLoader(),

问题 How can I inspect the bytecode of a class (using something such as ASM) to learn which initial values were passed through to a method? For example: Given some methods that pass values to each other: void m1(Object o) { Object v = o; m2(v); m2("box"); } void m2(Object o) { Object v = o; m3(x); } void m3(Object o) { } And some method calls, all defined in the same class: { Object foo = "foo"; m1(foo); m2("bar"); m3("baz"); } How can I inspect the class' bytecode to learn that m3 will be called