diff --git a/.rubocop.yml b/.rubocop.yml
new file mode 100644
index 0000000..07b0c63
--- /dev/null
+++ b/.rubocop.yml
@@ -0,0 +1,25 @@
+# I don't care for underscores in numbers.
+Style/NumericLiterals:
+  Enabled: false
+
+Style/ClassAndModuleChildren:
+  Enabled: false
+
+Metrics/AbcSize:
+  Enabled: false
+
+Metrics/CyclomaticComplexity:
+  Max: 9
+
+Metrics/PerceivedComplexity:
+  Max: 10
+
+Metrics/LineLength:
+  Enabled: false
+
+Metrics/MethodLength:
+  Max: 50
+
+Style/FileName:
+  Exclude:
+    - 'lib/logstash-output-jdbc_jars.rb'
diff --git a/Rakefile b/Rakefile
index a6ce4ea..dff9e9f 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,9 +1,9 @@
-require "logstash/devutils/rake"
+require 'logstash/devutils/rake'
 require 'jars/installer'
 
-desc "Fetch any jars required for this plugin"
+desc 'Fetch any jars required for this plugin'
 task :install_jars do
-  ENV['JARS_HOME'] = Dir.pwd + "/vendor/jar-dependencies/runtime-jars"
-  ENV['JARS_VENDOR'] = "false"
+  ENV['JARS_HOME'] = Dir.pwd + '/vendor/jar-dependencies/runtime-jars'
+  ENV['JARS_VENDOR'] = 'false'
   Jars::Installer.new.vendor_jars!(false)
 end
diff --git a/Vagrantfile b/Vagrantfile
index dc26e07..0796074 100644
--- a/Vagrantfile
+++ b/Vagrantfile
@@ -2,10 +2,10 @@
 # vi: set ft=ruby :
 
 Vagrant.configure(2) do |config|
-  config.vm.box = "debian/jessie64"
-  config.vm.synced_folder ".", "/vagrant", type: :virtualbox
+  config.vm.box = 'debian/jessie64'
+  config.vm.synced_folder '.', '/vagrant', type: :virtualbox
 
-  config.vm.provision "shell", inline: <<-EOP
+  config.vm.provision 'shell', inline: <<-EOP
     gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3
     curl -sSL https://get.rvm.io | bash -s stable --ruby=jruby-1.7
     usermod -a -G rvm vagrant
diff --git a/lib/logstash-output-jdbc_jars.rb b/lib/logstash-output-jdbc_jars.rb
index 4211f0f..d3fde26 100644
--- a/lib/logstash-output-jdbc_jars.rb
+++ b/lib/logstash-output-jdbc_jars.rb
@@ -1,5 +1,5 @@
 # encoding: utf-8
 require 'logstash/environment'
 
-root_dir = File.expand_path(File.join(File.dirname(__FILE__), ".."))
-LogStash::Environment.load_runtime_jars! File.join(root_dir, "vendor")
+root_dir = File.expand_path(File.join(File.dirname(__FILE__), '..'))
+LogStash::Environment.load_runtime_jars! File.join(root_dir, 'vendor')
diff --git a/lib/logstash/outputs/jdbc.rb b/lib/logstash/outputs/jdbc.rb
index f2a9c9a..0f2d1bf 100644
--- a/lib/logstash/outputs/jdbc.rb
+++ b/lib/logstash/outputs/jdbc.rb
@@ -1,27 +1,32 @@
 # encoding: utf-8
-require "logstash/outputs/base"
-require "logstash/namespace"
-require "concurrent"
-require "stud/interval"
-require "java"
-require "logstash-output-jdbc_jars"
+require 'logstash/outputs/base'
+require 'logstash/namespace'
+require 'concurrent'
+require 'stud/interval'
+require 'java'
+require 'logstash-output-jdbc_jars'
 
+# Write events to a SQL engine, using JDBC.
+#
+# It is upto the user of the plugin to correctly configure the plugin. This
+# includes correctly crafting the SQL statement, and matching the number of
+# parameters correctly.
 class LogStash::Outputs::Jdbc < LogStash::Outputs::Base
-  STRFTIME_FMT = "%Y-%m-%d %T.%L".freeze
+  STRFTIME_FMT = '%Y-%m-%d %T.%L'.freeze
 
