contrib/agent/src/main/java/io/opencensus/contrib/agent/AgentBuilderListener.java

/*
 * Copyright 2017, OpenCensus Authors
 *
 * Licensed 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
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * 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 io.opencensus.contrib.agent;

import java.util.logging.Level;
import java.util.logging.Logger;
import net.bytebuddy.agent.builder.AgentBuilder;
import net.bytebuddy.description.type.TypeDescription;
import net.bytebuddy.dynamic.DynamicType;
import net.bytebuddy.utility.JavaModule;

/**
 * An {@link AgentBuilder.Listener} which uses {@link java.util.logging} for logging events of
 * interest.
 */
final class AgentBuilderListener implements AgentBuilder.Listener {

  private static final Logger logger = Logger.getLogger(AgentBuilderListener.class.getName());

  @Override
  public void onTransformation(
      TypeDescription typeDescription,
      ClassLoader classLoader,
      JavaModule module,
      boolean loaded,
      DynamicType dynamicType) {
    logger.log(Level.FINE, "{0}", typeDescription);
  }

  @Override
  public void onIgnored(
      TypeDescription typeDescription,
      ClassLoader classLoader,
      JavaModule module,
      boolean loaded) {}

  @Override
  public void onError(
      String typeName,
      ClassLoader classLoader,
      JavaModule module,
      boolean loaded,
      Throwable throwable) {
    logger.log(Level.WARNING, "Failed to handle " + typeName, throwable);
  }

  @Override
  public void onComplete(
      String typeName, ClassLoader classLoader, JavaModule module, boolean loaded) {}

  @Override
  public void onDiscovery(
      String typeName, ClassLoader classLoader, JavaModule module, boolean loaded) {}
}