Extract recurring asciidoc links to attributes, cleanup old doc files

This commit extract spring-related links and recurring external links
into asciidoctor attributes to be used by the Antora toolchain.

It notably homogenizes links to:
 - IETF RFCs
 - Java Community Process JSRs
 - the Java API Documentation (on the Java 17 version)
 - Kotlin documentations (on the Kotlinlang.org version)
 - the Spring Boot reference guide (on the `html` version)

This commit also reworks most link attributes to follow a
Project-Category-Misc syntax. For example, `spring-boot-docs` rather
than `docs-spring-boot`.

Finally, it makes an effort to clean up remainders from the previous
documentation toolchain, namely the `docs/asciidoc` folder and 
`modules/ROOT/pages/attributes.adoc` file.

Closes gh-26864
Closes gh-31619

framework-docs/antora.yml

@@ -17,16 +17,73 @@ asciidoc:
     # FIXME: the copyright is not removed
     # FIXME: The package is not renamed
     chomp: 'all'
+    fold: 'all'
     include-java: 'example$docs-src/main/java/org/springframework/docs'
-    spring-framework-main-code: 'https://github.com/spring-projects/spring-framework/tree/main'
+    spring-site: 'https://spring.io'
+    spring-site-blog: '{spring-site}/blog'
+    spring-site-cve: "{spring-site}/security"
+    spring-site-guides: '{spring-site}/guides'
+    spring-site-projects: '{spring-site}/projects'
+    spring-site-tools: "{spring-site}/tools"
+    spring-org: 'spring-projects'
+    spring-github-org: "https://github.com/{spring-org}"
+    spring-framework-github: "https://github.com/{spring-org}/spring-framework"
+    spring-framework-code: '{spring-framework-github}/tree/main'
+    spring-framework-issues: '{spring-framework-github}/issues'
+    spring-framework-wiki: '{spring-framework-github}/wiki'
+    # Docs
     docs-site: 'https://docs.spring.io'
-    docs-spring: "{docs-site}/spring-framework/docs/{spring-version}"
-    docs-spring-framework: '{docs-site}/spring-framework/docs/{spring-version}'
-    api-spring-framework: '{docs-spring-framework}/javadoc-api/org/springframework'
-    docs-graalvm: 'https://www.graalvm.org/22.3/reference-manual'
-    docs-spring-boot: '{docs-site}/spring-boot/docs/current/reference'
+    spring-framework-docs-root: '{docs-site}/spring-framework/docs'
+    spring-framework-api: '{spring-framework-docs-root}/{spring-version}/javadoc-api/org/springframework'
+    spring-framework-api-kdoc: '{spring-framework-docs-root}/{spring-version}/kdoc-api'
+    spring-framework-reference: '{spring-framework-docs-root}/{spring-version}/reference'
+    #
+    # Other Spring portfolio projects
+    spring-boot-docs: '{docs-site}/spring-boot/docs/current/reference/html'
+    spring-boot-issues: '{spring-github-org}/spring-boot/issues'
+    # TODO add more projects / links or just build up on {docs-site}?
+    # TODO rename the below using new conventions
     docs-spring-gemfire: '{docs-site}/spring-gemfire/docs/current/reference'
     docs-spring-security: '{docs-site}/spring-security/reference'
-    gh-rsocket: 'https://github.com/rsocket'
-    gh-rsocket-extensions: '{gh-rsocket}/rsocket/blob/master/Extensions'
-    gh-rsocket-java: '{gh-rsocket}/rsocket-java{gh-rsocket}/rsocket-java'
+    docs-spring-session: '{docs-site}/spring-session/reference'
+    #
+    # External projects URLs and related attributes
+    aspectj-site: 'https://www.eclipse.org/aspectj'
+    aspectj-docs: "{aspectj-site}/doc/released"
+    aspectj-api: "{aspectj-docs}/runtime-api"
+    aspectj-docs-devguide: "{aspectj-docs}/devguide"
+    aspectj-docs-progguide: "{aspectj-docs}/progguide"
+    assertj-docs: 'https://assertj.github.io/doc'
+    baeldung-blog: 'https://www.baeldung.com'
+    bean-validation-site: 'https://beanvalidation.org'
+    graalvm-docs: 'https://www.graalvm.org/22.3/reference-manual'
+    hibernate-validator-site: 'https://hibernate.org/validator/'
+    jackson-docs: 'https://fasterxml.github.io'
+    jackson-github-org: 'https://github.com/FasterXML'
+    java-api: 'https://docs.oracle.com/en/java/javase/17/docs/api'
+    java-tutorial: 'https://docs.oracle.com/javase/tutorial'
+    JSR: 'https://www.jcp.org/en/jsr/detail?id='
+    kotlin-site: 'https://kotlinlang.org'
+    kotlin-docs: '{kotlin-site}/docs'
+    kotlin-api: '{kotlin-site}/api/latest'
+    kotlin-coroutines-api: '{kotlin-site}/api/kotlinx.coroutines'
+    kotlin-github-org: 'https://github.com/Kotlin'
+    kotlin-issues: 'https://youtrack.jetbrains.com/issue'
+    reactive-streams-site: 'https://www.reactive-streams.org'
+    reactive-streams-spec: 'https://github.com/reactive-streams/reactive-streams-jvm/blob/master/README.md#specification'
+    reactor-github-org: 'https://github.com/reactor'
+    reactor-site: 'https://projectreactor.io'
+    rsocket-github-org: 'https://github.com/rsocket'
+    rsocket-java: '{rsocket-github-org}/rsocket-java'
+    rsocket-java-code: '{rsocket-java}/tree/master/'
+    rsocket-protocol-extensions: '{rsocket-github-org}/rsocket/tree/master/Extensions'
+    rsocket-site: 'https://rsocket.io'
+    rfc-site: 'https://datatracker.ietf.org/doc/html'
+    sockjs-client: 'https://github.com/sockjs/sockjs-client'
+    sockjs-protocol: 'https://github.com/sockjs/sockjs-protocol'
+    sockjs-protocol-site: "https://sockjs.github.io/sockjs-protocol"
+    stackoverflow-site: 'https://stackoverflow.com'
+    stackoverflow-questions: '{stackoverflow-site}/questions'
+    stackoverflow-spring-tag: "{stackoverflow-questions}/tagged/spring"
+    stackoverflow-spring-kotlin-tags: "{stackoverflow-spring-tag}+kotlin"
+    testcontainers-site: 'https://www.testcontainers.org'

