Add final modifier to new classes and complete javadoc
diff --git a/shardingsphere-elasticjob-lite-ui/shardingsphere-elasticjob-lite-ui-backend/src/main/java/org/apache/shardingsphere/elasticjob/lite/ui/exception/JdbcDriverNotFoundException.java b/shardingsphere-elasticjob-lite-ui/shardingsphere-elasticjob-lite-ui-backend/src/main/java/org/apache/shardingsphere/elasticjob/lite/ui/exception/JdbcDriverNotFoundException.java
index 546e906..5e69b3d 100644
--- a/shardingsphere-elasticjob-lite-ui/shardingsphere-elasticjob-lite-ui-backend/src/main/java/org/apache/shardingsphere/elasticjob/lite/ui/exception/JdbcDriverNotFoundException.java
+++ b/shardingsphere-elasticjob-lite-ui/shardingsphere-elasticjob-lite-ui-backend/src/main/java/org/apache/shardingsphere/elasticjob/lite/ui/exception/JdbcDriverNotFoundException.java
@@ -20,7 +20,7 @@
 /**
  * JDBC driver not found exception.
  */
-public class JdbcDriverNotFoundException extends RuntimeException {
+public final class JdbcDriverNotFoundException extends RuntimeException {
     
     public JdbcDriverNotFoundException(final String message) {
         super(String.format("Class not found: [%s]. Consider manually adding JDBC driver JAR to library path if you are trying connecting database.", message));
diff --git a/shardingsphere-elasticjob-lite-ui/shardingsphere-elasticjob-lite-ui-backend/src/main/java/org/apache/shardingsphere/elasticjob/lite/ui/web/handler/RestExceptionHandler.java b/shardingsphere-elasticjob-lite-ui/shardingsphere-elasticjob-lite-ui-backend/src/main/java/org/apache/shardingsphere/elasticjob/lite/ui/web/handler/RestExceptionHandler.java
index f0200f7..7203cf4 100644
--- a/shardingsphere-elasticjob-lite-ui/shardingsphere-elasticjob-lite-ui-backend/src/main/java/org/apache/shardingsphere/elasticjob/lite/ui/web/handler/RestExceptionHandler.java
+++ b/shardingsphere-elasticjob-lite-ui/shardingsphere-elasticjob-lite-ui-backend/src/main/java/org/apache/shardingsphere/elasticjob/lite/ui/web/handler/RestExceptionHandler.java
@@ -26,9 +26,12 @@
 
 import java.util.Optional;
 
+/**
+ * Define exception handlers.
+ */
 @Slf4j
 @RestControllerAdvice
-public class RestExceptionHandler {
+public final class RestExceptionHandler {
     
     @ExceptionHandler(JdbcDriverNotFoundException.class)
     public ResponseResult handleClassNotFoundException(final JdbcDriverNotFoundException ex) {