Develop Reference

How to instrument Java application code metrics to Prometheus

I am trying to export customized values metrics of my Java application to Prometheus. I have read that it could be done with Push Gateway, following an example I use the next method:
static void executeBatchJob() throws Exception {
CollectorRegistry registry = new CollectorRegistry();
Gauge duration = Gauge.build()
.name("my_batch_job_duration_seconds").help("Duration of my batch job in seconds.").register(registry);
Gauge.Timer durationTimer = duration.startTimer();
try {
// Your code here.
myCode();
// This is only added to the registry after success,
// so that a previous success in the Pushgateway isn't overwritten on failure.
Gauge lastSuccess = Gauge.build()
.name("my_batch_job_last_success").help("Last time my batch job succeeded, in unixtime.").register(registry);
lastSuccess.setToCurrentTime();
} finally {
durationTimer.setDuration();
PushGateway pg = new PushGateway("172.16.124.40:9091");
pg.pushAdd(registry, "my_batch_job");
}
}
But when I run the project I am having the next error:
Exception in thread "main" java.lang.NoClassDefFoundError: io/prometheus/client/exporter/common/TextFormat
at io.prometheus.client.exporter.PushGateway.doRequest(PushGateway.java:299)
at io.prometheus.client.exporter.PushGateway.pushAdd(PushGateway.java:158)
at nemshelloworld.NemsHelloWorld.executeBatchJob2(NemsHelloWorld.java:78)
at nemshelloworld.NemsHelloWorld.main(NemsHelloWorld.java:33)
Caused by: java.lang.ClassNotFoundException: io.prometheus.client.exporter.common.TextFormat
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:335)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

You're missing the simpleclient_common module, which is a listed dependency of simpleclient_pushgateway so it sounds like your pom.xml or equivalent isn't right.

Avoiding NoClassDefFoundError when using JavaMail [duplicate]

This question already has answers here:
Replacements for deprecated JPMS modules with Java EE APIs
(11 answers)
Closed 4 years ago.
I keep getting the NoClassDefFoundError error. I am trying to send an email using the JavaMail API, but the error occurs when I'm creating an instance of Message using the SMTPMessage class.
I know I need the activation library, but it still doesn't work.
By the way, I'm using JDK 10.
The error happens on the first line of this code.
#Override
public void sendEmail(Mail mail) throws MessagingException
{
Message message = new SMTPMessage(this.session);
message.setSubject(mail.getHeader());
message.setFrom(mail.getFrom());
message.setSentDate(mail.getDateClone());
if (mail.getSignature() != null)
message.setText(mail.getText() + "\n\n" + mail.getSignature());
else
message.setText(mail.getText());
Transport.send(message);
}
Stacktrace
Exception in thread "main" java.lang.NoClassDefFoundError: javax/activation/DataSource
at martin.mail.EmailHandler.sendEmail(EmailHandler.java:79)
at martin.Main.main(Main.java:22)
Caused by: java.lang.ClassNotFoundException: javax.activation.DataSource
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:582)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:190)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:499)
... 2 more

Solution
Just add the activation library to your own class path. You can put it in your own package.