framework-docs/modules/ROOT/nav.adoc

@@ -439,4 +439,4 @@
 ** xref:languages/groovy.adoc[]
 ** xref:languages/dynamic.adoc[]
 * xref:appendix.adoc[]
-* https://github.com/spring-projects/spring-framework/wiki[Wiki]
+* {spring-framework-wiki}[Wiki]

framework-docs/modules/ROOT/pages/appendix.adoc

@@ -8,7 +8,7 @@ within the core Spring Framework.
 [[appendix-spring-properties]]
 == Spring Properties
 
-{api-spring-framework}/core/SpringProperties.html[`SpringProperties`] is a static holder
+{spring-framework-api}/core/SpringProperties.html[`SpringProperties`] is a static holder
 for properties that control certain low-level aspects of the Spring Framework. Users can
 configure these properties via JVM system properties or programmatically via the
 `SpringProperties.setProperty(String key, String value)` method. The latter may be
@@ -25,7 +25,7 @@ The following table lists all currently supported Spring properties.
 | `spring.beaninfo.ignore`
 | Instructs Spring to use the `Introspector.IGNORE_ALL_BEANINFO` mode when calling the
 JavaBeans `Introspector`. See
-{api-spring-framework}++/beans/StandardBeanInfoFactory.html#IGNORE_BEANINFO_PROPERTY_NAME++[`CachedIntrospectionResults`]
+{spring-framework-api}++/beans/StandardBeanInfoFactory.html#IGNORE_BEANINFO_PROPERTY_NAME++[`CachedIntrospectionResults`]
 for details.
 
