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Add Prometheus Metrics Endpoint to Java App Using Jax-Rs

I’m trying to add a Prometheus metrics exporter to my Java app. The app is currently using javax.ws.rs to define REST endpoints.
For example:
Import javax.ws.rs.*;
Import javax.ws.rs.core.MediaType;
Import javax.ws.rs.core.Response;
#GET
#Path(“/example”)
#Timed
Public Response example(#QueryParam(“id”) Integer id) {
return Response.ok(“testing”)
}
All the examples I found for setting up Prometheus in Java are using Spring. They suggest the following:
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import io.prometheus.client.exporter.HTTPServer;
import java.io.IOException;
#SpringBootApplication
public class App {
public static void main(String[] args) {
SpringApplication.run(App.class, args);
try {
HTTPServer server = new HTTPServer(8081);
} catch (IOException e) { e.printStackTrace(); }
}
}
Is there a way I can simply define a new endpoint in my current setup, for example:
#GET
#Path(“/metrics”)
#Timed
Public Response example {
return Response.ok(“return prom metrics here”)
}
Without having to introduce Spring into the stack?

This can be done as follows:
import io.prometheus.client.Counter;
import io.prometheus.client.CollectorRegistry;
import io.prometheus.client.exporter.TextFormat;
CollectorRegistry registry = new CollectorRegistry();
Counter exCounter = Counter.build().name(“example”).register(registry);
#GET
#Path(“/metrics”)
Public String getMetrics() {
Writer writer = new StringWriter();
try {
TextFormat.write004(writer, registry.metricFamilySamples());
return writer.toString();
} catch (IOException e) {
return “error”;
}
}

vertx get to external address

Hi I'm trying to make a request to external service with the use of httpClient vert.x but I keep getting error: Search domain query failed. Original hostname: 'google.com' failed to resolve 'google.com'
What am i missing in the code below? I'm not sure about those AddressResolverOptions, I have read about them but still I'm not sure what they are responsible for. I'd like to make the request the simplest possible way but the more I investigate the more difficult it seems
package io.vertx.starter;
import io.vertx.core.Vertx;
import io.vertx.core.VertxOptions;
import io.vertx.core.dns.AddressResolverOptions;
import io.vertx.core.http.HttpClientOptions;
import io.vertx.ext.unit.Async;
import io.vertx.ext.unit.TestContext;
import io.vertx.ext.unit.junit.VertxUnitRunner;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import java.net.URL;
import java.util.Collections;
#RunWith(VertxUnitRunner.class)
public class MainVerticleTest {
private Vertx vertx;
#Before
public void setUp(TestContext tc) {
vertx = Vertx.vertx(new VertxOptions().setAddressResolverOptions(
new AddressResolverOptions().addSearchDomain("google.com").addSearchDomain("bar.com"))
);
// vertx = Vertx.vertx();
vertx.deployVerticle(MainVerticle.class.getName(), tc.asyncAssertSuccess());
}
#After
public void tearDown(TestContext tc) {
vertx.close(tc.asyncAssertSuccess());
}
#Test
public void testThatTheServerIsStarted(TestContext tc) {
final HttpClientOptions httpClientOptions = new HttpClientOptions();
httpClientOptions.setConnectTimeout(300);
httpClientOptions.setIdleTimeout(5);
// httpClientOptions.` `
httpClientOptions.setSsl(true).setTrustAll(true);
// final URL url = new URL("currentUrl");
Async async = tc.async();
vertx.createHttpClient(httpClientOptions).getNow(
443,"google.com", "/", response -> {
System.out.println(response.statusCode());
async.complete();
});
//
// Async async = tc.async();
// vertx.createHttpClient().getNow(8080, "localhost", "/", response -> {
// tc.assertEquals(response.statusCode(), 200);
// response.bodyHandler(body -> {
// tc.assertTrue(body.length() > 0);
// async.complete();
// });
// });
}
}

Why does this ID-selection not work in Jsoup?

I am trying to get data from a webpage (http://steamcommunity.com/id/Winning117/games/?tab=all) using a specific tag but I keep getting null. My desired result is to get the "hours played" for a specific game - Cluckles' Adventure in this case.
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
public class TestScrape {
public static void main(String[] args) throws Exception {
String url = "http://steamcommunity.com/id/Winning117/games/?tab=all";
Document document = Jsoup.connect(url).get();
Element playTime = document.select("div#game_605250").first();
System.out.println(playTime);
}
}
Edit: How can I tell if a webpage is using JavaScript and is therefore unable to be parsed by Jsoup?

