feat: allow setting jdk default per version

Added a flag `--for-version` (or `-v`) to the `jdk default` command to
allow setting the default Jdk to use for a specific major version.
This is necessary now that we allow multiple Jdks of the same major
version to be installed simultaneously.

Author: quintesse

src/main/java/dev/jbang/cli/Jdk.java

@@ -306,6 +306,9 @@ public Integer exec(
 	@CommandLine.Command(name = "default", description = "Sets the default JDK to be used by JBang.")
 	public Integer defaultJdk(
 			@CommandLine.Parameters(paramLabel = "versionOrId", index = "0", description = "The version of the JDK to select", arity = "0..1") String versionOrId,
+			@CommandLine.Option(names = {
+					"--for-version",
+					"-v" }, description = "Sets the default for the specified major version") boolean forVersion,
 			@CommandLine.Option(names = {
 					"--show-details", "--details",
 					"-d" }, description = "Shows detailed information for each JDK (only when format=text)") boolean details,
@@ -316,11 +319,17 @@ public Integer defaultJdk(
 			Util.warnMsg("Cannot perform operation, the 'default' provider was not found");
 			return EXIT_INVALID_INPUT;
 		}
-		dev.jbang.devkitman.Jdk.InstalledJdk defjdk = jdkMan.getDefaultJdk();
 		if (versionOrId != null) {
 			dev.jbang.devkitman.Jdk.InstalledJdk jdk = jdkMan.getOrInstallJdk(versionOrId);
+			dev.jbang.devkitman.Jdk.InstalledJdk defjdk = forVersion
+					? jdkMan.getDefaultJdkForVersion(jdk.majorVersion())
+					: jdkMan.getDefaultJdk();
 			if (defjdk == null || (!jdk.equals(defjdk) && !Objects.equals(jdk.home(), defjdk.home()))) {
-				jdkMan.setDefaultJdk(jdk);
+				if (forVersion) {
+					jdkMan.setDefaultJdkForVersion(jdk);
+				} else {
+					jdkMan.setDefaultJdk(jdk);
+				}
 			} else {
 				Util.infoMsg("Default JDK already set to " + defjdk.majorVersion());
 			}

src/main/java/dev/jbang/util/JavaUtil.java

@@ -39,10 +39,10 @@ public static JdkManager defaultJdkManager(String... names) {
 	@NonNull
 	public static JdkManager defaultJdkManager(List<String> providers, List<String> vendors) {
 		return (new JdkManBuilder())
-                .provider(providers)
-                .vendor(vendors)
-                .defaultJavaVersion(Settings.getDefaultJavaVersion())
-                .build();
+			.provider(providers)
+			.vendor(vendors)
+			.defaultJavaVersion(Settings.getDefaultJavaVersion())
+			.build();
 	}
 
 	public static class JdkManBuilder extends JdkManager.Builder {

src/test/java/dev/jbang/cli/TestJdk.java

@@ -86,12 +86,12 @@ void testJdksAvailable() throws Exception {
 	void testDefault() throws Exception {
 		Arrays.asList(11, 12, 13).forEach(this::createMockJdk);
 
-		CaptureResult<Integer> result = checkedRun(jdk -> jdk.defaultJdk("12", false, FormatMixin.Format.text));
+		CaptureResult<Integer> result = checkedRun(jdk -> jdk.defaultJdk("12", false, false, FormatMixin.Format.text));
 
 		assertThat(result.result, equalTo(SUCCESS_EXIT));
 		assertThat(result.normalizedErr(), startsWith("[jbang] Default JDK set to 12"));
 
-		result = checkedRun(jdk -> jdk.defaultJdk(null, false, FormatMixin.Format.text));
+		result = checkedRun(jdk -> jdk.defaultJdk(null, false, false, FormatMixin.Format.text));
 
 		assertThat(result.result, equalTo(SUCCESS_EXIT));
 		assertThat(result.normalizedErr(), equalTo("[jbang] Default JDK is currently set to 12\n"));
@@ -101,12 +101,12 @@ void testDefault() throws Exception {
 	void testDefaultPlus() throws Exception {
 		Arrays.asList(11, 14, 17).forEach(this::createMockJdk);
 
-		CaptureResult<Integer> result = checkedRun(jdk -> jdk.defaultJdk("16+", false, FormatMixin.Format.text));
+		CaptureResult<Integer> result = checkedRun(jdk -> jdk.defaultJdk("16+", false, false, FormatMixin.Format.text));
 
 		assertThat(result.result, equalTo(SUCCESS_EXIT));
 		assertThat(result.normalizedErr(), startsWith("[jbang] Default JDK set to 17"));
 
-		result = checkedRun(jdk -> jdk.defaultJdk(null, false, FormatMixin.Format.text));
+		result = checkedRun(jdk -> jdk.defaultJdk(null, false, false, FormatMixin.Format.text));
 
 		assertThat(result.result, equalTo(SUCCESS_EXIT));
 		assertThat(result.normalizedErr(), equalTo("[jbang] Default JDK is currently set to 17\n"));
@@ -233,14 +233,15 @@ void testDefaultWithJavaHome() throws Exception {
 		initMockJdkDir(jdkPath, "12.0.7");
 		environmentVariables.set("JAVA_HOME", jdkPath.toString());
 
-		CaptureResult<Integer> result = checkedRun((Jdk jdk) -> jdk.defaultJdk("12", false, FormatMixin.Format.text),
+		CaptureResult<Integer> result = checkedRun(
+				(Jdk jdk) -> jdk.defaultJdk("12", false, false, FormatMixin.Format.text),
 				"jdk", "--jdk-providers",
 				"default,javahome,jbang");
 
 		assertThat(result.result, equalTo(SUCCESS_EXIT));
 		assertThat(result.normalizedErr(), startsWith("[jbang] Default JDK set to 12"));
 
-		result = checkedRun(jdk -> jdk.defaultJdk(null, false, FormatMixin.Format.text));
+		result = checkedRun(jdk -> jdk.defaultJdk(null, false, false, FormatMixin.Format.text));
 
 		assertThat(result.result, equalTo(SUCCESS_EXIT));
 		assertThat(result.normalizedErr(), equalTo("[jbang] Default JDK is currently set to 12\n"));