Instrument JDK class, such as HttpURLConnection

[vinodkumar21]

Please answer these questions before submitting your issue.

• Why do you submit this issue?
• Bug

---

Question

• What do you want to know?
  I developed code using java.net.HttpURLConnection.HttpURLConnection . i want to trace http request using skywaling-apm.
  but skywalking-agent not capturing logs.

Bug

• Which version of SkyWalking, OS and JRE?
  6.0.1
• Which company or project?
  Spice digital Ltd

[wu-sheng]

Because we don't provide a mechanism to intercept JDK classes. We prefer to intercept the 3rd party library.

[vinodkumar21]

HI,
can you share link for 3rd party library.

[wu-sheng]

For the libraries, we supported, check here, https://github.com/apache/skywalking/blob/master/docs/en/setup/service-agent/java-agent/Supported-list.md

[vinodkumar21]

please share plugin name which can help us.there are lot of plugin

[wu-sheng]

That is plugin list we supported. java.net.HttpURLConnection.HttpURLConnection is not on the list. If you are using that directly, the short answer is we can't trace it today.

[vinodkumar21]

I developed same using custom plugin but its not working.below is my code,can you where i am wrong.

/*

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• contributor license agreements. See the NOTICE file distributed with
• this work for additional information regarding copyright ownership.
• The ASF licenses this file to You under the Apache License, Version 2.0
• (the "License"); you may not use this file except in compliance with
• the License. You may obtain a copy of the License at

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• distributed under the License is distributed on an "AS IS" BASIS,
• WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
• See the License for the specific language governing permissions and
• limitations under the License.

*/

package org.apache.skywalking.apm.plugin.feign.http.v9.define;

import org.apache.skywalking.apm.agent.core.plugin.interceptor.ConstructorInterceptPoint;
import org.apache.skywalking.apm.agent.core.plugin.interceptor.InstanceMethodsInterceptPoint;
import org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.ClassInstanceMethodsEnhancePluginDefine;
import org.apache.skywalking.apm.agent.core.plugin.match.ClassMatch;
import org.apache.skywalking.apm.dependencies.net.bytebuddy.description.method.MethodDescription;
import org.apache.skywalking.apm.dependencies.net.bytebuddy.matcher.ElementMatcher;
import org.apache.skywalking.apm.dependencies.net.bytebuddy.matcher.ElementMatchers;
import org.apache.skywalking.apm.plugin.feign.http.v9.DefaultHttpClientInterceptor;

import static org.apache.skywalking.apm.agent.core.plugin.match.NameMatch.byName;

/**

• {@link DefaultHttpClientInstrumentation} presents that skywalking intercepts {@link

• feign.Client.Default#execute(feign.Request, feign.Request.Options)} by using {@link DefaultHttpClientInterceptor}.

• If feign did't run in default mode, the instrumentation depend on the http discovery implementation.

• e.g. okhttp discovery implementation depend on okhttp-plugin.

• @author peng-yongsheng
  */
  public class DefaultHttpClientInstrumentation extends ClassInstanceMethodsEnhancePluginDefine {

  /**

  • Enhance class.
    */
    private static final String ENHANCE_CLASS = "sun.net.www.protocol.http.HttpURLConnection";

  /**

  • Intercept class.
    */
    private static final String INTERCEPT_CLASS = "org.apache.skywalking.apm.plugin.feign.http.v9.DefaultHttpClientInterceptor";

  @OverRide protected ClassMatch enhanceClass()
  {
  Log.getDebugLogs("http method"+ENHANCE_CLASS);
  System.out.println("http method"+ENHANCE_CLASS);
  return byName(ENHANCE_CLASS);
  }

  @OverRide protected ConstructorInterceptPoint[] getConstructorsInterceptPoints() {
  return new ConstructorInterceptPoint[0];
  }

  @OverRide protected InstanceMethodsInterceptPoint[] getInstanceMethodsInterceptPoints() {
  return new InstanceMethodsInterceptPoint[] {
  new InstanceMethodsInterceptPoint() {
  @OverRide public ElementMatcher getMethodsMatcher()
  {
  Log.getDebugLogs("execute method"+ENHANCE_CLASS);
  System.out.println(".........................................execute method"+ENHANCE_CLASS);
  return ElementMatchers.named("connect");
  }

           @Override public String getMethodsInterceptor() {
               return INTERCEPT_CLASS;
           }
  
