如何使用Bytebuddy检测HttpURLConnection？

Question

I'm using Bytebuddy to intercept some method of HttpURLConnection and add tracing. I've written the following code:

File temp = Files.createTempDirectory("tmp").toFile();
            new AgentBuilder.Default().ignore(none())
                    .enableBootstrapInjection(inst, temp)
                    .type(hasSuperType(is(HttpURLConnection.class)))
                    .transform(new AgentBuilder.Transformer.ForAdvice()
                            .include(HttpURLConnection.class.getClassLoader())
                            .advice(named("setRequestMethod"), HttpURLIntercept.class.getName()))
                    .installOn(inst);

But the method is never instrumented.

I know that HttpURLConnection is loaded on bootstrap. How can I still instrument it?

Answer 1

By default, Byte Buddy ignores the bootstrap class loader. Define a different ignore matcher that does not include HttpUrlConnection to avoid this exclusion. Note that the JVM defines mant thousand classes itself that are all loaded on the bootstrap loader where JVM stsrtup becomes very slow if you do not exclude most bootstrap classes efficiently.