How to deal w/ module-info.java existing

Hi

We solved the bootstrap instrumentation in all JDKs. Now I want to dig more for JDK 9 - 12. As the module introduced in JDK, although most people don’t use today, I want the plugin mechanism ready to go.

I write a simple test, Main.java

public class Main {
    public static void main(String[] args) throws IOException {
        URL obj = new URL("http://www.baidu.com");
        HttpURLConnection con = (HttpURLConnection)obj.openConnection();

        // optional default is GET
        con.setRequestMethod("GET");
        System.out.println(con.getRequestMethod());
//        con.setChunkedStreamingMode(0);

        //add request header

        int responseCode = con.getResponseCode();
        System.out.println("Response Code : " + responseCode);

        BufferedReader in = new BufferedReader(
            new InputStreamReader(con.getInputStream()));
        String inputLine;
        StringBuffer response = new StringBuffer();

        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
        in.close();

        //print result
        System.out.println(response.toString());
    }
}

Empty module-info.java

module JRE.test {
}

After I installed the agent, in JDK 9 -12, it shows the following error

• Do bootstrap instrumentation

ERROR 2019-08-01 14:24:38:322 main SkyWalkingAgent :  SkyWalking agent inject bootstrap instrumentation failure. Shutting down. 
java.lang.UnsupportedOperationException: Could not access Unsafe class: sun.misc.Unsafe
	at org.apache.skywalking.apm.dependencies.net.bytebuddy.dynamic.loading.ClassInjector$UsingUnsafe$Dispatcher$Unavailable.initialize(ClassInjector.java:2033)
	at org.apache.skywalking.apm.dependencies.net.bytebuddy.dynamic.loading.ClassInjector$UsingUnsafe.injectRaw(ClassInjector.java:1765)
	at org.apache.skywalking.apm.agent.core.plugin.bootstrap.BootstrapInstrumentBoost.inject(BootstrapInstrumentBoost.java:102)
	at org.apache.skywalking.apm.agent.SkyWalkingAgent.premain(SkyWalkingAgent.java:103)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:564)
	at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndStartAgent(InstrumentationImpl.java:500)
	at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndCallPremain(InstrumentationImpl.java:512)

• Do simple Main function instrumentation

DEBUG 2019-08-01 14:26:48:650 main SkyWalkingAgent :  On Transformation class a.Main. 
Exception in thread "main" java.lang.ExceptionInInitializerError
Caused by: java.lang.reflect.InvocationTargetException
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:564)
	at JRE.test/a.Main.<clinit>(Main.java)
Caused by: java.lang.reflect.InvocationTargetException
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:564)
	at org.apache.skywalking.apm.dependencies.net.bytebuddy.dynamic.Nexus.initialize(Nexus.java:137)
	... 5 more
Caused by: java.lang.UnsupportedOperationException: Cannot get package using reflection: sun.misc.Unsafe
	at org.apache.skywalking.apm.dependencies.net.bytebuddy.dynamic.loading.ClassInjector$UsingReflection$Dispatcher$Initializable$Unavailable.getPackage(ClassInjector.java:418)
	at org.apache.skywalking.apm.dependencies.net.bytebuddy.dynamic.loading.ClassInjector$UsingReflection.injectRaw(ClassInjector.java:220)
	at org.apache.skywalking.apm.dependencies.net.bytebuddy.dynamic.loading.ClassInjector$AbstractBase.inject(ClassInjector.java:112)
	at org.apache.skywalking.apm.dependencies.net.bytebuddy.agent.builder.AgentBuilder$InitializationStrategy$SelfInjection$Dispatcher$InjectingInitializer.onLoad(AgentBuilder.java:3143)
	... 10 more

How should I avoid these? And make the plugin works if user turns module definition on?

[raphw]

I think that I will include a workaround for the unavailability of jdk.unsupported and make a release after that. I have also registered an issue with OpenJDK for this phenomenon: https://bugs.openjdk.java.net/browse/JDK-8229121

I’d say that I release 1.10.1 some time at the end of August.

[raphw]

Glad it works for you. I just released a new version.