Merge pull request #371 from matozoid/issue_370_compile_with_java_8

Set javaparser-core to compile with Java 8
diff --git a/javaparser-core/pom.xml b/javaparser-core/pom.xml
index 8f17434..9eb3bb2 100644
--- a/javaparser-core/pom.xml
+++ b/javaparser-core/pom.xml
@@ -24,7 +24,7 @@
     </licenses>
 
     <properties>
-        <java.version>1.6</java.version>
+        <java.version>1.8</java.version>
     </properties>
 
     <build>
@@ -60,7 +60,7 @@
                     <signature>
                         <!-- Make sure only the API of this JDK is used -->
                         <groupId>org.codehaus.mojo.signature</groupId>
-                        <artifactId>java16</artifactId>
+                        <artifactId>java18</artifactId>
                         <version>1.0</version>
                     </signature>
                 </configuration>
diff --git a/javaparser-core/src/main/javacc/java_1_8.jj b/javaparser-core/src/main/javacc/java_1_8.jj
index 9903907..3bf9af8 100644
--- a/javaparser-core/src/main/javacc/java_1_8.jj
+++ b/javaparser-core/src/main/javacc/java_1_8.jj
@@ -25,7 +25,7 @@
   JAVA_UNICODE_ESCAPE=true;
   COMMON_TOKEN_ACTION=true; // Using the CommonTokenAction callback to collect tokens for later usage
   //SUPPORT_CLASS_VISIBILITY_PUBLIC=false;
-  JDK_VERSION = "1.6";
+  JDK_VERSION = "1.8";
   TOKEN_FACTORY = "ASTParser.GTToken";
   JAVA_TEMPLATE_TYPE = "modern";
 }