javaagents

问题 Is there a (pref portable) way to check if The JVM has been stated with a particular -javaagent ? In particular I'm interested to know if the aspectj load time weaver has loaded or not. (I'm trying to provide a helpful error msg in the case of incorrect startup). 回答1: The following code shows a way to determine any -javaagent:... JVM arguments, a way to check if the AspectJ weaving agent entry point class (the one mentioned in the manifest entry Premain-Class: of aspectjweaver.jar ) is loaded

问题 I understand Spring avoids using the -javaagent vm option in order to get its AspectJ load time weaving to work and relies instead on a classloader to start the agent. I thought that the Java specification dictated that the only way to use a Java agent was through the -javaagent vm option. Am I wrong? Can someone please direct me to the official Java specification/documentation that would clarify my interrogation? 回答1: I found some information about loading java agents in this interesting

问题 I'm aware of how to start a java progam with a java agent: java -javaagent:myAgent.jar MyJavaProgram But what if I want to add 2 or more java agents to instrument my program? I do not want to reinvoke the java -javaagent:... for every agent I have to load in JVM. I've tried something like this : java -javaagent:agentA.jar, agentB.jar MyJavaProgram or something like this: java -javaagent:agentA.jar agentB.jar MyJavaProgram But have no success. Is there an answer to solve my problem ? Thank you

问题 I'm aware of how to start a java progam with a java agent: java -javaagent:myAgent.jar MyJavaProgram But what if I want to add 2 or more java agents to instrument my program? I do not want to reinvoke the java -javaagent:... for every agent I have to load in JVM. I've tried something like this : java -javaagent:agentA.jar, agentB.jar MyJavaProgram or something like this: java -javaagent:agentA.jar agentB.jar MyJavaProgram But have no success. Is there an answer to solve my problem ? Thank you

问题 I started learning Java Agent few days ago. But documentation is not very good and beginners like me struggling to understand the basics. I created a basic multiplier class and export it to runnable jar using eclipse. Here is the code snippet. Main jar file: public class Multiplier { public static void main(String[] args) { int x = 10; int y = 25; int z = x * y; System.out.println("Multiply of x*y = " + z); } } Bytecode for above class Now I want to manipulate the value of x from an agent. I

问题 I want to print out all methods that get called during runtime. They should be printed out in the order that they're called in and if they're called multiple times, they should be printed multiple times. This can be used for reverse engineering - seeing which functions get called when you press a button or do a specific action. I want to use Java agents and instrumentation for this. 回答1: This can be done using Java Agents and an instrumentation library. Java agent - Separate code that can be

问题 Long story short: I need to transform every class in my program (even the java library that are loaded before my agent). I have find a way to do it but is not completly working. I'm open to new ideas. My actual method act strange: it's supposed to print the same names in file and console but they are not. I'm sure that those classes reach my transform method because if I try to instrument them I get an error. Complete story: I have created an agent in order to inject some custom code in every

问题 I'm using a Java Agent and Javassist to add some logging to some JDK classes. Essentially when the system loads some TLS classes, Javassist will add some additional bytecode to them to help me debug some connection problems. Here's the problem, given this class is included in the agent jar: package com.something.myagent; public class MyAgentPrinter { public static final void sayHello() { System.out.println("Hello!"); } } In my agent's transform method, let's say I tried to invoke that class

问题 When trying to deploy my web application on Tomcat 6 I have this error. It is caused by a SSO pass-through filter in my application. My SiteMinder version is 6.0.5.35. java.lang.UnsatisfiedLinkError: netegrity.siteminder.javaagent.AgentAPI.javaagent_api_init(Lnetegrity/siteminder/javaagent/InitDef;)I at netegrity.siteminder.javaagent.AgentAPI.javaagent_api_init(Native Method) at netegrity.siteminder.javaagent.AgentAPI.init(AgentAPI.java:509) at org.jod.realm.provider.smautenticator

问题 The problem to fix I have a java agent in a database on a Lotus Domino 8.5.3 server, to create export data on a network drive. The signer of the agent is listed in all of the programmability restrictions fields of the server document. The windows user name of the server is added the folder with all access, except "Full access" and "Special rights". The agent can not create the file on the network drive, but can create the file on the local drive. The error message (Domino server log) 2013.01