Stack Overflow
Stack Overflow

Questions tagged [byte-buddy]

Byte Buddy is a code generation and manipulation library for creating and modifying Java classes during the runtime of a Java application and without the help of a compiler. Byte Buddy allows the creation of arbitrary classes and is not limited to implementing interfaces for the creation of runtime proxies. Furthermore, Byte Buddy offers a convenient API for changing classes either manually, using a Java agent or during a build.

Byte Buddy is a code generation and manipulation library for creating and modifiying Java classes during the runtime of a Java application and without the help of a compiler. Other than the code generation utilities that ship with the Java Class Library, Byte Buddy allows the creation of arbitrary classes and is not limited to implementing interfaces for the creation of runtime proxies. Furthermore, Byte Buddy offers a convenient API for changing classes either manually, using a Java agent or during a build.

In order to use Byte Buddy, one does not require an understanding of Java byte code or the class file format. In contrast, Byte Buddy's API aims for code that is concise and easy to understand for everybody. Nevertheless, Byte Buddy remains fully customizable down to the possibility of defining custom byte code. Furthermore, the API was designed to be as non-intrusive as possible and as a result, Byte Buddy does not leave any trace in the classes that were created by it. For this reason, the generated classes can exist without requiring Byte Buddy on the class path. Because of this feature, Byte Buddy's mascot was chosen to be a ghost.

Byte Buddy is written in Java 6 but supports the generation of classes for any Java version. Byte Buddy is a light-weight library and only depends on the visitor API of the Java byte code parser library ASM which does itself not require any further dependencies.

749 questions
0
votes
1 answer

Alter method access to an argument using bytebuddy

I have a case like the example below public String test(Trail trail) { AnotherClass.access(trail); this.executeAnotherMethod(trail); futureCall(trail::end); return "emptyString"; } And I want to use byte-buddy to do something like…
duke
  • 1
0
votes
1 answer

byte-buddy (byte code manipulation) interceptor dont work: None of

I have to add annotation XmlElementWrapper and XmlElement to field of list type, but these annotation required name. I would to set property name to field name. I do: new ByteBuddy() .redefine(className) …
robyp7
  • 481
  • 2
  • 7
  • 25
0
votes
1 answer

DriverManager with Mockito

I am trying to migrate a library to java 10 but I have some errors regarding Mockito and Byte Buddy. Here is the piece of registration logic of java.sql.Driver underlayingDriver = mock(java.sql.Driver.class); underlayingDriver =…
Cemo
  • 5,370
  • 10
  • 50
  • 82
0
votes
1 answer

Append Agent to classpath

I am trying to instrument Java ThreadPoolExecutor class using byte buddy. I am using my own logger to get logs from agent. But when i try to use this logger with Advice its gives following error. Exception in thread "main"…
Shehan Perera
  • 339
  • 1
  • 18
0
votes
1 answer

Add a method to a class using byte-buddy

I am trying to add a method to a class using Java agent.But its gives a error as follows. java.lang.VerifyError: Local variable table overflow Exception Details: Location:com/github/shehanperera/example/Method.method1()V @3: aload_0 Reason:…
Shehan Perera
  • 339
  • 1
  • 18
0
votes
1 answer

Slf4j loggers with Byte Buddy

I try to instrument a java class called ThreadPoolExecutor and i want to get details of threads using slf4j loggers and I am getting following error Exception in thread "pool-2-thread-2" Exception in thread "pool-2-thread-1"…
Shehan Perera
  • 339
  • 1
  • 18
0
votes
1 answer

[byte-buddy]Why only last interceptor works

There is a method testFooin my code which looks like this: newClassBuilder = newClassBuilder.method(ElementMatchers.nameStartsWith("test")) .intercept(MethodDelegation.to(new InstMethodsInter(new…
hao117
  • 3
  • 3
0
votes
1 answer

ByteBuddy - create Interface of getter/setter's

I am trying to generate an Intgerface from a List, where the elements represent 'get' methods. The Interface is generated without Exception, but when I reflectively try to get the methods of the Interface of the Dynamic type, there are no Methods…
k m
  • 11
  • 3
0
votes
1 answer

Bytebuddy javaagent intercepting spring beans annotated with *.Controller

As the title suggests, I'm making a javaagent where the main purpose is to make a nice logger for any spring boot application; for now. What I do at the moment is typically: private static void install(String className, String methoName,…
Solve Johnsen
  • 67
  • 1
  • 1
  • 7
0
votes
1 answer

Attach an agent remotely using Bytebuddy

I am trying to attach an agent for a process using bytebuddy .I found that we can use ByteBuddyAgent.attach(file,"18467"); for this. But when i am trying to do this following errors occurring. This is agent i used File file = (new…
Shehan Perera
  • 339
  • 1
  • 18
0
votes
1 answer

Proxy for a class with no empty constructor using ByteBuddy

Is there a way to create a proxy for a class with no empty constructor using ByteBuddy? The idea is to create a proxy for a given concrete type and then redirect all the methods to a handler. This test showcases the scenario of creation of a proxy…
diegomtassis
  • 3,557
  • 2
  • 19
  • 29
0
votes
1 answer

Transform only one class quickly using a Java Agent

I want to measure the startup time of a server without a considerable overhead. What I actually want to measure is the time from server process execution to the time that the server starts listening to a well-known port. For example, I want to…
Isuru Perera
  • 1,905
  • 1
  • 11
  • 23
0
votes
1 answer

Adding field to class causes " does not define an index 2" exception

I am trying to add a field to sub classes of type java.sql.Connection in an effort to monitor connections that are open for an extended period of time (e.g. connection leak). This is what I am trying to run with: public class…
SnowArk
  • 41
  • 3
0
votes
1 answer

When attaching agent to running process, bytebuddy transformer doesn't seem to take effect

The code of my program to be attached is as below. public class Foo { } public class TestEntry { public TestEntry() { } public static void main(String[] args) throws Exception { try { while(true) { …
surlary
  • 1
  • 1
0
votes
0 answers

reference to object created by the transformer

class Foo{ private final Object obj0; private final Object obj1; private final Object def; Public Foo(obj0,obj1,def){ this.obj0 = obj0; this.obj1 = obj1; this.def = def; } public int foo(long v){ …
User1291
  • 7,664
  • 8
  • 51
  • 108
1 2 3
…
49 50