java-bytecode-asm

I am trying to manipulate a static method. For this, Byte Buddy or any other framework can be used. There is one library that is called Pi4J that is used for controlling GPIO of Raspberry Pi. This library has a method called: GpioController gpio = GpioFactory.getInstance(); And this call is called in several places of a program that I might not have control such that I need to modify the invocation. What I would like to do is that when GpioFactory.getInstance is executed in some way detect and modify the methods of GpioController so they log that they have been called. Maybe the only solution

I am using ASM 5.0.3 bytecode modification library with Tomcat 8 and JDK 8. My intention is to inject bytecode successfully into all the classes. However, I encountered the following error: java.lang.VerifyError: Expecting a stackmap frame at branch target 18 Exception Details: Location: com/sun/crypto/provider/SunJCE.getInstance()Lcom/sun/crypto/provider/SunJCE; @0: getstatic Reason: Expected stackmap frame at this location. Bytecode: 0x0000000: b200 0bc7 000b bb00 3659 b700 0cb0 b200 0x0000010: 0bb0 bf Exception Handler Table: bci [0, 18] => handler: 18 Stackmap Table: append_frame(@14

Using a library like ASM or cglib , is there a way to add bytecode instructions to a class to execute code whenever the value of a class field is set? For example, let’s say I have this class: public class Person { bool dirty; public String name; public Date birthDate; public double salary; } Let’s say a section of code contains this line: person.name = "Joe"; I want this instruction to be intercepted so the dirty flag is set to true . I know this is possible for setter methods -- person.setName (“Joe”) -- as class methods can be modified by bytecode manipulation, but I want to do the same

I am trying to figure out the bytecode size of a method because I want to be sure that it will be small enough to be inlined by compiler optimizations. I saw that the default max size for inlining methods is 35, so if the method is larger than that I will revise the code or break it into multiple methods. I have a method that generates the bytecode below (disassembled via the ASM Bytecode Outline plugin for IntelliJ IDEA). How can I tell the bytecode size of that method? the LINENUMBERs seem to reference the line numbers of the original source code. TIA public static mergeNativeArrays([Ljava

I am writing a static analysis tool for an assignment, it analyses Java bytecode using the ASM library. One of the parts of ASM that we use requires (or at least, appears to require) that the class be loaded from the ClassLoader. We were hoping the tool would be able to analyse .class files without requiring them on the classpath. We already load the .classes from a specified directory at run time and read them in using an InputStream. This is acceptable for ASM in most cases. There are some classes, such as SimpleVerifier , which attempt to load the classes though. Is it possible, under this