Hi, Is there any way of caching the bytecode for JSP webapps/ In particular, using Tomcat as the Java servlet? I'm getting really fed up of Tomcat taking up all the CPU for 10 minutes while it compiles 4 different webapps every time I restart it.... I'm already using Jikes to "speed up" the compiles, but it's really killing me. The cod...
I am currently instrumenting bytecode using BCEL. In the BCEL API, the two instructions types LOOKUPSWITCH and TABLESWITCH (package org.apache.bcel.generic) are implementing interface StackProducer. I know that these two instructions pop the operand stack (i.e. consume it) and do not produce anything on the stack, so how come they implem...
What's a good free bytecode editor? I want an editor, something with a GUI... I tried jbe-0.1b with no luck (can't save the bytecode changes). ...
App Engine uses a "precompilation" process with the Java bytecode of an app to enhance the performance of the app in the Java runtime environment. Precompiled code functions identically to the original bytecode. Is there any detailed information what this does? ...
Examining bytecode, I've noticed javac seems to duplicate checkcast instructions when casting to array types. Cast.java: class Cast { void test(Object a) { Object[] b = (Object[])b; } } javap disassembly of the javac compiled version void test(java.lang.Object); Code: 0: aload_1 1: checkcast #2; //class "[Ljava/...
Which useful (for performance or otherwise) constructions are valid bytecode, but not expressable in Java? ...
I used Java for like 6-7 years, then some months ago I discovered Groovy and started to save a lot of typing.. then I wondered how certain things worked under the hood (because groovy performance is really poor) and understood that to give you dynamic typing every Groovy object is a MetaClass object that handles all the things that the J...
I have played around with Scala for a while now, and I know that traits can act as the Scala equivalent of both interfaces and abstract classes. Recently I've been wondering how exactly traits are compiled into Java bytecode. I found some short explanations that stated traits are compiled exactly like Java interfaces when possible, and...
As the title indicates, are there any C/C++ bytecode compilers/interpreters? I'm writing an application in an interpreted language that depends on certain libraries that are fully cross-compilable (there are no special flags to indicate code changes during compilation for a certain platform) but are written in C and C++. Rather than ship...
It looks like I'm missing something. When using Jython to run my Python code in Java, Java bytecode files are generated (test.py -> [email protected]). Can I run these classes directly using java? In other words, I want to make this: $ java test@py [additional cp args] work. The intent: writing Python code and not having to give away ...
I work for a company that created firmware for several device using FreeRTOS. Lately our request for new features has surpassed how much work our firmware engineers are capable of, but we can't afford to hire anyone new right now either. Making even tiny changes requires firmware people to go in and modify things at a very low level. ...
My point is, if you don't understand the abstraction of a framework, you can still decompile it and understand it, because you know the language e.g. Java. However, when byte-code generation happens, you have to understand even a lower level - JVM level byte-codes. I am really affraid of using any of such frameworks, which are many. Most...
class A { void F() { System.out.println("a"); }} class B extends A { void F() { System.out.println("b"); }} public class X { public static void main(String[] args) { A objA = new B(); objA.F(); } } Here, F() is being invoked dynamically, isn't it? This article says: ... the Java bytecode doesn’t ...
If I have an abc file, either compiled through the flex SDK, or stripped from a .SWF file, are there any tools that will disassemble that file purely to see what it contains? ...
Hi. I'd like to have access to the bytecode that is currently running or about to run in order to detect certain instructions and take specific actions (depending the instructions). In short, I'd like to monitor the bytecode in order to add safety control (see EDIT #1 for explanation). Is this possible? I know there are some AOP framew...
Hey everyone, I've been working for some time on (Java) Bytecode, however, it had never occurred to me to ask why are some instructions typed? I understand that in an ADD operation, we need to distinguish between an integer addition and a FP addition (that's why we have IADD and FADD). However, why do we need to distinguish between ISTO...
So i am trying to write a program that can read in a java class file as bytecode. For this i am using Data.Binary and Data.ByteStream. The problem i am having is because im pretty new to Haskell i am having trouble actually using these tools. module Main where import Data.Binary.Get import Data.Word import qualified Data.ByteString.Lazy...
Is there anything the Dalvik VM supports (in terms of bytecode) which is not used currently because the .class files don't have it? As an example, if people would write their own Source-to-DX converter for their functional language XYZ, would they be able to implement e. g. full tail calls although the .class file does support tail call...
What legitimate uses are there for bytecode manipulation and how people implement those bytecode manipulation based solutions in practice? Update: I should have made it more clear that this question really is about what patterns and techniques people use to make their code fly with the help of bytecode manipulation. Something like aspe...
In Java, is there a way (at runtime) to obtain the bytecode which defined a particular class? Put another way, is there a way to obtain the byte[] array passed to ClassLoader.defineClass(String name, byte[] b, int off, int len) when a particular class was loaded? I see that this method is declared final, so creating a custom ClassLoader...