I've seen answers to questions similar to mine, but I've tried everything, the error doesn't go away. I understand that the api servlet classes are loaded by two different class loaders because there are multiple sources in the web deployment assembly. I tried to remove that with servlet-api-3.0-alpha-1.jar, but if I remove the same package from WEB-INF\lib folder, it gives me more errors. There is also to add that it is a spring project imported into eclipse, I had created a web dynamic project which I then converted into a maven project. Since by debugging, I discovered that the embedded server was not running the updated jsp pages for me, I changed the project to mvc so as to have the normal server in eclipse. The server is tomcat 10, I can't figure out which packages it loads from maven and which ones from the lib folder.
if I delete from lib servlet-api-3.0-alpha-1.jar, the error appears to me: The type javax.servlet.ServletContext cannot be resolved. It is indirectly referenced from required .class files MyInitializer.java
If I delete from lib jakarta.el-5.0-M1.jar, the error appears to me: The project cannot be built until build path errors are resolved
Project 'Parlamento' is missing required library: 'C:\Users\segreteria\Desktop\WORKSPACE 4\Parlamento\src\main\webapp\WEB-INF\lib\jakarta.el-5.0.0-M1.jar'
if I downgrade tomcat from 10 to 9, i have to change also the spring version because tomcat 9 doesn't support version 5, and then i have to change all the jar packages.
if i use tomcat 9.0.62 then i have to use spring 4 so i have to use applicationContext.xml which throws other errors which is fixed in later versions of tomcat and this brings me back to update spring packages again.
STACKTRACE:
SEVERE: Allocate exception for servlet [Parlamento]
java.lang.ClassCastException: class org.springframework.web.servlet.DispatcherServlet
cannot be cast to class jakarta.servlet.Servlet
(org.springframework.web.servlet.DispatcherServlet is in unnamed module of loader
org.apache.catalina.loader.ParallelWebappClassLoader @1601e47;
jakarta.servlet.Servlet is in unnamed module of loader java.net.URLClassLoader
@6bdf28bb)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1071)
at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:789)
at
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:128)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97)
at
org.apache.catalina.authenticator.AuthenticatorBase.invoke(
AuthenticatorBase.java:542)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:119)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at
org.apache.catalina.valves.AbstractAccessLogValve.invoke
(AbstractAccessLogValve.java:690)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:356)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process
(AbstractProtocol.java:867)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun
(NioEndpoint.java:1762)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker
(ThreadPoolExecutor.java:1191)
at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run
(ThreadPoolExecutor.java:659)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.base/java.lang.Thread.run(Thread.java:833)
pom.xml
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.7.5</version>
<relativePath></relativePath>
</parent>
<groupId>com.giuggiola</groupId>
<artifactId>Parlamento</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<name>Parlamento</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>18</java.version>
</properties>
<dependencies>
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>org.apache.tomcat</groupId>
<artifactId>tomcat-annotations-api</artifactId>
<!-- <version>10.0.23</version>-->
</dependency>
<dependency>
<groupId>jakarta.servlet.jsp.jstl</groupId>
<artifactId>jakarta.servlet.jsp.jstl-api</artifactId>
<!-- <version>2.0.0</version> -->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<!-- <version>1.2</version> -->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-core</artifactId>
<version>6.1.5.Final</version>
<type>pom</type>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<!-- <version>6.0.0</version> -->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<!-- <version>4.13.2</version>-->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<!-- <version>5.3.23</version> -->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>jakarta.servlet</groupId>
<artifactId>jakarta.servlet-api</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>jakarta.servlet.jsp</groupId>
<artifactId>jakarta.servlet.jsp-api</artifactId>
<version>3.0.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>jakarta.el</groupId>