   # Will never work, but only because it duplicates data (i.e. duplicate keys)
   # Will log a warning, but not retry.
   SQL_STATES_IGNORE = [
     ### Class: Unqualified Successful Completion
     # Success. This shouldn't get thrown, but JDBC driver quality varies, so who knows.
-    0000, 
-    
-    ### Class: Constraint Violation 
+    0000,
+
+    ### Class: Constraint Violation
     # Integrity constraint violation.
     23000,
     # A violation of the constraint imposed by a unique index or a unique constraint occurred.
     23505
-  ]
+  ].freeze
 
   # Will log an error, but not retry.
   SQL_STATES_FATAL = [
@@ -39,87 +44,84 @@ class LogStash::Outputs::Jdbc < LogStash::Outputs::Base
     # Character conversion resulted in truncation.
     22524,
 
-    ### Constraint Violation 
+    ### Constraint Violation
     # The insert or update value of a foreign key is invalid.
     23503,
     # The range of values for the identity column or sequence is exhausted.
     23522
-  ]
+  ].freeze
 
-  config_name "jdbc"
+  config_name 'jdbc'
 
   # Driver class - Reintroduced for https://github.com/theangryangel/logstash-output-jdbc/issues/26
-  config :driver_class, :validate => :string
+  config :driver_class, validate: :string
 
   # Does the JDBC driver support autocommit?
-  config :driver_auto_commit, :validate => :boolean, :default => true, :required => true
+  config :driver_auto_commit, validate: :boolean, default: true, required: true
 
   # Where to find the jar
   # Defaults to not required, and to the original behaviour
-  config :driver_jar_path, :validate => :string, :required => false
+  config :driver_jar_path, validate: :string, required: false
 
   # jdbc connection string
-  config :connection_string, :validate => :string, :required => true
+  config :connection_string, validate: :string, required: true
 
   # jdbc username - optional, maybe in the connection string
-  config :username, :validate => :string, :required => false
+  config :username, validate: :string, required: false
 
   # jdbc password - optional, maybe in the connection string
-  config :password, :validate => :string, :required => false
+  config :password, validate: :string, required: false
 
   # [ "insert into table (message) values(?)", "%{message}" ]
-  config :statement, :validate => :array, :required => true
+  config :statement, validate: :array, required: true
 
   # If this is an unsafe statement, use event.sprintf
-  # This also has potential performance penalties due to having to create a 
+  # This also has potential performance penalties due to having to create a
   # new statement for each event, rather than adding to the batch and issuing
   # multiple inserts in 1 go
-  config :unsafe_statement, :validate => :boolean, :default => false
+  config :unsafe_statement, validate: :boolean, default: false
 
   # Number of connections in the pool to maintain
-  config :max_pool_size, :validate => :number, :default => 5
+  config :max_pool_size, validate: :number, default: 5
 
   # Connection timeout
-  config :connection_timeout, :validate => :number, :default => 10000
+  config :connection_timeout, validate: :number, default: 10000
 
   # We buffer a certain number of events before flushing that out to SQL.
   # This setting controls how many events will be buffered before sending a
   # batch of events.
-  config :flush_size, :validate => :number, :default => 1000
+  config :flush_size, validate: :number, default: 1000
 
   # Set initial interval in seconds between retries. Doubled on each retry up to `retry_max_interval`
-  config :retry_initial_interval, :validate => :number, :default => 2
+  config :retry_initial_interval, validate: :number, default: 2
 
   # Maximum time between retries, in seconds
-  config :retry_max_interval, :validate => :number, :default => 128
+  config :retry_max_interval, validate: :number, default: 128
 
   # Maximum number of sequential failed attempts, before we stop retrying.
   # If set to < 1, then it will infinitely retry.
   # At the default values this is a little over 10 minutes
-  config :max_flush_exceptions, :validate => :number, :default => 10 
+  config :max_flush_exceptions, validate: :number, default: 10
 
-  config :max_repeat_exceptions, :obsolete => "This has been replaced by max_flush_exceptions - which behaves slightly differently. Please check the documentation."
-  config :max_repeat_exceptions_time, :obsolete => "This is no longer required"
-  config :idle_flush_time, :obsolete => "No longer necessary under Logstash v5"
+  config :max_repeat_exceptions, obsolete: 'This has been replaced by max_flush_exceptions - which behaves slightly differently. Please check the documentation.'
+  config :max_repeat_exceptions_time, obsolete: 'This is no longer required'
+  config :idle_flush_time, obsolete: 'No longer necessary under Logstash v5'
 
-  public
   def register
-    @logger.info("JDBC - Starting up")
+    @logger.info('JDBC - Starting up')
 
     LogStash::Logger.setup_log4j(@logger)
     load_jar_files!
 
