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Spring boot app error log says attempt to configure ONS in FanManager failed with oracle.ons.NoServersAvailable

I am running a Spring Boot application (v2.2.0-RELEASE) with spring-boot-starter-jdbc and com.oracle.ojdbc:ojdbc8:19.3.0.0 driver.
When I try to query the database using JdbcTemplate I see the following error in the console log:
2019-11-15 14:07:51.154 ERROR 23436 --- [main] oracle.simplefan.FanManager: attempt to configure ONS in FanManager failed with oracle.ons.NoServersAvailable: Subscription time out
I have no clue why I'm seeing this error even though the database connection is successful and query result is correct.
Is there any way to get rid of this error or just ignore?

You can set the system property when starting the application:
-Doracle.jdbc.fanEnabled=false
Or remove the simplefan and ons jars from the classpath. With Maven it might look like this:
<dependency>
<groupId>com.oracle.database.jdbc</groupId>
<artifactId>ojdbc10</artifactId>
<version>${oracle.version}</version>
<exclusions>
<exclusion>
<groupId>com.oracle.database.ha</groupId>
<artifactId>simplefan</artifactId>
</exclusion>
<exclusion>
<groupId>com.oracle.database.ha</groupId>
<artifactId>ons</artifactId>
</exclusion>
</exclusions>
</dependency>
More details in Section 29.3 of the Oracle's JDBC Developer's guide "Installation and Configuration of Oracle JDBC Driver for FAN Events Support".

For removing the jars with maven Antoni's answer might not work for you if the group id for the jars is not identical (different ojdbc version for example). You need to find these group ids. For example I use ojdbc8, looking at the used libraries in my IDE (Idea here) I can see the groupId of ons and simplefan (here com.oracle.jdbc)
Now I only need to put the appropriate Ids for exclusion (here the example is for ojdbc 8)
<dependency>
<groupId>com.oracle.ojdbc</groupId>
<artifactId>ojdbc8</artifactId>
<exclusions>
<exclusion>
<groupId>com.oracle.ojdbc</groupId>
<artifactId>simplefan</artifactId>
</exclusion>
<exclusion>
<groupId>com.oracle.ojdbc</groupId>
<artifactId>ons</artifactId>
</exclusion>
</exclusions>
</dependency>

remove the simplefan.jar and ons.jars from the ojdbc8 library

JDK 10 cannot import javax.xml.namespace in Eclipse

It's very strange. I am moving a dynamic web project from Java 8 to Java 10.
The last thing I cannot get the dependency resolved is the javax.xml.namespace.QName class.
You can see in the attached screen shot, the QName class exist in JRE System Library, but the IDE keep complaining that QName cannot be resolved to a type.

There probably is a duplicate dependency pulled in from some other dependency.
In eclipse do
"Navivate -> Open Type..."
Type in "java.xml.namespace".
If there are other results than from your (Open-)JDK, these need to be removed in the following steps. In my case it was xml-apis
Open your pom.xml in eclipse, and visit the "Dependency Hierarchy" tab to check which dependency was pulling in xml-apis
Type "xml-apis" in the Filter. In my case the top level dependency that was pulling xml-apis was "esapi"
exclude xml-apis from the esapi dependency:
<dependency>
<groupId>org.owasp.esapi</groupId>
<artifactId>esapi</artifactId>
<version>2.2.0.0</version>
<exclusions>
<exclusion>
<groupId>xml-apis</groupId>
<artifactId>xml-apis</artifactId>
</exclusion>
</exclusions>
</dependency>
Right click your Project and choose "Maven -> Update Project...". Check your project and click OK.
That's it

I had the same error moving from Java 8 to Java 11,
and I included an explicit dependency on the library stax-api 1.0-2:
<dependency>
<groupId>javax.xml.stream</groupId>
<artifactId>stax-api</artifactId>
<version>1.0-2</version>
</dependency>
and excluded any transitional dependency on the library stax-api 1.0.1:
...
<exclusion>
<groupId>stax</groupId>
<artifactId>stax-api</artifactId>
</exclusion>
...
After this, my IDE found the lost import javax.xml.namespace.QName correctly.
I hope this helps.

Try to change the order of elements on your classpath. The JRE must be before the Maven Dependencies. That fixes the issue.
My guess is that the Java 10 compiler notices that you're trying to replace internal classes (java.xml.namespace) with code from JARs and it doesn't like that.

Resolved it by removing jsr173_api.jar from the project classpath (project -> properties -> java build path -> libraries -> classpath). It appears again when eclipse project rebuilt.

This worked! Checking for multipletypes Ctrl+Shift+T, removing unwanted ones.