 | `spring.expression.compiler.mode`
@@ -36,7 +36,7 @@ xref:core/expressions/evaluation.adoc#expressions-compiler-configuration[Spring
 | Instructs Spring to ignore operating system environment variables if a Spring
 `Environment` property -- for example, a placeholder in a configuration String -- isn't
 resolvable otherwise. See
-{api-spring-framework}++/core/env/AbstractEnvironment.html#IGNORE_GETENV_PROPERTY_NAME++[`AbstractEnvironment`]
+{spring-framework-api}++/core/env/AbstractEnvironment.html#IGNORE_GETENV_PROPERTY_NAME++[`AbstractEnvironment`]
 for details.
 
 | `spring.jdbc.getParameterType.ignore`
@@ -47,12 +47,12 @@ See the note in xref:data-access/jdbc/advanced.adoc#jdbc-batch-list[Batch Operat
 | Instructs Spring to ignore a default JNDI environment, as an optimization for scenarios
 where nothing is ever to be found for such JNDI fallback searches to begin with, avoiding
 the repeated JNDI lookup overhead. See
-{api-spring-framework}++/jndi/JndiLocatorDelegate.html#IGNORE_JNDI_PROPERTY_NAME++[`JndiLocatorDelegate`]
+{spring-framework-api}++/jndi/JndiLocatorDelegate.html#IGNORE_JNDI_PROPERTY_NAME++[`JndiLocatorDelegate`]
 for details.
 
 | `spring.objenesis.ignore`
 | Instructs Spring to ignore Objenesis, not even attempting to use it. See
-{api-spring-framework}++/objenesis/SpringObjenesis.html#IGNORE_OBJENESIS_PROPERTY_NAME++[`SpringObjenesis`]
+{spring-framework-api}++/objenesis/SpringObjenesis.html#IGNORE_OBJENESIS_PROPERTY_NAME++[`SpringObjenesis`]
 for details.
 
 | `spring.test.aot.processing.failOnError`

framework-docs/modules/ROOT/pages/core/aop-api/extensibility.adoc

@@ -12,5 +12,5 @@ support for new custom advice types be added without changing the core framework
 The only constraint on a custom `Advice` type is that it must implement the
 `org.aopalliance.aop.Advice` marker interface.
 
-See the {api-spring-framework}/aop/framework/adapter/package-summary.html[`org.springframework.aop.framework.adapter`]
+See the {spring-framework-api}/aop/framework/adapter/package-summary.html[`org.springframework.aop.framework.adapter`]
 javadoc for further information.

framework-docs/modules/ROOT/pages/core/aop-api/targetsource.adoc

@@ -119,7 +119,7 @@ The following listing shows an example configuration:
 
 Note that the target object (`businessObjectTarget` in the preceding example) must be a
 prototype. This lets the `PoolingTargetSource` implementation create new instances
-of the target to grow the pool as necessary. See the {api-spring-framework}/aop/target/AbstractPoolingTargetSource.html[javadoc of
+of the target to grow the pool as necessary. See the {spring-framework-api}/aop/target/AbstractPoolingTargetSource.html[javadoc of
 `AbstractPoolingTargetSource`] and the concrete subclass you wish to use for information
 about its properties. `maxSize` is the most basic and is always guaranteed to be present.
 

framework-docs/modules/ROOT/pages/core/aop/aspectj-programmatic.adoc

@@ -52,7 +52,7 @@ Kotlin::
 ----
 ======
 
-See the {api-spring-framework}/aop/aspectj/annotation/AspectJProxyFactory.html[javadoc] for more information.
+See the {spring-framework-api}/aop/aspectj/annotation/AspectJProxyFactory.html[javadoc] for more information.
 