     @stopping = Concurrent::AtomicBoolean.new(false)
 
-    if (@flush_size > 1000)
-      @logger.warn("JDBC - Flush size is set to > 1000")
+    @logger.warn('JDBC - Flush size is set to > 1000') if @flush_size > 1000
+
+    if @statement.empty?
+      @logger.error('JDBC - No statement provided. Configuration error.')
     end
 
-    if @statement.length < 1
-      @logger.error("JDBC - No statement provided. Configuration error.")
-    end
-
-    if (!@unsafe_statement and @statement.length < 2) 
+    if !@unsafe_statement && @statement.length < 2
       @logger.error("JDBC - Statement has no parameters. No events will be inserted into SQL as you're not passing any event data. Likely configuration error.")
     end
 
@@ -133,7 +135,7 @@ class LogStash::Outputs::Jdbc < LogStash::Outputs::Base
   end
 
   def teardown
-    @pool.close()
+    @pool.close
     super
   end
 
@@ -143,7 +145,7 @@ class LogStash::Outputs::Jdbc < LogStash::Outputs::Base
 
   private
 
-  def setup_and_test_pool!  
+  def setup_and_test_pool!
     # Setup pool
     @pool = Java::ComZaxxerHikari::HikariDataSource.new
 
@@ -161,47 +163,47 @@ class LogStash::Outputs::Jdbc < LogStash::Outputs::Base
     validate_connection_timeout = (@connection_timeout / 1000) / 2
 
     # Test connection
-    test_connection = @pool.getConnection()
+    test_connection = @pool.getConnection
     unless test_connection.isValid(validate_connection_timeout)
-      @logger.error("JDBC - Connection is not valid. Please check connection string or that your JDBC endpoint is available.")
+      @logger.error('JDBC - Connection is not valid. Please check connection string or that your JDBC endpoint is available.')
     end
-    test_connection.close()
+    test_connection.close
   end
 
   def load_jar_files!
     # Load jar from driver path
     unless @driver_jar_path.nil?
-      raise Exception.new("JDBC - Could not find jar file at given path. Check config.") unless File.exists? @driver_jar_path
+      raise Exception, 'JDBC - Could not find jar file at given path. Check config.' unless File.exist? @driver_jar_path
       require @driver_jar_path
       return
     end
 
     # Revert original behaviour of loading from vendor directory
     # if no path given
-    if ENV['LOGSTASH_HOME']
-      jarpath = File.join(ENV['LOGSTASH_HOME'], "/vendor/jar/jdbc/*.jar")
-    else
-      jarpath = File.join(File.dirname(__FILE__), "../../../vendor/jar/jdbc/*.jar")
-    end
+    jarpath = if ENV['LOGSTASH_HOME']
+                File.join(ENV['LOGSTASH_HOME'], '/vendor/jar/jdbc/*.jar')
+              else
+                File.join(File.dirname(__FILE__), '../../../vendor/jar/jdbc/*.jar')
+              end
 
-    @logger.debug("JDBC - jarpath", path: jarpath)
+    @logger.debug('JDBC - jarpath', path: jarpath)
 
     jars = Dir[jarpath]
-    raise Exception.new("JDBC - No jars found in jarpath. Have you read the README?") if jars.empty?
+    raise Exception, 'JDBC - No jars found. Have you read the README?' if jars.empty?
 
     jars.each do |jar|
-      @logger.debug("JDBC - Loaded jar", :jar => jar)
+      @logger.debug('JDBC - Loaded jar', jar: jar)
       require jar
     end
   end
-      
+
   def submit(events)
     connection = nil
     statement = nil
     events_to_retry = []
-    
+
     begin
-      connection = @pool.getConnection()
+      connection = @pool.getConnection
     rescue => e
       log_jdbc_exception(e)
       return events
@@ -209,19 +211,15 @@ class LogStash::Outputs::Jdbc < LogStash::Outputs::Base
 
