Support stable EA builds (#83)

Support stable EA builds by adding a new `ea,stable,...` aliases.

Author: sormuras

CHANGELOG.md

@@ -6,6 +6,9 @@ This project uses tags and branches for [release management](https://docs.github
 
 
 ## [Unreleased]
+### Added
+- Java `23` and `24` to the list of Early-Access releases
+- New `version: stable` mode for `release: ea` setups
 
 ## [1.3.4] - 2024-03-21
 ### Fixed

README.md

@@ -50,10 +50,9 @@ It is set by default to `latest`.
 
 ___
 
-**WARNING!**
-
-Older versions of the JDK are provided to help developers debug issues in older systems.
-**They are not updated with the latest security patches and are not recommended for use in production.**
+> [!CAUTION]
+> Older versions of the JDK are provided to help developers debug issues in older systems.
+> **They are not updated with the latest security patches and are not recommended for use in production.**
 
 ___
 
@@ -111,10 +110,9 @@ steps:
 ```
 ___
 
-**WARNING!**
-
-Older versions of the JDK are provided to help developers debug issues in older systems.
-**They are not updated with the latest security patches and are not recommended for use in production.**
+> [!CAUTION]
+> Older versions of the JDK are provided to help developers debug issues in older systems.
+> **They are not updated with the latest security patches and are not recommended for use in production.**
 
 ___
 
@@ -133,6 +131,11 @@ steps:
       release: N # Replace N with GA, EA, 17, 18, 19, ...
 ```
 
+> [!NOTE]
+> This action supports two `version` update early-access modes for `release: EA` on `jdk.java.net`:
+>   - `version: latest` updates as early as possible to the latest-and-greatest JDK build (default)
+>   - `version: stable` updates later in the release cycle, usually then a new JDK build goes GA
+
 ### Download and install an Early-Access build of a named OpenJDK project
 
 ```yaml

src/ListOpenJavaDevelopmentKits.java

@@ -9,6 +9,7 @@
 import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
 import java.net.http.HttpResponse;
+import java.util.ArrayList;
 import java.util.List;
 import java.util.StringJoiner;
 import java.util.TreeMap;
@@ -31,7 +32,7 @@
  *
  * <ul>
  *   <li>{@code RELEASE}: Either a release number or a name of an early-access project
- *   <li>{@code VERSION}: Either a specific version or `latest`
+ *   <li>{@code VERSION}: Either a specific version or `latest` or `stable`
  *   <li>{@code OS-NAME}: An operating system name, usually one of: `linux`, `macos`, `windows`
  *   <li>{@code OS-ARCH}: An operating system architecture, like: `aarch64`, `x64`, or `x64-musl`
  * </ul>
@@ -47,6 +48,12 @@ class ListOpenJavaDevelopmentKits {
   /** Early-Access Releases, as comma separated names. */
   static final String EA = System.getProperty("EA", "24,23,jextract,loom,valhalla");
 
+  /** Current "latest" Early-Access Release number. */
+  static final String EA_LATEST = System.getProperty("EA_LATEST", "24");
+
+  /** Current "stable" Early-Access Release number. */
+  static final String EA_STABLE = System.getProperty("EA_STABLE", "23");
+
   /** Include archived releases flag. */
   static final boolean ARCHIVES = Boolean.getBoolean("ARCHIVES");
 
@@ -137,12 +144,25 @@ static List<String> generateEarlyAccessAliasKeys(String[] components) {
       var from = version.indexOf('-');
       var till = version.indexOf('+');
       var project = from >= 0 && from < till ? version.substring(from + 1, till) : version;
-      components[0] = project;
+      if (project.equals("ea")) {
+        var earlyAccessAliases = new ArrayList<String>();
+        components[0] = release; // "23", "24", ...
+        components[1] = "latest";
+        earlyAccessAliases.add(String.join(",", components));
+        components[0] = "ea";
+        if (release.equals(EA_LATEST)) {
+          components[1] = "latest";
+          earlyAccessAliases.add(String.join(",", components));
+        }
+        if (release.equals(EA_STABLE)) {
+          components[1] = "stable";
+          earlyAccessAliases.add(String.join(",", components));
+        }
+        return earlyAccessAliases;
+      }
+      components[0] = project; // "loom", "valhalla", ...
       components[1] = "latest";
-      var alias = String.join(",", components);
-      if (!project.equals("ea")) return List.of(alias);
-      components[0] = release; // 18-latest-...
-      return List.of(alias, String.join(",", components));
+      return List.of(String.join(",", components));
     } catch (IndexOutOfBoundsException exception) {
       System.err.println("Early-Access version without `-` and `+`: " + version);
       return List.of();