improve java version detection

Alipsa · Dec 27, 2021 · 1d3ceb0 · 1d3ceb0
1 parent 28df0f8
commit 1d3ceb0
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Showing 2 changed files with 24 additions and 1 deletion.
diff --git a/src/main/java/se/alipsa/ride/code/jstab/JsTab.java b/src/main/java/se/alipsa/ride/code/jstab/JsTab.java
@@ -17,6 +17,7 @@
 import se.alipsa.ride.console.ConsoleTextArea;
 import se.alipsa.ride.console.WarningAppenderWriter;
 import se.alipsa.ride.utils.ExceptionAlert;
+import se.alipsa.ride.utils.JavaVersion;
 
 import javax.script.ScriptContext;
 import javax.script.ScriptEngine;
@@ -59,7 +60,7 @@ public JsTab(String title, Ride gui) {
 
   public void initSession() {
     NashornScriptEngineFactory nashornScriptEngineFactory = new NashornScriptEngineFactory();
-    double jvmVersion = Double.parseDouble(System.getProperty("java.specification.version"));
+    int jvmVersion = JavaVersion.specVersion();
     String[] options;
     // Nashorn is part of the JDK until Java 14 but anything above 11 is not tested (it became deprecated in java 11)
     if (jvmVersion >= 11) {

diff --git a/src/main/java/se/alipsa/ride/utils/JavaVersion.java b/src/main/java/se/alipsa/ride/utils/JavaVersion.java
@@ -0,0 +1,22 @@
+package se.alipsa.ride.utils;
+
+
+public final class JavaVersion {
+
+  private JavaVersion() {
+    // Utility class
+  }
+
+  /**
+   *
+   * @return the java version currently running
+   * for java < 9 the right-hand side will be returned e.g 1.8 will become 8
+   */
+  public static int specVersion() {
+    double jvmVersion = Double.parseDouble(System.getProperty("java.specification.version"));
+    if (jvmVersion < 2) {
+      jvmVersion = (jvmVersion - 1) * 10;
+    }
+    return (int)Math.round(jvmVersion);
+  }
+}