java.lang.NoClassDefFoundError : javax/xml/soap/SOAPException

JavaSE 8 includes package java.xml.soap.
JavaSE 9 moved package javax.xml.soap to the module java.xml.ws.
Modules shared with JEE (like java.xml.ws) are included in JavaSE 9, but are
- deprecated for removal from a future version of JavaSE, and
- not on the default module path.

A quick workaround is to either
- run the jar with JRE 8: $MY_JRE8_HOME/bin/java -jar my.jar, or
- add a module for JRE 9: java --add-modules java.xml.ws -jar my.jar

Longer term, JavaSE projects that use modules like java.xml.ws must explicitly include the module like other libraries.

See https://stackoverflow.com/a/46359097
See JDK 9 Migration Guide: Modules Shared with JEE Not Resolved by Default

(Reproduced NoClassDefError and workarounds with zipped SOAP web service project at https://spring.io/guides/gs/producing-web-service/)

Adding the following in pom file solved the issue

<!-- https://mvnrepository.com/artifact/javax.xml.soap/javax.xml.soap-api --><dependency>    <groupId>javax.xml.soap</groupId>    <artifactId>javax.xml.soap-api</artifactId>    <version>1.4.0</version></dependency>

Yes, In Java 11 java.xml.soap was completely removed.java.lang.NoClassDefFoundError: javax/xml/soap/SOAPException can be removed by adding the following dependency.

<dependency>    <groupId>jakarta.xml.soap</groupId>    <artifactId>jakarta.xml.soap-api</artifactId>    <version>2.0.0-RC3</version></dependency>

But later, you will encounter , javax.xml.soap.SOAPException: Unable to create SAAJ meta-factory: Provider com.sun.xml.internal.messaging.saaj.soap.SAAJMetaFactoryImpl not found.This can be solved by adding the following dependency.

<dependency>    <groupId>com.sun.xml.messaging.saaj</groupId>    <artifactId>saaj-impl</artifactId>    <version>1.5.1</version></dependency>

Hope, it helps!