Make it work also on JDK9 with new versioning scheme

Author: ctomc

src/main/java/org/codehaus/plexus/archiver/zip/AbstractZipArchiver.java

@@ -34,7 +34,6 @@
 import org.codehaus.plexus.util.FileUtils;
 import org.codehaus.plexus.util.IOUtil;
 
-import javax.annotation.WillClose;
 import java.io.ByteArrayInputStream;
 import java.io.File;
 import java.io.FileOutputStream;
@@ -119,8 +118,7 @@ public abstract class AbstractZipArchiver
      * Java versions from 8 and up round timestamp up.
      * s
      */
-    private static final boolean isJava7OrLower =
-        Integer.parseInt( System.getProperty( "java.version" ).split( "\\." )[1] ) <= 7;
+    private static final boolean isJava7OrLower = getJavaVersion()<= 7;
 
     // Renamed version of original file, if it exists
     private File renamedFile = null;
@@ -133,6 +131,16 @@ public abstract class AbstractZipArchiver
 
     protected ZipArchiveOutputStream zipArchiveOutputStream;
 
+    private static int getJavaVersion(){
+        String javaSpecVersion = System.getProperty( "java.specification.version" );
+        if (javaSpecVersion.contains(".")) {//before jdk 9
+            return Integer.parseInt(javaSpecVersion.split("\\.")[1]);
+        }else {
+            return Integer.parseInt(javaSpecVersion);
+        }
+    }
+
+
     public String getComment()
     {
         return comment;