content: /*
   * Copyright The OpenTelemetry Authors
   * SPDX-License-Identifier: Apache-2.0
   */
  
  package io.opentelemetry.javaagent.instrumentation.jsp;
  
  import static io.opentelemetry.javaagent.extension.matcher.AgentElementMatchers.hasClassesNamed;
  import static io.opentelemetry.javaagent.extension.matcher.AgentElementMatchers.implementsInterface;
  import static io.opentelemetry.javaagent.instrumentation.jsp.HttpJspPageInstrumentationSingletons.instrumenter;
  import static net.bytebuddy.matcher.ElementMatchers.isPublic;
  import static net.bytebuddy.matcher.ElementMatchers.named;
  import static net.bytebuddy.matcher.ElementMatchers.takesArgument;
  
  import io.opentelemetry.context.Context;
  import io.opentelemetry.context.Scope;
  import io.opentelemetry.javaagent.bootstrap.Java8BytecodeBridge;
  import io.opentelemetry.javaagent.extension.instrumentation.TypeInstrumentation;
  import io.opentelemetry.javaagent.extension.instrumentation.TypeTransformer;
  import javax.servlet.http.HttpServletRequest;
  import net.bytebuddy.asm.Advice;
  import net.bytebuddy.description.type.TypeDescription;
  import net.bytebuddy.matcher.ElementMatcher;
  
  public class HttpJspPageInstrumentation implements TypeInstrumentation {
  
    @Override
    public ElementMatcher<ClassLoader> classLoaderOptimization() {
      return hasClassesNamed("javax.servlet.jsp.HttpJspPage");
    }
  
    @Override
    public ElementMatcher<TypeDescription> typeMatcher() {
      return implementsInterface(named("javax.servlet.jsp.HttpJspPage"));
    }
  
    @Override
    public void transform(TypeTransformer transformer) {
      transformer.applyAdviceToMethod(
          named("_jspService")
              .and(takesArgument(0, named("javax.servlet.http.HttpServletRequest")))
              .and(takesArgument(1, named("javax.servlet.http.HttpServletResponse")))
              .and(isPublic()),
          HttpJspPageInstrumentation.class.getName() + "$HttpJspPageAdvice");
    }
  
    @SuppressWarnings("unused")
    public static class HttpJspPageAdvice {
  
      @Advice.OnMethodEnter(suppress = Throwable.class)
      public static void onEnter(
          @Advice.Argument(0) HttpServletRequest req,
          @Advice.Local("otelContext") Context context,
          @Advice.Local("otelScope") Scope scope) {
        Context parentContext = Java8BytecodeBridge.currentContext();
        if (!instrumenter().shouldStart(parentContext, req)) {
          return;
        }
  
        context = instrumenter().start(parentContext, req);
        scope = context.makeCurrent();
      }
  
      @Advice.OnMethodExit(onThrowable = Throwable.class, suppress = Throwable.class)
      public static void stopSpan(
          @Advice.Argument(0) HttpServletRequest req,
          @Advice.Thrown Throwable throwable,
          @Advice.Local("otelContext") Context context,
          @Advice.Local("otelScope") Scope scope) {
        if (scope == null) {
          return;
        }
  
        scope.close();
        instrumenter().end(context, req, null, throwable);
      }
    }
  }
  