Content
Table of Contents
General
Please read general Migration Guide page first, for common considerations that apply to migration or upgrade between versions of Apache Tomcat.
Migrating from 9.0.x to 10.0.x
This section lists all the known changes between 9.0.x and 10.0.x which may cause backwards compatibility problems when upgrading.
Java 8 required
Apache Tomcat 10.0.x requires Java 8 or later. This is unchanged from Tomcat 9.0.x.
Specification APIs
Apache Tomcat 10 supports the Jakarta Servlet 5.0, Jakarta Server Pages 3.0, Jakarta Expression Language 4.0, JakartaWebSocket 2.0 and Jakarta Authentication 2.0 specifications.
There is a significant breaking change between Tomcat 9.0.x and Tomcat
10.0.x. The Java package used by the specification APIs has changed from
Tomcat can convert an existing web application from Java EE 8
to Jakarta EE 9 at deployment time using the Apache Tomcat migration tool
for Jakarta EE. To make use of the feature, the web application should
be placed in the Host legacyAppBase folder (by default named
webapps-javaee) and they will be converted to an equivalent
Jakarta EE web application in the Host appBase folder (by
default named webapps).
Alternately, the Apache Tomcat migration tool for Jakarta EE or any similar conversion tool can be used ahead of time to benefit from faster deployment time and more precise conversion configuration options.
Servlet 5.0 API
The Java package has changed from
Server Pages 3.0
The Java package has changed from
Expression Language 4.0
The Java package has changed from
WebSocket 2.0
The Java package has changed from
Authentication 4.0
The Java package has changed from
Internal APIs
Whilst the Tomcat 10 internal API is broadly compatible with Tomcat 9 there have been many changes at the detail level and they are not binary compatible. Developers of custom components that interact with Tomcat's internals should review the JavaDoc for the relevant API.
Of particular note are:
GenericPrincipal.getPassword() has been removed.
web.xml defaults
conf/web.xml sets the default request and response character
encoding to UTF-8.
Session management
Session persistence on restart has been disabled by default. It may be
re-enabled globally in
HTTP/2
The configuration settings that were duplicated between the HTTP/1.1 and HTTP/2 connectors have been removed from the HTTP/2 connector which will now inherit them from the associated HTTP/1.1 connector.
Logging
The logging implementation now only creates log files once there is something to write to the log files.
Upgrading 10.0.x
When upgrading instances of Apache Tomcat from one version of Tomcat 10 to another, particularly when using separate locations for $CATALINA_HOME and $CATALINA_BASE, it is necessary to ensure that any changes in the configuration files such as new attributes and changes to defaults are applied as part of the upgrade. To assist with the identification of these changes, the form below may be used to view the differences between the configuration files in different versions of Tomcat 10.
Tomcat 10.0.x noteable changes
The Tomcat developers aim for each patch release to be fully backwards compatible with the previous release. Occasionally, it is necessary to break backwards compatibility in order to fix a bug. In most cases, these changes will go unnoticed. This section lists changes that are not fully backwards compatible and might cause breakage when upgrading.
None as yet.
Tomcat 10.0.x configuration file differences
Select a configuration file, old version and new version from the boxes below and then click "View differences" to see the differences. The differences will be shown in a new tab/window.
Note: If there are no differences you will see an error page.
You can also use a Git command similar to the following from within a working copy:
git diff 10.0.0 10.0.12 -- conf/