added jpa entity generator

src/java-jpa-entity.js

@@ -20,7 +20,7 @@ module.exports = {
                 let field_attr = field.attributes.find(attr => attr.name == 'jpa_sql')
 
 
-                field_attr = field_attr || {}
+                field_attr = field_attr && field_attr.value || {}
 
                 field.namePascalCase = utils.pascalcase(field.name);
                 field.isEnum = service.enums.find(e => e.name == field.type) != null