 
 

framework-docs/modules/ROOT/pages/core/aop/ataspectj.adoc

@@ -4,7 +4,7 @@
 
 @AspectJ refers to a style of declaring aspects as regular Java classes annotated with
 annotations. The @AspectJ style was introduced by the
-https://www.eclipse.org/aspectj[AspectJ project] as part of the AspectJ 5 release. Spring
+{aspectj-site}[AspectJ project] as part of the AspectJ 5 release. Spring
 interprets the same annotations as AspectJ 5, using a library supplied by AspectJ
 for pointcut parsing and matching. The AOP runtime is still pure Spring AOP, though, and
 there is no dependency on the AspectJ compiler or weaver.

framework-docs/modules/ROOT/pages/core/aop/ataspectj/advice.adoc

@@ -482,7 +482,7 @@ The `JoinPoint` interface provides a number of useful methods:
 * `getSignature()`: Returns a description of the method that is being advised.
 * `toString()`: Prints a useful description of the method being advised.
 
-See the https://www.eclipse.org/aspectj/doc/released/runtime-api/org/aspectj/lang/JoinPoint.html[javadoc] for more detail.
+See the {aspectj-api}/org/aspectj/lang/JoinPoint.html[javadoc] for more detail.
 
 [[aop-ataspectj-advice-params-passing]]
 === Passing Parameters to Advice
@@ -730,7 +730,7 @@ of determining parameter names, an exception will be thrown.
   flag for `javac`. Recommended approach on Java 8+.
 `AspectJAdviceParameterNameDiscoverer` :: Deduces parameter names from the pointcut
   expression, `returning`, and `throwing` clauses. See the
-  {api-spring-framework}/aop/aspectj/AspectJAdviceParameterNameDiscoverer.html[javadoc]
+  {spring-framework-api}/aop/aspectj/AspectJAdviceParameterNameDiscoverer.html[javadoc]
   for details on the algorithm used.
 
 [[aop-ataspectj-advice-params-names-explicit]]

framework-docs/modules/ROOT/pages/core/aop/ataspectj/pointcuts.adoc

@@ -36,9 +36,9 @@ Kotlin::
 
 The pointcut expression that forms the value of the `@Pointcut` annotation is a regular
 AspectJ pointcut expression. For a full discussion of AspectJ's pointcut language, see
-the https://www.eclipse.org/aspectj/doc/released/progguide/index.html[AspectJ
+the {aspectj-docs-progguide}/index.html[AspectJ
 Programming Guide] (and, for extensions, the
-https://www.eclipse.org/aspectj/doc/released/adk15notebook/index.html[AspectJ 5
+{aspectj-docs}/adk15notebook/index.html[AspectJ 5
 Developer's Notebook]) or one of the books on AspectJ (such as _Eclipse AspectJ_, by Colyer
 et al., or _AspectJ in Action_, by Ramnivas Laddad).
 
@@ -392,7 +392,7 @@ method that takes no parameters, whereas `(..)` matches any number (zero or more
 The `({asterisk})` pattern matches a method that takes one parameter of any type.
 `(*,String)` matches a method that takes two parameters. The first can be of any type, while the
 second must be a `String`. Consult the
-https://www.eclipse.org/aspectj/doc/released/progguide/semantics-pointcuts.html[Language
+{aspectj-docs-progguide}/semantics-pointcuts.html[Language
 Semantics] section of the AspectJ Programming Guide for more information.
 
 The following examples show some common pointcut expressions:

framework-docs/modules/ROOT/pages/core/aop/resources.adoc

@@ -2,7 +2,7 @@
 = Further Resources
 :page-section-summary-toc: 1
 
-More information on AspectJ can be found on the https://www.eclipse.org/aspectj[AspectJ website].
+More information on AspectJ can be found on the {aspectj-site}[AspectJ website].
 