To execute javascript in java code there is Selenium :
Selenium-WebDriver makes direct calls to the browser using each
browser’s native support for automation.
To include it with maven use this dependency:
<dependency>
<groupId>org.seleniumhq.selenium</groupId>
<artifactId>selenium-server</artifactId>
<version>3.4.0</version>
</dependency>
Next I give you code of simple JUnit test that creates instance of WebDriver and goes to given url and executes simple script to get rgGames .
File chromedriver you have to download at https://sites.google.com/a/chromium.org/chromedriver/downloads.
package SeleniumProject.selenium;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Map;
import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;
import org.openqa.selenium.By;
import org.openqa.selenium.JavascriptExecutor;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriverService;
import org.openqa.selenium.chrome.ChromeOptions;
import org.openqa.selenium.remote.DesiredCapabilities;
import org.openqa.selenium.remote.RemoteWebDriver;
import org.openqa.selenium.support.ui.ExpectedCondition;
import org.openqa.selenium.support.ui.WebDriverWait;
import junit.framework.TestCase;
#RunWith(JUnit4.class)
public class ChromeTest extends TestCase {
private static ChromeDriverService service;
private WebDriver driver;
#BeforeClass
public static void createAndStartService() {
service = new ChromeDriverService.Builder()
.usingDriverExecutable(new File("D:\\Downloads\\chromedriver_win32\\chromedriver.exe"))
.withVerbose(false).usingAnyFreePort().build();
try {
service.start();
} catch (IOException e) {
System.out.println("service didn't start");
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#AfterClass
public static void createAndStopService() {
service.stop();
}
#Before
public void createDriver() {
ChromeOptions chromeOptions = new ChromeOptions();
DesiredCapabilities capabilities = DesiredCapabilities.chrome();
capabilities.setCapability(ChromeOptions.CAPABILITY, chromeOptions);
driver = new RemoteWebDriver(service.getUrl(), capabilities);
}
#After
public void quitDriver() {
driver.quit();
}
#Test
public void testJS() {
JavascriptExecutor js = (JavascriptExecutor) driver;
// Load a new web page in the current browser window.
driver.get("http://steamcommunity.com/id/Winning117/games/?tab=all");
// Executes JavaScript in the context of the currently selected frame or
// window.
ArrayList<Map> list = (ArrayList<Map>) js.executeScript("return rgGames;");
// Map represent properties for one game
for (Map map : list) {
for (Object key : map.keySet()) {
// take each key to find key "name" and compare its vale to
// Cluckles' Adventure
if (key instanceof String && key.equals("name") && map.get(key).equals("Cluckles' Adventure")) {
// print all properties for game Cluckles' Adventure
map.forEach((key1, value) -> {
System.out.println(key1 + " : " + value);
});
}
}
}
}
}
As you can see selenium loads page at
driver.get("http://steamcommunity.com/id/Winning117/games/?tab=all");
And to get data of all games by Winning117 it returns rgGames variable:
ArrayList<Map> list = (ArrayList<Map>) js.executeScript("return rgGames;");

The page you want to scrape is load by js,and there is not any #game_605250 element that jsoup get.All datas are write in page by using js.
But when I print document to a file ,I see some data like this:
<script language="javascript">
var rgGames = [{"appid":224260,"name":"No More Room in Hell","logo":"http:\/\/cdn.steamstatic.com.8686c.com\/steamcommunity\/public\/images\/apps\/224260\/670e9aba35dc53a6eb2bc686d302d357a4939489.jpg","friendlyURL":224260,"availStatLinks":{"achievements":true,"global_achievements":true,"stats":false,"leaderboards":false,"global_leaderboards":false},"hours_forever":"515","last_played":1492042097},{"appid":241540,"name":"State of Decay","logo":"http:\/\/....
then,you can extract 'rgGames' by some StringTools and format it to json obj.
It't not a clerver method,but it worked

try this :
public class TestScrape {
public static void main(String[] args) throws Exception {
String url = "http://steamcommunity.com/id/Winning117/games/?tab=all";
Document document = Jsoup.connect(url).get();
Element playTime = document.select("div#game_605250");
Elements val = playTime.select(".hours_played");
System.out.println(val.text());
}
}