<artifactId>jakarta.el-api</artifactId>
<version>4.0.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>jakarta.websocket</groupId>
<artifactId>jakarta.websocket-api</artifactId>
<!-- <version>2.0.0</version> -->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>jakarta.security.enterprise</groupId>
<artifactId>jakarta.security.enterprise-api</artifactId>
<version>2.0.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.postgresql</groupId>
<artifactId>postgresql</artifactId>
<!-- <version>42.5.0</version> -->
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
<!-- <version>2.7.3</version>-->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-autoconfigure</artifactId>
<!-- <version>2.7.4</version>-->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot</artifactId>
<!-- <version>2.7.4</version>-->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.vladmihalcea</groupId>
<artifactId>hibernate-types-55</artifactId>
<version>2.14.0</version>
</dependency>
</dependencies>
<build>
<finalName>Parlamento</finalName>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
<!-- plugin che ho aggiunto io-->
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<!-- <version>3.2.0</version> -->
<!-- <scope>provided</scope> -->
</plugin>
</plugins>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
</project>
lib
STACKTRACE:
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Server version name: Apache Tomcat/9.0.69
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Server built: Nov 9 2022 18:43:47 UTC
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Server version number: 9.0.69.0
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Name: Windows 8
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: OS Version: 6.2
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Architecture: amd64
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Java Home: C:\Program Files\Java\jdk-
17.0.5_windows-x64_bin\jdk-17.0.5
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Version: 17.0.5 9-LTS-191
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: JVM Vendor: Oracle Corporation
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_BASE:
C:\Users\segreteria\Desktop\WORKSPACE
4\.metadata\.plugins\org.eclipse.wst.server.core\tmp1
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: CATALINA_HOME: C:\Program Files\Apache Software
Foundation\Tomcat 9.0_Tomcat9.0.69
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -
XX: ShowCodeDetailsInExceptionMessages
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -
agentlib:jdwp=transport=dt_socket,suspend=y,address=
localhost:65348
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -
javaagent:C:\Users\segreteria\eclipse\jee-2022-
06\eclipse\configuration\org.eclipse.osgi\407\0\.cp\lib\
javaagent-shaded.jar
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -
Dcatalina.base=C:\Users\segreteria\Desktop\WORKSPACE
4\.metadata\.plugins\org.eclipse.wst.server.core\tmp1
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dcatalina.home=C:\Program
Files\Apache Software Foundation\Tomcat 9.0_Tomcat9.0.69
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -
.deploy=C:\Users\segreteria\Desktop\WORKSPACE
4\.metadata\.plugins\org.eclipse.wst.server.core\tmp1\wtpwebapps
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: --add-opens=java.base/java.lang=ALL-
UNNAMED
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: --add-opens=java.base/java.io=ALL-
UNNAMED
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: --add-opens=java.base/java.util=ALL-
UNNAMED
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: --add-
opens=java.base/java.util.concurrent=ALL-UNNAMED
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: --add-
opens=java.rmi/sun.rmi.transport=ALL-UNNAMED
dic 06, 2022 6:13:12 PM
org.apache.catalina.startup.VersionLoggerListener log
INFO: Command line argument: -Dfile.encoding=UTF-8
dic 06, 2022 6:13:13 PM
org.apache.catalina.core.AprLifecycleListener lifecycleEvent
INFO: The Apache Tomcat Native library which allows using OpenSSL
was not found on the java.library.path: [C:\Program
Files\Java\jdk-17.0.5_windows-x64_bin\jdk-
17.0.5\bin;C:\Windows\Sun\Java\bin;C:\Windows\system32;C:
Windows;C:\Program Files\Common
Files\Oracle\Java\javapath;C:\Program Files (x86)\Common
Files\Oracle\Java\javapath;C:\Windows\system32;C:\Windows;
C:\Windows\System32\Wbem;C:\Windows\System32\
WindowsPowerShell\v1.0\;C:\Maven\apache-maven-3.8.6-
bin\bin;C:\Program Files\Java\jdk-17.0.5_windows-x64_bin\jdk-
17.0.5\bin;;C:\Users\segreteria\AppData\Local\Programs\Microsoft
VS Code\bin;C:\Program Files\Java\jdk-17.0.5_windows-x64_bin\jdk-
17.0.5\bin;.]