JDK 7/JavaFX 2 application on Mac OSX El Capitan

I've just upgraded to El Capitan and I'm running into problems starting a custom JavaFX2 application running under JDK1.7.0u79 (the latest available from Oracle).
When starting the app, I'm getting this Exception:
Exception in thread "main" java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:403)
at com.sun.javafx.application.LauncherImpl.access$000(LauncherImpl.java:47)
at com.sun.javafx.application.LauncherImpl$1.run(LauncherImpl.java:115)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ExceptionInInitializerError
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:191)
at javafx.scene.control.Control.loadClass(Control.java:115)
at javafx.scene.control.Control.loadSkinClass(Control.java:1021)
at javafx.scene.control.Control.access$500(Control.java:70)
at javafx.scene.control.Control$12.invalidated(Control.java:972)
at javafx.beans.property.StringPropertyBase.markInvalid(StringPropertyBase.java:127)
at javafx.beans.property.StringPropertyBase.set(StringPropertyBase.java:161)
at com.sun.javafx.css.StyleableStringProperty.set(StyleableStringProperty.java:71)
at javafx.scene.control.Control$12.set(Control.java:964)
at com.sun.javafx.css.StyleableStringProperty.applyStyle(StyleableStringProperty.java:59)
at com.sun.javafx.css.StyleableStringProperty.applyStyle(StyleableStringProperty.java:31)
at com.sun.javafx.css.StyleableProperty.set(StyleableProperty.java:70)
at com.sun.javafx.css.StyleHelper.transitionToState(StyleHelper.java:900)
at javafx.scene.Node.impl_processCSS(Node.java:7418)
at javafx.scene.Parent.impl_processCSS(Parent.java:1146)
at javafx.scene.control.Control.impl_processCSS(Control.java:1154)
at javafx.scene.Parent.impl_processCSS(Parent.java:1153)
at javafx.scene.Parent.impl_processCSS(Parent.java:1153)
at javafx.scene.Node.processCSS(Node.java:7386)
at javafx.scene.Scene.doCSSPass(Scene.java:454)
at javafx.scene.Scene.preferredSize(Scene.java:1468)
at javafx.scene.Scene.impl_preferredSize(Scene.java:1535)
at javafx.stage.Window$9.invalidated(Window.java:717)
at javafx.beans.property.BooleanPropertyBase.markInvalid(BooleanPropertyBase.java:127)
at javafx.beans.property.BooleanPropertyBase.set(BooleanPropertyBase.java:161)
at javafx.stage.Window.setShowing(Window.java:781)
at javafx.stage.Window.show(Window.java:796)
at javafx.stage.Stage.show(Stage.java:233)
at au.com.religaresecurities.trademax.client.Start.start(Start.java:131)
at com.sun.javafx.application.LauncherImpl$5.run(LauncherImpl.java:319)
at com.sun.javafx.application.PlatformImpl$5.run(PlatformImpl.java:219)
at com.sun.javafx.application.PlatformImpl$4$1.run(PlatformImpl.java:182)
at com.sun.javafx.application.PlatformImpl$4$1.run(PlatformImpl.java:179)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$4.run(PlatformImpl.java:179)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:76)
Caused by: java.lang.NullPointerException
at com.sun.t2k.MacFontFinder.initPSFontNameToPathMap(MacFontFinder.java:339)
at com.sun.t2k.MacFontFinder.getFontNamesOfFontFamily(MacFontFinder.java:390)
at com.sun.t2k.T2KFontFactory.getFontResource(T2KFontFactory.java:233)
at com.sun.t2k.LogicalFont.getSlot0Resource(LogicalFont.java:184)
at com.sun.t2k.LogicalFont.getSlotResource(LogicalFont.java:228)
at com.sun.t2k.CompositeStrike.getStrikeSlot(CompositeStrike.java:86)
at com.sun.t2k.CompositeStrike.getMetrics(CompositeStrike.java:132)
at com.sun.javafx.font.PrismFontUtils.getFontMetrics(PrismFontUtils.java:31)
at com.sun.javafx.font.PrismFontLoader.getFontMetrics(PrismFontLoader.java:466)
at javafx.scene.text.Text.<init>(Text.java:153)
at javafx.scene.text.Text.<init>(Text.java:162)
at com.sun.javafx.scene.control.skin.ProgressIndicatorSkin.<clinit>(ProgressIndicatorSkin.java:78)
... 37 more
I can't just migrate the app to Java 8, so any help is much appreciated.
Update
I've been able to get the app running again by adding this to the start of my main method. Any better solutions out there?
try {
Class<?> macFontFinderClass = Class.forName("com.sun.t2k.MacFontFinder");
Field psNameToPathMap = macFontFinderClass.getDeclaredField("psNameToPathMap");
psNameToPathMap.setAccessible(true);
psNameToPathMap.set(null, new HashMap<String, String>());
} catch (Exception e) {
// ignore
}

