fix: fix execution of Java files + support UTF-8 encoding

Author: aminya

examples/HelloWorld.java

@@ -1,5 +1,6 @@
 class HelloWorld {
     public static void main(String[] args) {
         System.out.println("Hello, World!");
+        System.out.println("سلام");
     }
 }

lib/grammars/java.js

@@ -19,14 +19,9 @@ export const Java = {
       const className = GrammarUtils.Java.getClassName(context)
       const classPackages = GrammarUtils.Java.getClassPackage(context)
       const sourcePath = GrammarUtils.Java.getProjectPath(context)
-      if (windows) {
-        return [`/c javac ーJ-Dfile.encoding=UTF-8 -Xlint ${context.filename} && java -Dfile.encoding=UTF-8 ${className}`]
-      } else {
-        return [
-          "-c",
-          `javac -J-Dfile.encoding=UTF-8 -sourcepath '${sourcePath}' -d /tmp '${context.filepath}' && java -Dfile.encoding=UTF-8 -cp /tmp:%CLASSPATH ${classPackages}${className}`,
-        ]
-      }
+      const tempFolder = GrammarUtils.createTempFolder("jar-")
+      const cmd = `javac -encoding UTF-8 -sourcepath '${sourcePath}' -d '${tempFolder}' '${context.filepath}' && java -D'file.encoding'='UTF-8' -cp '${tempFolder}' ${classPackages}${className}`
+      return GrammarUtils.formatArgs(cmd)
     },
   },
 }