Server sent event client is not working in Java project

I am trying to implement SSE client in java from this tutorial.
It is working fine when implemented as Servlet client using post method.But it is not working when I am implementing the same in Java project using main method and with same jar files as in servlet.Here is the code I am using along with target URI:-
import javax.ws.rs.Consumes;
import javax.ws.rs.ProcessingException;
import javax.ws.rs.client.Client;
import javax.ws.rs.client.ClientBuilder;
import javax.ws.rs.client.WebTarget;
import javax.ws.rs.core.MediaType;
import org.glassfish.jersey.media.sse.EventListener;
import org.glassfish.jersey.media.sse.EventSource;
import org.glassfish.jersey.media.sse.InboundEvent;
import org.glassfish.jersey.media.sse.SseFeature;
public class SSEreceive {
public static void main(String[] args) {
// TODO Auto-generated method stub
try {
Client client = ClientBuilder.newBuilder().register(SseFeature.class).build();
WebTarget target = ((Client)client).target("http://www.w3schools.com/html/demo_sse.php");
EventSource eventSource = (EventSource)EventSource.target(target).build();
EventListener listener = new EventListener() {
#Override
//#Consumes(MediaType.APPLICATION_JSON)
public void onEvent(InboundEvent inboundEvent) {
// System.out.println(inboundEvent.getName() + "; " + inboundEvent.readData(String.class));
System.out.println(inboundEvent.readData(String.class));
}
};
//eventSource.register(listener, "message-to-client");
eventSource.register(listener);
eventSource.open();
System.out.println("Connection tried");
eventSource.close();
} catch (ProcessingException pe) {
pe.printStackTrace();
System.out.println(pe.getMessage());
} catch (Exception e) {
e.printStackTrace();
System.out.println(e.getMessage());
}
}
}
Can some please help me why this is not working in Java project ?

HtmlUnit xpath getElement

I am trying to create a web content crawler for a specific website
http://v1000.vn/bang-xep-hang?ref=bang-xep-hang-1000-doanh-nghiep-dong-thue-thu-nhap-nhieu-nhat-2012
Shortly, my XPath to find the link that change the page (using javascript) is not working which cause NullPointExecetion. I have tried to modify the XPath in various way but nothing worked.
Also, do I need to run any method to get the new page after the script run?
> package gimasys.webService;
import java.io.IOException;
import java.net.MalformedURLException;
import com.gargoylesoftware.htmlunit.BrowserVersion;
import com.gargoylesoftware.htmlunit.FailingHttpStatusCodeException;
import com.gargoylesoftware.htmlunit.ThreadedRefreshHandler;
import com.gargoylesoftware.htmlunit.WebClient;
import com.gargoylesoftware.htmlunit.html.HtmlAnchor;
import com.gargoylesoftware.htmlunit.html.HtmlButton;
import com.gargoylesoftware.htmlunit.html.HtmlLink;
import com.gargoylesoftware.htmlunit.html.HtmlPage;
public class Crawlv1000 {
/**
* #param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
final WebCrawler wc = new WebCrawler();
final PageCrawler pc = new PageCrawler();
final WebClient webClient = new WebClient(BrowserVersion.CHROME_16);
webClient.setRefreshHandler(new ThreadedRefreshHandler()); // This is to allow handling the page operation using threads else an exception will pop up
try {
HtmlPage page = webClient.getPage("http://v1000.vn/bang-xep-hang?ref=bang-xep-hang-1000-doanh-nghiep-dong-thue-thu-nhap-nhieu-nhat-2012");
HtmlAnchor link = page.getFirstByXPath("//a[#href='javascript:loadRankingTable(3)']");
link.click();
System.out.println(page.getTextContent());
} catch (FailingHttpStatusCodeException | IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
/*
wc.crawl("http://v1000.vn/bang-xep-hang?ref=bang-xep-hang-1000-doanh-nghiep-dong-thue-thu-nhap-nhieu-nhat-2012");
for (String url:wc.urlList)
{
pc.crawl(url);
}
*/
}
}
Thanks,
Minh Nguyen

Very small mistake done by you dear, semicolon mistake
HtmlAnchor link = page.getFirstByXPath("//a[#href='javascript:loadRankingTable(3);']");
link.click();