After more than a week with that in an extensive enterprise application, I haven't noticed any problems in the UI.
For the lack of a better solution, I'm accepting my update above as answer. Maybe it helps someone...
I've been able to get the app running again by adding this to the start of my main method.
try {
Class<?> macFontFinderClass = Class.forName("com.sun.t2k.MacFontFinder");
Field psNameToPathMap = macFontFinderClass.getDeclaredField("psNameToPathMap");
psNameToPathMap.setAccessible(true);
psNameToPathMap.set(null, new HashMap<String, String>());
} catch (Exception e) {
// ignore
}

This isn't a direct answer, however I thought it important to pass on that this bug has been identified and fixed in an upcoming Java release. See https://bugs.openjdk.java.net/browse/JDK-8143907

I had the same problem. I changed the Text to a Label. I'm not sure it's possible in your case.

Example of Google's Geocoding API is not working

I wanted to test the GeocodingAPI-example of the googles hompage (the code).
I'm working with Java in eclipse and I already added the library "google-maps-services 0.1.7" to my project. This is my code:
package test;
import com.google.maps.*;
import com.google.maps.model.GeocodingResult;
public class Distance {
public static void main(String[] args) throws Exception {
GeoApiContext context = new GeoApiContext().setApiKey("AIza...");
GeocodingResult[] results = GeocodingApi.geocode(context,
"1600 Amphitheatre Parkway Mountain View, CA 94043").await();
System.out.println(results[0].formattedAddress);
}
}
When I want to run the code, the following problem is shown in the console:
Exception in thread "main" java.lang.NoClassDefFoundError: com/squareup/okhttp/OkHttpClient
at com.google.maps.GeoApiContext.<init>(GeoApiContext.java:50)
at test.Distance.main(Distance.java:10)
Caused by: java.lang.ClassNotFoundException: com.squareup.okhttp.OkHttpClient
at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 2 more
I changed the API to my personal API. What is wrong in this code? Are there mistakes in the import-instructions?

NoClassDefFoundError When trying to use Gmail API to send a email

This is my first time using the Gmail REST API and I'm trying to send an email using it. I followed the instructions on Google Developer site and got the authentication part successful. But now when I'm trying to send a email an Exception is thrown. Complete exception is,
Exception in thread "main" java.lang.NoClassDefFoundError: com/sun/mail/util/MailLogger
at javax.mail.Session.initLogger(Session.java:227)
at javax.mail.Session.<init>(Session.java:212)
at javax.mail.Session.getDefaultInstance(Session.java:315)
at gmailconsole.Email.createEmail(Email.java:45)
at gmailconsole.GmailApiQuickStart.main(GmailApiQuickStart.java:91)
Caused by: java.lang.ClassNotFoundException: com.sun.mail.util.MailLogger
at java.net.URLClassLoader$1.run(URLClassLoader.java:372)
at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308)
at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
... 5 more
The code that associated with the exception
public static void sendMessage(Gmail service, String userId, MimeMessage email)
throws MessagingException, IOException {
Message message = createMessageWithEmail(email);
message = service.users().messages().send(userId, message).execute();
System.out.println("Message id: " + message.getId());
System.out.println(message.toPrettyString());
}
Method call in the main class
try {
MimeMessage mimeMessage = Email.createEmail("isurub1992#gmail.com", "me", "Test", "This is a test message");
Email.sendMessage(service, "me", mimeMessage);
} catch (MessagingException ex) {
ex.printStackTrace();
}
P.S : I have added all the libraries and JavaEE API Library in NetBeasns

ClassNotFoundException is definite: the class is not found in classpath.
Short search reveals that the missing class com.sun.mail.util.MailLogger is found in com.sun.mail_1.4.2.jar; so have a look, I would place a bet that this would solve your problem.
Not the same problem, but it could be a nice information for you, too:
java.lang.NoClassDefFoundError: javax/mail/Authenticator, whats wrong?