           @Override public boolean isOverrideArgs() {
               return false;
           }
       }
   };
  

  }
  }

package org.apache.skywalking.apm.plugin.feign.http.v9;

import java.lang.reflect.Method;
import java.net.HttpURLConnection;
import java.net.URL;
import org.apache.skywalking.apm.agent.core.context.CarrierItem;
import org.apache.skywalking.apm.agent.core.context.ContextCarrier;
import org.apache.skywalking.apm.agent.core.context.ContextManager;
import org.apache.skywalking.apm.agent.core.context.tag.Tags;
import org.apache.skywalking.apm.agent.core.context.trace.AbstractSpan;
import org.apache.skywalking.apm.agent.core.context.trace.SpanLayer;
import org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.EnhancedInstance;
import org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodsAroundInterceptor;
import org.apache.skywalking.apm.agent.core.plugin.interceptor.enhance.MethodInterceptResult;
import org.apache.skywalking.apm.network.trace.component.ComponentsDefine;
import org.apache.skywalking.apm.plugin.feign.http.v9.define.Log;
public class DefaultHttpClientInterceptor
implements InstanceMethodsAroundInterceptor
{
private static final String COMPONENT_NAME = "FeignDefaultHttp";
@OverRide
public void beforeMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes, MethodInterceptResult result)
throws Throwable
{

  System.out.println("------------------before");

/*HttpURLConnection request = (HttpURLConnection)allArguments[0];

URL url = request.getURL();
ContextCarrier contextCarrier = new ContextCarrier();
int port = url.getPort() == -1 ? 80 : url.getPort();
String remotePeer = url.getHost() + ":" + port;
String operationName = url.getPath();
if ((operationName == null) || (operationName.length() == 0)) {
  operationName = "/";
}
AbstractSpan span = ContextManager.createExitSpan(operationName, contextCarrier, remotePeer);
span.setComponent(ComponentsDefine.FEIGN);
Tags.HTTP.METHOD.set(span, request.getRequestMethod());
Tags.URL.set(span, url.toString());
SpanLayer.asHttp(span);*/

/*Field headersField = Request.class.getDeclaredField("headers");*/
/*Field modifiersField = Field.class.getDeclaredField("modifiers");
modifiersField.setAccessible(true);
modifiersField.setInt(headersField, headersField.getModifiers() & 0xFFFFFFEF);*/

// headersField.setAccessible(true);
/Map<String, Collection> headers = new LinkedHashMap();/
/CarrierItem next = contextCarrier.items();
while (next.hasNext())
{
next = next.next();
request.setRequestProperty(next.getHeadKey(), next.getHeadValue());
}/

}
@OverRide
public Object afterMethod(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes, Object ret)
throws Throwable
{
Log.getDebugLogs("-------------------------------------------after http defaul method"+allArguments[0]);
/* HttpURLConnection response = (HttpURLConnection)ret;
if (response != null)
{
int statusCode = response.getResponseCode();

  AbstractSpan span = ContextManager.activeSpan();
  if (statusCode >= 400)
  {
    span.errorOccurred();
    Tags.STATUS_CODE.set(span, statusCode + "");
  }
}
ContextManager.stopSpan();*/

return null;

}

public void handleMethodException(EnhancedInstance objInst, Method method, Object[] allArguments, Class<?>[] argumentsTypes, Throwable t)
{
Log.getDebugLogs("in errror debuger");
t.printStackTrace();
AbstractSpan activeSpan = ContextManager.activeSpan();
activeSpan.log(t);
activeSpan.errorOccurred();
}
}

[wu-sheng]

Because of this

private static final String ENHANCE_CLASS = "sun.net.www.protocol.http.HttpURLConnection";

This is a JRE level class, rt.jar mostly. We don't instrument any class like this. You need to adjust byte-buddy AgentBuilder in SkyWalkingAgent to make it works. I haven't tried that.

[vinodkumar21]

Thanks for the prompt response and clarification, actually I am building this solution for a major customer and this is one of the key requirement, Can you please help me with some documentation to make adjustment in byte-buddy Agentbuilder? This would be of a great help

[wu-sheng]

Thanks for the prompt response and clarification, actually I am building this solution for a major customer and this is one of the key requirement, Can you please help me with some documentation to make adjustment in byte-buddy Agentbuilder? This would be of a great help

I think I don't have this today. You need to read the byte-buddy document. We are welcome the contributions after you made it.