I have had the same experience with the JRE 11, and Gradle 7.5. If it helps anyone, you can exclude xml-apis as such:
configurations {
all {
exclude group: 'xml-apis', module: 'xml-apis'
}
}

no such method jsch.JSch.setLogger

The below behavior occurs when i call the getSftpUtil(). I have also ensured that all the appropriate jars are in the maven project's external libraries and are available in the WEB-INF/lib folder of the project
code
net.sf.opensftp.SftpUtil util = SftpUtilFactory.getSftpUtil();
stacktrace
SftpUtilFactory: Trying to get SftpUtil class name from the system property net.sf.opensftp.SftpUtil
SftpUtilFactory - Trying to get SftpUtil class name from the system property net.sf.opensftp.SftpUtil
SftpUtilFactory: The system property net.sf.opensftp.SftpUtil is not set.
SftpUtilFactory - The system property net.sf.opensftp.SftpUtil is not set.
SftpUtilFactory: Use the default one.
SftpUtilFactory - Use the default one.
Caused by: java.lang.NoSuchMethodError: com.jcraft.jsch.JSch.setLogger(Lcom/jcraft/jsch/Logger;)V
at net.sf.opensftp.impl.SftpUtil.<clinit>(SftpUtil.java:110)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at net.sf.opensftp.SftpUtilFactory.getSftpUtil(SftpUtilFactory.java:184)

Based on jcraft's change log, setLogger is a method added to JSch.java in jsch-0.1.30. So the jar under your WEB-INF/lib should be an older version.
You can run
mvn dependency:tree
to see which of your dependencies is using the older version, and then exclude it with something like this:
<dependency>
<groupId>...</groupId>
<artifactId>...</artifactId>
<version>...</version>
<exclusions>
<exclusion>
<groupId>com.jcraft</groupId>
<artifactId>jsch</artifactId>
</exclusion>
</exclusions>
</dependency>
You probably have another dependency refer to a more recent version of jsch, so your problem should be solved at this point. However, if that's not the case, you can add this to pom.xml:
<dependency>
<groupId>com.jcraft</groupId>
<artifactId>jsch</artifactId>
<version>0.1.50</version>
</dependency>

Well, I guess you are missing this dependency or the proper version:
<groupId>com.jcraft</groupId>
<artifactId>jsch</artifactId>
<version>0.1.49</version> <!--latest version -->

Getting java.lang.NoClassDefFoundError: org/bouncycastle/asn1/DEREncodable during PDF Encryption [duplicate]

I'm trying to use iText Java.
When you run the example "how to sign" the following error occurs:
Caused by: java.lang.ClassNotFoundException: org.bouncycastle.tsp.TimeStampTokenInfo
According "Getting Started with iText - How to sign a PDF using iText", I have to use the BouncyCastle.
I downloaded the file: bcprov-jdk15on-147.jar from BouncyCastle download page.
And added to the project: Java Build Path/Libraries/Add External JARs...
I added the following line:
Security.addProvider(new BouncyCastleProvider());
When you run the example the same error occurs.
So I downloaded another file: bcpkix-jdk15on-147.jar entitled "PKIX/CMS/EAC/PKCS/OCSP/TSP/OPENSSL"
And added to the project: Java Build Path/Libraries/Add External JARs...
Now I have two Jars.
When you run the example the following error occurs:
Caused by: java.lang.ClassNotFoundException: org.bouncycastle.asn1.DEREncodable
I tried downloading the file "bcprov-ext-jdk15on-147.jar" but did not solve the problem.
I am using iText 5.2.1 and eclipse on Windows 7 64 bits.

iText marks bouncycastle dependencies as optional. If you require them, you need to add the dependencies in your own pom file.
To find out which dependency to include in your project, open the itextpdf pom.xml file of the version you are using (for example 5.3.2, here) and search for the 2 bouncycastle dependencies.
<dependency>
<groupId>org.bouncycastle</groupId>
<artifactId>bcprov-jdk15on</artifactId>
<version>1.47</version>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.bouncycastle</groupId>
<artifactId>bcmail-jdk15on</artifactId>
<version>1.47</version>
<optional>true</optional>
</dependency>
Copy them into your pom file and remove the optional option.
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>itextpdf</artifactId>
<version>5.3.2</version>
</dependency>
<dependency>
<groupId>org.bouncycastle</groupId>
<artifactId>bcprov-jdk15on</artifactId>
<version>1.47</version>
</dependency>
<dependency>
<groupId>org.bouncycastle</groupId>
<artifactId>bcmail-jdk15on</artifactId>
<version>1.47</version>
</dependency>

