Add initial implementation of the tracez page. (#517)

* Add initial implementation of the tracez page.

* Fix HTML when premature return. Add DOCTYPE and charset.

* URLEncode the given spanName.

* Build zpages only for java8.

* Move Tester->ZPagesTester, add tests for query parsing.

* Fix more comments.

2 files changed, 45 insertions, 1 deletions

diff --git a/examples/build.gradle b/examples/build.gradle
index 5e45e846..2e31a145 100644
--- a/examples/build.gradle
+++ b/examples/build.gradle
@@ -8,7 +8,8 @@ tasks.withType(JavaCompile) {
 dependencies {
     compile project(':core'),
             project(':opencensus-api'),
-            project(':opencensus-trace-logging-exporter')
+            project(':opencensus-trace-logging-exporter'),
+            project(':opencensus-zpages')
 
     runtime project(':core_impl_java'),
             project(':opencensus-impl')
@@ -47,10 +48,18 @@ task multiSpansContextTracing(type: CreateStartScripts) {
     classpath = jar.outputs.files + project.configurations.runtime
 }
 
+task zPagesTester(type: CreateStartScripts) {
+    mainClassName = 'io.opencensus.examples.zpages.ZPagesTester'
+    applicationName = 'ZPagesTester'
+    outputDir = new File(project.buildDir, 'tmp')
+    classpath = jar.outputs.files + project.configurations.runtime
+}
+
 applicationDistribution.into('bin') {
     from(multiSpansTracing)
     from(multiSpansScopedTracing)
     from(multiSpansContextTracing)
     from(statsRunner)
+    from(zPagesTester)
     fileMode = 0755
 }
\ No newline at end of file
diff --git a/examples/src/main/java/io/opencensus/examples/zpages/ZPagesTester.java b/examples/src/main/java/io/opencensus/examples/zpages/ZPagesTester.java
new file mode 100644
index 00000000..1d59e3b4
--- /dev/null
+++ b/examples/src/main/java/io/opencensus/examples/zpages/ZPagesTester.java
@@ -0,0 +1,35 @@
+/*
+ * Copyright 2017, Google Inc.
+ * 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.examples.zpages;
+
+import com.sun.net.httpserver.HttpServer;
+import io.opencensus.zpages.TracezHttpHandler;
+import java.net.InetSocketAddress;
+import java.util.logging.Logger;
+
+/**
+ * Testing only class for the UI.
+ */
+public class ZPagesTester {
+  private static final Logger logger = Logger.getLogger(ZPagesTester.class.getName());
+
+  /** Main method. */
+  public static void main(String[] args) throws Exception {
+    HttpServer server = HttpServer.create(new InetSocketAddress(8000), 10);
+    TracezHttpHandler.register(server);
+    server.start();
+    logger.info(server.getAddress().toString());
+  }
+
+}