tracelytics java api example

WebServer.java

package jon.trace;

import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.InetSocketAddress;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.concurrent.Executors;

import com.sun.net.httpserver.Headers;
import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpServer;
import com.tracelytics.api.LogMethod;
import com.tracelytics.api.Trace;
import com.tracelytics.api.TraceEvent;

public class WebServer {
	public static void main(String[] args) throws IOException {
		int port = 8000;
		InetSocketAddress addr = new InetSocketAddress(port);
		HttpServer server = HttpServer.create(addr, 0);

		server.createContext("/", new MyHandler());
		server.setExecutor(Executors.newCachedThreadPool());
		server.start();
		System.out.println("Server is listening on port " + port);
	}
}

class MyHandler implements HttpHandler {

	@LogMethod(layer = "internal-ops")
	public long expensiveOperation() {
		return randomSleep();
	}

	private long randomSleep() {
		long sleepTime = System.currentTimeMillis() % 100;
		try {
			Thread.sleep(sleepTime);
		} catch (InterruptedException e) {

		}
		return sleepTime;
	}

	public long mongoQuery(String cluster) {
		String eventName = "mongo." + cluster;
		TraceEvent entryEvent = Trace.createEntryEvent(eventName);
		entryEvent.addInfo("Query", "find({uid:672})", 
					  "Flavor", "mongodb",
					  "Collection", cluster);
		entryEvent.report();
		long sleepTime = randomSleep();
		
		Trace.createExitEvent(eventName).report();
		return sleepTime;
	}

	public void handle(HttpExchange exchange) throws IOException {

		String appLayerName = "java-app";

		String requestMethod = exchange.getRequestMethod();
		if (requestMethod.equalsIgnoreCase("GET")) {
			Headers responseHeaders = exchange.getResponseHeaders();
			responseHeaders.set("Content-Type", "text/plain");
			exchange.sendResponseHeaders(200, 0);

			OutputStream responseBody = exchange.getResponseBody();
			PrintWriter pout = new PrintWriter(responseBody);
			Headers requestHeaders = exchange.getRequestHeaders();
			List<String> xtraceValues = requestHeaders.get("X-trace");
			TraceEvent event = null;
			String incomingXtrace = null;
			if (xtraceValues != null && !xtraceValues.isEmpty()) {
				incomingXtrace = xtraceValues.get(0);
				pout.println("Continuing the trace: " + incomingXtrace);
				event = Trace.continueTrace(appLayerName, incomingXtrace);
			} else {
				event = Trace.createEntryEvent(appLayerName);
			}
			event.addInfo("Controller", "catch-all", "Action", "foo");
			event.report();

			Set<String> keySet = requestHeaders.keySet();
			Iterator<String> iter = keySet.iterator();
			while (iter.hasNext()) {
				String key = iter.next();
				List values = requestHeaders.get(key);
				pout.println(key + " = " + values);
			}

			pout.println("Checkins query took " + mongoQuery("checkins"));
			pout.println("Expensive op took " + expensiveOperation());
			pout.println("Users query took " + mongoQuery("users"));

			Trace.createExitEvent(appLayerName).report();
			if (incomingXtrace != null) {						
				Trace.endTrace(appLayerName);
			}
			
			pout.close();
			responseBody.close();
		}
	}
}