| /* |
| * 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.zpages; |
| |
| import com.google.common.annotations.VisibleForTesting; |
| import com.google.common.base.Splitter; |
| import com.sun.net.httpserver.HttpExchange; |
| import com.sun.net.httpserver.HttpHandler; |
| import io.opencensus.common.Scope; |
| import io.opencensus.trace.AttributeValue; |
| import io.opencensus.trace.Tracer; |
| import io.opencensus.trace.Tracing; |
| import java.io.IOException; |
| import java.net.URI; |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.List; |
| import java.util.Map; |
| |
| /** An {@link HttpHandler} that can be used to render HTML pages using any {@code ZPageHandler}. */ |
| final class ZPageHttpHandler implements HttpHandler { |
| private static final Tracer tracer = Tracing.getTracer(); |
| private static final String HTTP_SERVER = "HttpServer"; |
| private final ZPageHandler zpageHandler; |
| private final String httpServerSpanName; |
| |
| /** Constructs a new {@code ZPageHttpHandler}. */ |
| ZPageHttpHandler(ZPageHandler zpageHandler) { |
| this.zpageHandler = zpageHandler; |
| this.httpServerSpanName = HTTP_SERVER + zpageHandler.getUrlPath(); |
| Tracing.getExportComponent() |
| .getSampledSpanStore() |
| .registerSpanNamesForCollection(Arrays.asList(httpServerSpanName)); |
| } |
| |
| @Override |
| public final void handle(HttpExchange httpExchange) throws IOException { |
| try (Scope ss = |
| tracer |
| .spanBuilderWithExplicitParent(httpServerSpanName, null) |
| .setRecordEvents(true) |
| .startScopedSpan()) { |
| tracer |
| .getCurrentSpan() |
| .putAttribute( |
| "/http/method ", |
| AttributeValue.stringAttributeValue(httpExchange.getRequestMethod())); |
| httpExchange.sendResponseHeaders(200, 0); |
| zpageHandler.emitHtml( |
| uriQueryToMap(httpExchange.getRequestURI()), httpExchange.getResponseBody()); |
| } finally { |
| httpExchange.close(); |
| } |
| } |
| |
| @VisibleForTesting |
| static Map<String, String> uriQueryToMap(URI uri) { |
| String query = uri.getQuery(); |
| if (query == null) { |
| return Collections.emptyMap(); |
| } |
| Map<String, String> result = new HashMap<String, String>(); |
| for (String param : Splitter.on("&").split(query)) { |
| List<String> splits = Splitter.on("=").splitToList(param); |
| if (splits.size() > 1) { |
| result.put(splits.get(0), splits.get(1)); |
| } else { |
| result.put(splits.get(0), ""); |
| } |
| } |
| return result; |
| } |
| } |