ICU-22534 Script preparing the GitHub icu4j release files

See #2665

docs/processes/release/tasks/versions.md

@@ -213,6 +213,7 @@ Edit the root pom file at `icu4j/pom.xml` and manually make this change:
 5. Update the following variables in `icu4j/releases_tools/shared.sh`
 
     * `artifact_version` - The version used in the Maven `pom.xml` files. You can alternatively produce this value by running `mvn help:evaluate -Dexpression=project.version -q -DforceStdout`.
+    * `github_rel_version` - The version used in the name of the GitHub downloadable artifacts. For example "73_2" or "74rc".
     * `api_report_version` - The major version of the new version. Change during RC BRS.
     * `api_report_prev_version`  - The major version of the previous version. Change during RC BRS.
 

icu4j/releases_tools/api_reports.sh

@@ -8,20 +8,6 @@ if [ ! -f "releases_tools/shared.sh" ]; then
 fi
 . releases_tools/shared.sh
 
-function checkThatJdk8IsDefault() {
-  javac -version appPath 2>&1 | grep -E 'javac 1\.8\.' > /dev/null
-  if [ $? -eq 0 ]; then
-    echo "The default JDK version is 8, all good!"
-    javac -version
-  else
-    echo "This step can only be executed with JDK 8!"
-    echo "Make sure that you have the PATH pointing to a JDK 8!"
-    javac -version
-    exit
-  fi
-
-}
-
 # ====================================================================================
 # The start of the script proper
 

icu4j/releases_tools/github_release.sh

@@ -0,0 +1,56 @@
+#!/usr/bin/env bash
+# Copyright (C) 2023 and later: Unicode, Inc. and others.
+# License & terms of use: http://www.unicode.org/copyright.html
+
+if [ ! -f "releases_tools/shared.sh" ]; then
+  echo "ERROR: This script should be executed while being in the icu4j folder"
+  exit
+fi
+. releases_tools/shared.sh
+
+function copyArtifactForGithubRelease() {
+  local artifactId=$1
+  # Copy artifacts in the output folder
+  mvn dependency:copy -q -Dmdep.stripVersion=true -Dartifact=com.ibm.icu:${artifactId}:${artifact_version} -DoutputDirectory=${release_folder}
+  mvn dependency:copy -q -Dmdep.stripVersion=true -Dartifact=com.ibm.icu:${artifactId}:${artifact_version}:jar:sources -DoutputDirectory=${release_folder}
+  # Change the names
+  mv ${release_folder}/${artifactId}.jar ${release_folder}/${artifactId}-${github_rel_version}.jar
+  mv ${release_folder}/${artifactId}-sources.jar ${release_folder}/${artifactId}-${github_rel_version}-sources.jar
+}
+
+# ====================================================================================
+# The start of the script proper
+
+release_folder=${out_dir}/github_release
+# We still need JDK 8 to generate the javadoc (because of the doclets)
+checkThatJdk8IsDefault
+
+# ====================================================================================
+# Build artifacts and copy them in the output folder
+
+reportTitle Prepare folder with artifacts for GitHub release
+
+mvn clean install -DskipITs -DskipTests -P with_sources
+
+rm   -fr ${release_folder}
+mkdir -p ${release_folder}
+copyArtifactForGithubRelease icu4j
+copyArtifactForGithubRelease icu4j-charset
+copyArtifactForGithubRelease icu4j-localespi
+
+# ====================================================================================
+# Build complete javadoc and copy it in the output folder
+
+reportTitle Prepare complete javadoc for GitHub release
+
+mvn site -DskipITs -DskipTests -P with_full_javadoc
+
+jar -Mcf ${release_folder}/icu4j-${github_rel_version}-javadoc.jar  -C ${out_dir}/site/apidocs/ .
+
+# ====================================================================================
+
+pushd ${release_folder}
+md5sum *.jar > icu4j-${github_rel_version}.md5
+popd
+
+reportTitle "You can find the results in ${release_folder}/"

icu4j/releases_tools/shared.sh

@@ -6,6 +6,7 @@ export MAVEN_ARGS='--no-transfer-progress'
 
 # Version update!
 export artifact_version='74.1-SNAPSHOT'
+export github_rel_version='74rc'
 export api_report_version='74'
 export api_report_prev_version='73'
 export out_dir=target