| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * 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 |
| * |
| * 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 org.apache.htrace.wrappers; |
| |
| import org.apache.htrace.Sampler; |
| import org.apache.htrace.Trace; |
| import org.apache.htrace.TraceScope; |
| |
| import java.lang.reflect.InvocationHandler; |
| import java.lang.reflect.Method; |
| import java.lang.reflect.Proxy; |
| |
| public class TraceProxy { |
| /** |
| * Returns an object that will trace all calls to itself. |
| */ |
| public static <T> T trace(T instance) { |
| return trace(instance, Sampler.ALWAYS); |
| } |
| |
| /** |
| * Returns an object that will trace all calls to itself. |
| */ |
| @SuppressWarnings("unchecked") |
| public static <T, V> T trace(final T instance, final Sampler<V> sampler) { |
| InvocationHandler handler = new InvocationHandler() { |
| @Override |
| public Object invoke(Object obj, Method method, Object[] args) |
| throws Throwable { |
| if (!sampler.next(null)) { |
| return method.invoke(instance, args); |
| } |
| |
| TraceScope scope = Trace.startSpan(method.getName(), Sampler.ALWAYS); |
| try { |
| return method.invoke(instance, args); |
| } catch (Throwable ex) { |
| ex.printStackTrace(); |
| throw ex; |
| } finally { |
| scope.close(); |
| } |
| } |
| }; |
| return (T) Proxy.newProxyInstance(instance.getClass().getClassLoader(), |
| instance.getClass().getInterfaces(), handler); |
| } |
| } |