Merge "Allow experimental Java target 21 by default" into main

android/config.go

@@ -827,6 +827,10 @@ func (c *config) IsEnvFalse(key string) bool {
 	return value == "0" || value == "n" || value == "no" || value == "off" || value == "false"
 }
 
+func (c *config) TargetsJava21() bool {
+	return c.IsEnvTrue("EXPERIMENTAL_TARGET_JAVA_VERSION_21")
+}
+
 // EnvDeps returns the environment variables this build depends on. The first
 // call to this function blocks future reads from the environment.
 func (c *config) EnvDeps() map[string]string {

java/java.go

@@ -567,6 +567,12 @@ func getJavaVersion(ctx android.ModuleContext, javaVersion string, sdkContext an
 		return normalizeJavaVersion(ctx, javaVersion)
 	} else if ctx.Device() {
 		return defaultJavaLanguageVersion(ctx, sdkContext.SdkVersion(ctx))
+	} else if ctx.Config().TargetsJava21() {
+		// Temporary experimental flag to be able to try and build with
+		// java version 21 options.  The flag, if used, just sets Java
+		// 21 as the default version, leaving any components that
+		// target an older version intact.
+		return JAVA_VERSION_21
 	} else {
 		return JAVA_VERSION_17
 	}

java/sdk.go

@@ -65,6 +65,12 @@ func defaultJavaLanguageVersion(ctx android.EarlyModuleContext, s android.SdkSpe
 		return JAVA_VERSION_9
 	} else if sdk.FinalOrFutureInt() <= 33 {
 		return JAVA_VERSION_11
+	} else if ctx.Config().TargetsJava21() {
+		// Temporary experimental flag to be able to try and build with
+		// java version 21 options.  The flag, if used, just sets Java
+		// 21 as the default version, leaving any components that
+		// target an older version intact.
+		return JAVA_VERSION_21
 	} else {
 		return JAVA_VERSION_17
 	}