dic 06, 2022 6:13:14 PM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-nio-8088"]
dic 06, 2022 6:13:15 PM org.apache.catalina.startup.Catalina load
INFO: Server initialization in [5346] milliseconds
dic 06, 2022 6:13:15 PM org.apache.catalina.core.StandardService
startInternal
INFO: Starting service [Catalina]
dic 06, 2022 6:13:15 PM org.apache.catalina.core.StandardEngine
startInternal
INFO: Starting Servlet engine: [Apache Tomcat/9.0.69]
dic 06, 2022 6:13:18 PM org.apache.jasper.servlet.TldScanner
scanJars
INFO: At least one JAR was scanned for TLDs yet contained no
TLDs. Enable debug logging for this logger for a complete list of
JARs that were scanned but no TLDs were found in them. Skipping
unneeded JARs during scanning can improve startup time and JSP
compilation time.
dic 06, 2022 6:13:18 PM
org.apache.catalina.util.SessionIdGeneratorBase
createSecureRandom
WARNING: Creation of SecureRandom instance for session ID
generation using [SHA1PRNG] took [122] milliseconds.
dic 06, 2022 6:13:26 PM org.apache.jasper.servlet.TldScanner
scanJars
INFO: At least one JAR was scanned for TLDs yet contained no
TLDs. Enable debug logging for this logger for a complete list of
JARs that were scanned but no TLDs were found in them. Skipping
unneeded JARs during scanning can improve startup time and JSP
compilation time.
CodePudding user response：
Spring 5 doesn't support Tomcat 10 but it runs perfectly fine on Tomcat 9.
In fact I just tested it by creating a simple project with your slightly fixed POM and running it on Tomcat 9.0.69.
Here's the POM:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.7.6</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>tomcat-demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<name>tomcat-demo</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>17</java.version>
</properties>
<dependencies>
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>org.apache.tomcat</groupId>
<artifactId>tomcat-annotations-api</artifactId>
<!-- <version>10.0.23</version>-->
</dependency>
<dependency>
<groupId>javax.servlet.jsp.jstl</groupId>
<artifactId>jstl-api</artifactId>
<version>1.2</version>
<!-- <version>2.0.0</version> -->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
<!-- <version>1.2</version> -->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.hibernate.orm</groupId>
<artifactId>hibernate-core</artifactId>
<version>6.1.5.Final</version>
<type>pom</type>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<!-- <version>6.0.0</version> -->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<!-- <version>4.13.2</version>-->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<!-- <version>5.3.23</version> -->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>jsp-api</artifactId>
<version>2.2</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.el</groupId>
<artifactId>el-api</artifactId>
<version>2.2</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.websocket</groupId>
<artifactId>javax.websocket-api</artifactId>
<!-- <version>2.0.0</version> -->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.security.enterprise</groupId>
<artifactId>javax.security.enterprise-api</artifactId>
<version>1.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.postgresql</groupId>
<artifactId>postgresql</artifactId>
<!-- <version>42.5.0</version> -->
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
<!-- <version>2.7.3</version>-->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-autoconfigure</artifactId>
<!-- <version>2.7.4</version>-->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot</artifactId>
<!-- <version>2.7.4</version>-->
<scope>provided</scope>
</dependency>
<dependency>
<groupId>com.vladmihalcea</groupId>
<artifactId>hibernate-types-55</artifactId>
<version>2.14.0</version>
</dependency>
</dependencies>
<build>
<finalName>${project.artifactId}</finalName>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<excludes>
<exclude>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</exclude>
</excludes>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<!-- <version>3.2.0</version> -->
<!-- <scope>provided</scope> -->
</plugin>
</plugins>
<resources>
<resource>
<directory>src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
</project>
Another thing to note is that there must be an implementation of SpringBootServletInitializer in your project to initialize the Servlet context required by Tomcat.
You can either make your @SpringBootApplication (or any @Configuration) extend SpringBootServletInitializer or make it a separate class:
public class ServletInitializer extends SpringBootServletInitializer {
@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
return application.sources(YourSpringBootApplication.class);
}
}