Added java major version check utilities

Author: fugerit79

docgen/parameters.json

@@ -1,8 +1,8 @@
 {
 	"title" : "Jupiter (Fugerit Core A.P.I.)",
 	"name": "Jupiter",
-	"version" : "0.8.4",
-	"date" : "08/12/2021",
+	"version" : "0.8.5",
+	"date" : "20/12/2021",
 	"organization" : {
 		"name" : "Fugerit Org",
 		"url" : "https://www.fugerit.org"

docgen/release-notes.txt

@@ -1,4 +1,8 @@
-0.8.4 (2022-12-08)
+0.8.5 (2022-12-20)
+------------------
++ Added java major version check utilities
+
+0.8.4 (2022-12-08)
 ------------------
 + Added some Exception and RuntimeException utilities
 

fj-core/src/main/java/org/fugerit/java/core/lang/helpers/JavaVersionHelper.java

@@ -0,0 +1,49 @@
+package org.fugerit.java.core.lang.helpers;
+
+import org.fugerit.java.core.cfg.ConfigRuntimeException;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class JavaVersionHelper {
+
+	public static final int MAJOR_VERSION_JAVA_8 = 8;
+	
+	public static final int MAJOR_VERSION_JAVA_9 = 9;
+	
+	public static final int MAJOR_VERSION_JAVA_10 = 10;
+	
+	public static final int MAJOR_VERSION_JAVA_11 = 11;
+	
+	public static final int MAJOR_VERSION_FJ_CORE_REF = MAJOR_VERSION_JAVA_8;	// current reference version for fj-core library!
+	
+	private static final Logger logger = LoggerFactory.getLogger( JavaVersionHelper.class );
+	
+	private static final String SYS_PROP = "java.version";
+	
+	private static final String REMOVE_1_X = "1.";
+	
+	public static final int UNDEFINED = -1;
+	
+	public static int parseUniversalJavaMajorVersion() {
+		int res = UNDEFINED;
+		String javaVersion = System.getProperty( SYS_PROP );
+		if ( StringUtils.isEmpty( javaVersion ) ) {
+			throw new ConfigRuntimeException( "null property "+SYS_PROP );
+		} else {
+			logger.info( "{} -> {}", SYS_PROP, javaVersion );
+			if ( javaVersion.startsWith( REMOVE_1_X ) ) {
+				javaVersion = javaVersion.substring( REMOVE_1_X.length() );
+			}
+			int index = javaVersion.indexOf( '.' );
+			if ( index != -1 ) {
+				res = Integer.parseInt( javaVersion.substring( 0, index ) );
+				if ( res < MAJOR_VERSION_FJ_CORE_REF ) {
+					logger.info( "major version found : '{}' is lower than minimum required -> '{}'", res, MAJOR_VERSION_FJ_CORE_REF );
+				}
+			}
+			logger.info( "parseUniversalJavaMajorVersion -> '{}'", res );
+		}
+		return res;
+	}
+	
+}

fj-core/src/test/java/test/org/fugerit/java/core/lang/helpers/TestJavaVersionHelper.java

@@ -0,0 +1,20 @@
+package test.org.fugerit.java.core.lang.helpers;
+
+import org.fugerit.java.core.lang.helpers.JavaVersionHelper;
+import org.junit.Assert;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class TestJavaVersionHelper {
+	
+	private static final Logger logger = LoggerFactory.getLogger(TestJavaVersionHelper.class);
+
+	@Test
+	public void test() {
+		int majorVersion = JavaVersionHelper.parseUniversalJavaMajorVersion();
+		logger.info("major version -> '{}'", majorVersion);
+		Assert.assertEquals( "Wrong java major version" , JavaVersionHelper.MAJOR_VERSION_FJ_CORE_REF, majorVersion );
+	}
+
+}