 _Eclipse AspectJ_ by Adrian Colyer et. al. (Addison-Wesley, 2005) provides a
 comprehensive introduction and reference for the AspectJ language.

framework-docs/modules/ROOT/pages/core/aop/using-aspectj.adoc

@@ -136,7 +136,7 @@ using Spring in accordance with the properties of the annotation". In this conte
 "initialization" refers to newly instantiated objects (for example, objects instantiated
 with the `new` operator) as well as to `Serializable` objects that are undergoing
 deserialization (for example, through
-https://docs.oracle.com/javase/8/docs/api/java/io/Serializable.html[readResolve()]).
+{java-api}/java.base/java/io/Serializable.html[readResolve()]).
 
 [NOTE]
 =====
@@ -168,14 +168,13 @@ Kotlin::
 
 You can find more information about the language semantics of the various pointcut
 types in AspectJ
-https://www.eclipse.org/aspectj/doc/next/progguide/semantics-joinPoints.html[in this
-appendix] of the https://www.eclipse.org/aspectj/doc/next/progguide/index.html[AspectJ
-Programming Guide].
+{aspectj-docs-progguide}/semantics-joinPoints.html[in this appendix] of the
+{aspectj-docs-progguide}/index.html[AspectJ Programming Guide].
 =====
 
 For this to work, the annotated types must be woven with the AspectJ weaver. You can
 either use a build-time Ant or Maven task to do this (see, for example, the
-https://www.eclipse.org/aspectj/doc/released/devguide/antTasks.html[AspectJ Development
+{aspectj-docs-devguide}/antTasks.html[AspectJ Development
 Environment Guide]) or load-time weaving (see xref:core/aop/using-aspectj.adoc#aop-aj-ltw[Load-time Weaving with AspectJ in the Spring Framework]). The
 `AnnotationBeanConfigurerAspect` itself needs to be configured by Spring (in order to obtain
 a reference to the bean factory that is to be used to configure new objects). If you
@@ -399,7 +398,7 @@ The focus of this section is on configuring and using LTW in the specific contex
 Spring Framework. This section is not a general introduction to LTW. For full details on
 the specifics of LTW and configuring LTW with only AspectJ (with Spring not being
 involved at all), see the
-https://www.eclipse.org/aspectj/doc/released/devguide/ltw.html[LTW section of the AspectJ
+{aspectj-docs-devguide}/ltw.html[LTW section of the AspectJ
 Development Environment Guide].
 
 The value that the Spring Framework brings to AspectJ LTW is in enabling much
@@ -421,7 +420,7 @@ who typically are in charge of the deployment configuration, such as the launch
 Now that the sales pitch is over, let us first walk through a quick example of AspectJ
 LTW that uses Spring, followed by detailed specifics about elements introduced in the
 example. For a complete example, see the
-https://github.com/spring-projects/spring-petclinic[Petclinic sample application].
+{spring-github-org}/spring-petclinic[Petclinic sample application].
 
 
 [[aop-aj-ltw-first-example]]
@@ -621,7 +620,7 @@ java -javaagent:C:/projects/xyz/lib/spring-instrument.jar com.xyz.Main
 ----
 
 The `-javaagent` is a flag for specifying and enabling
-https://docs.oracle.com/javase/8/docs/api/java/lang/instrument/package-summary.html[agents
+{java-api}/java.instrument/java/lang/instrument/package-summary.html[agents
 to instrument programs that run on the JVM]. The Spring Framework ships with such an
 agent, the `InstrumentationSavingAgent`, which is packaged in the
 `spring-instrument.jar` that was supplied as the value of the `-javaagent` argument in
@@ -721,7 +720,7 @@ The AspectJ LTW infrastructure is configured by using one or more `META-INF/aop.
 files that are on the Java classpath (either directly or, more typically, in jar files).
 
 The structure and contents of this file is detailed in the LTW part of the
-https://www.eclipse.org/aspectj/doc/released/devguide/ltw-configuration.html[AspectJ reference
+{aspectj-docs-devguide}/ltw-configuration.html[AspectJ reference
 documentation]. Because the `aop.xml` file is 100% AspectJ, we do not describe it further here.