javaagent-bytebuddy

This include several agents created using Byte-Buddy. Using this project we can get an idea how to create effective agents with byte-buddy.

How to use

1. Download iavaagent-bytebuddy project

git clone https://github.com/ShehanPerera/javaagent-bytebuddy.git

2. Install the project

mvn clean package

3.Run example java progaram

• Go to the directory

javaagent-bytebuddy/samples/example-run/target

• Run project

java -jar example-run-1.0-SNAPSHOT.jar

Please read My blog ‘@shehanperera.office/java-agents-with-byte-buddy-93185305c9e9">Java Agents with Byte-Buddy‘ to get an idea how the codes working.

Use agents with Byte-Buddy

1. Get all methods running in program

• Copy get-methods-1.0-SNAPSHOT.jar form javaagent-bytebuddy/samples/get-methods/target to
  javaagent-bytebuddy/samples/example-run/target

• Run example with agent

  java -javaagent:get-methods-1.0-SNAPSHOT.jar -jar example-run-1.0-SNAPSHOT.jar

  • Results

``` Agent for get all methods
This is Sample main
This is constructor
This is Method 1
public void com.github.shehanperera.example.Method.method1()
This is Method 2
public void com.github.shehanperera.example.Method.method2()
String :parameters and number :4 and boolean :true
public void com.github.shehanperera.example.Method.method4(int,java.lang.String,boolean)
public static void com.github.shehanperera.example.Sample.main(java.lang.String[])

<b>2. Get execution time of all methods </b>
* Copy `execution-time-1.0-SNAPSHOT.jar` form `javaagent-bytebuddy/samples/execution-time/target` to 
`javaagent-bytebuddy/samples/example-run/target`
* Run example with agent 
 `java -javaagent:execution-time-1.0-SNAPSHOT.jar -jar example-run-1.0-SNAPSHOT.jar`
 * Results 
  ``` Agent for time measure
      This is Sample main
      This is constructor 
      This is Method 1
      public void com.github.shehanperera.example.Method.method1() took 500 milliseconds 
      This is Method 2
      public void com.github.shehanperera.example.Method.method2() took 1000 milliseconds 
      String :parameters and number :4 and boolean :true
      public void com.github.shehanperera.example.Method.method4(int,java.lang.String,boolean) took 1 milliseconds 
      public static void com.github.shehanperera.example.Sample.main(java.lang.String[]) took 1522 milliseconds

Simillary we can use all other agents (get-parameters ,constructor-instrument ,add-field,add-method,ignore-class) as above way.
Just copy agnet to javaagent-bytebuddy/samples/example-run/target and run it with agent

java -javaagent:***-1.0-SNAPSHOT.jar -jar example-run-1.0-SNAPSHOT.jar