BouncyCastle libs are undergoing heavy API changes that broke the compatibility with other libs like iText.
Either
use a previous version of BouncyCastle libs. Old versions can be found here. However, you'll have to find the right version of iText that was compatible with this particular version of BC.
make your own build of iText (the SVN trunk has been fixed). iText can be build with Maven (there's a short readme file at the root of the SVN). Please note that it's at your own risk, there may be bugs in trunk.
wait for the next version of iText. From my experience, iText releases come every couple of months, sometime more often, sometimes less. I'm not an iText committer though, so I can't give you any ETA.
More information can be found in this thread

With itextpdf version 5.5.4 org.bouncycastle dependencies are marked as <optional>true</optional>. This means you MUST include those dependencies in your own pom, or you can run into classnotfound exceptions.
<dependency>
<groupId>com.itextpdf</groupId>
<artifactId>itextpdf</artifactId>
<version>5.5.4</version>
</dependency>
<!-- Bouncycastle dependencies necessary as they are optional = true
in itextpdf ... but they're not-so-optional in reality -->
<dependency>
<groupId>org.bouncycastle</groupId>
<artifactId>bcprov-jdk15on</artifactId>
<version>1.49</version>
</dependency>
<dependency>
<groupId>org.bouncycastle</groupId>
<artifactId>bcpkix-jdk15on</artifactId>
<version>1.49</version>
</dependency>

from version of bcprov-jdk15on-147, class of DEREncodable is no longer exist under the path of org.bouncycastle.asn1. You can use version before 146 (including 146) to resolve this question.

It's strange that the jars available at bouncycastle.org don't seem to contain this class. Perhaps, you may want to use one from the locations listed in this page (link).

i have the same problem, but a fix it when i download the libreria and update those files on /WEBINF/LIB

Luckily, the dependency jars are being delivered along with the iText now.
Please check the repository link below and download extrajars.zip file
http://sourceforge.net/projects/itext/files/

For jruby-ers with the same failure, I updated to jruby-complete-9.1.13.0.jar from jruby-complete-1.6.6.jar and the problem seemed to resolve...FWIW...

Android: error including/repacking dependencies which reference javax core classes

I'm working on an Android app using Maven as the build tool. I managed to set evertyhing up correctly (maven dependencies are exported to the apk etc.), however I have one remaining problem which is driving me crazy.
I want to include a dependency on simpleframework's xml parser defined as follows in my POM file:
<dependency>
<groupId>org.simpleframework</groupId>
<artifactId>simple-xml</artifactId>
<version>2.5.3</version>
</dependency>
When I issue mvn install on the project, I get the following error (truncated):
trouble processing "javax/xml/namespace/NameSpaceContext.class" ...
I know the error results from the simple xml parser referencing these javax-classes, however I haven't found a solution yet (setting the --core-library flag is of no use).
I'm currently trying to repack the dependency with the maven-jarjar-pluging but this doesn't seem to work either.
Can anyone help me out with this? Many, many thanks in advance!

Define your simple-xml depedency like this :
<dependency>
<groupId>org.simpleframework</groupId>
<artifactId>simple-xml</artifactId>
<version>2.6.1</version>
<exclusions>
<!-- StAX is not available on Android -->
<exclusion>
<artifactId>stax</artifactId>
<groupId>stax</groupId>
</exclusion>
<exclusion>
<artifactId>stax-api</artifactId>
<groupId>stax</groupId>
</exclusion>
<!-- Provided by Android -->
<exclusion>
<artifactId>xpp3</artifactId>
<groupId>xpp3</groupId>
</exclusion>
</exclusions>
</dependency>

I use android-maven-plugin, and adding <coreLibrary>true</coreLibrary> to the <configuration> tag of the plugin in the POM works for me. However, there's a bug: https://github.com/jayway/maven-android-plugin/pull/34, that you need to include to fix the plugin you are using, since the bug won't be fixed until 3.0. Here's how I got it working for me using 2.9.0-SNAPSHOT.
add a pluginRepository pointing to http:// oss.sonatype.org/content/repositories/jayway-snapshots/ to get 2.9.0-SNAPSHOT
update your plugin version to use 2.9.0-SNAPSHOT and add <coreLibrary>true</coreLibrary> to pom.xml
get the fix: git clone https://github.com/kevinpotgieter/maven-android-plugin.git
remove src/test/java/com: so the test won't fail
mvn package
copy it and overwrite your local maven cache in .m2 (You may need to remove your plugin repository yours gets overwritten every time.)
Step 3-6 won't be necessary after the fix gets into 2.9.0-SNAPSHOT.
Update July 2010: 2.9.0-beta-4 has the fix, so you don't need the above workaround if you use 2.9.0-beta-4 or later. I tested 2.9.0-beta-5 which worked just fine.

Spring Android uses Maven to integrate Simple. Take a look at the following URL, it should provide pointers on how to get Maven working with Simple.
http://static.springsource.org/spring-android/docs/1.0.x/reference/html/rest-template.html