     events.each do |event|
       begin
-        if @unsafe_statement == true
-          statement = connection.prepareStatement(event.sprintf(@statement[0]))
-        else
-          statement = connection.prepareStatement(@statement[0])
-        end
-        
+        statement = connection.prepareStatement(
+          (@unsafe_statement == true) ? event.sprintf(@statement[0]) : @statement[0]
+        )
         statement = add_statement_event_params(statement, event) if @statement.length > 1
-
-        statement.execute()
+        statement.execute
       rescue java.sql.SQLException => e
-        if SQL_STATES_IGNORE.include? e.getSQLState()
+        if SQL_STATES_IGNORE.include? e.getSQLState
           @logger.warn('JDBC - Dropping event. Ignore-able exception (duplicate key most likely)', exception: e, event: event)
-        elsif SQL_STATES_FATAL.include? e.getSQLState()
+        elsif SQL_STATES_FATAL.include? e.getSQLState
           @logger.error('JDBC - Fatal SQL exception. Can never succeed. Dropping event.', exception: e, event: event)
         else
           log_jdbc_exception(e)
@@ -229,16 +227,16 @@ class LogStash::Outputs::Jdbc < LogStash::Outputs::Base
         end
       rescue => e
         # Something else happened.
-        log_jdbc_exception(e)        
+        log_jdbc_exception(e)
         events_to_retry.push(event)
       ensure
-        statement.close() unless statement.nil?
+        statement.close unless statement.nil?
       end
     end
-    
-    connection.close() unless connection.nil?
 
-    return events_to_retry
+    connection.close unless connection.nil?
+
+    events_to_retry
   end
 
   def retrying_submit(actions)
@@ -248,7 +246,7 @@ class LogStash::Outputs::Jdbc < LogStash::Outputs::Base
     attempts = 0
 
     sleep_interval = @retry_initial_interval
-    while submit_actions && submit_actions.length > 0
+    while submit_actions && !submit_actions.empty?
       return if !submit_actions || submit_actions.empty? # If everything's a success we move along
       # We retry whatever didn't succeed
       submit_actions = submit(submit_actions)
@@ -279,10 +277,10 @@ class LogStash::Outputs::Jdbc < LogStash::Outputs::Base
         # See LogStash::Timestamp, below, for the why behind strftime.
         statement.setString(idx + 1, event.get(i).strftime(STRFTIME_FMT))
       when LogStash::Timestamp
-        # XXX: Using setString as opposed to setTimestamp, because setTimestamp 
+        # XXX: Using setString as opposed to setTimestamp, because setTimestamp
         # doesn't behave correctly in some drivers (Known: sqlite)
         #
-        # Additionally this does not use `to_iso8601`, since some SQL databases 
+        # Additionally this does not use `to_iso8601`, since some SQL databases
         # choke on the 'T' in the string (Known: Derby).
         #
         # strftime appears to be the most reliable across drivers.
@@ -293,12 +291,10 @@ class LogStash::Outputs::Jdbc < LogStash::Outputs::Base
         statement.setFloat(idx + 1, event.get(i))
       when String
         statement.setString(idx + 1, event.get(i))
-      when true
-        statement.setBoolean(idx + 1, true)
-      when false
-        statement.setBoolean(idx + 1, false)
+      when true, false
+        statement.setBoolean(idx + 1, event.get(i))
       else
-        if event.get(i).nil? and i =~ /%\{/
+        if event.get(i).nil? && i =~ /%\{/
           statement.setString(idx + 1, event.sprintf(i))
         else
           statement.setString(idx + 1, nil)
@@ -312,9 +308,9 @@ class LogStash::Outputs::Jdbc < LogStash::Outputs::Base
   def log_jdbc_exception(exception)
     current_exception = exception
     loop do
-      @logger.warn("JDBC Exception encountered: Will automatically retry.", :exception => current_exception)
-      current_exception = current_exception.getNextException()
-      break if current_exception == nil
+      @logger.warn('JDBC Exception encountered: Will automatically retry.', exception: current_exception)
+      current_exception = current_exception.getNextException
+      break if current_exception.nil?
     end
   end
 
diff --git a/logstash-output-jdbc.gemspec b/logstash-output-jdbc.gemspec
index 2f1c301..21fbe1a 100644
--- a/logstash-output-jdbc.gemspec
+++ b/logstash-output-jdbc.gemspec
@@ -1,38 +1,40 @@
 Gem::Specification.new do |s|
   s.name = 'logstash-output-jdbc'
-  s.version = "1.0.0.pre"
-  s.licenses = [ "Apache License (2.0)" ]
-  s.summary = "This plugin allows you to output to SQL, via JDBC"
+  s.version = '1.0.0.pre'
+  s.licenses = ['Apache License (2.0)']
+  s.summary = 'This plugin allows you to output to SQL, via JDBC'
   s.description = "This gem is a logstash plugin required to be installed on top of the Logstash core pipeline using $LS_HOME/bin/logstash-plugin install 'logstash-output-jdbc'. This gem is not a stand-alone program"
-  s.authors = ["the_angry_angel"]
-  s.email = "karl+github@theangryangel.co.uk"
-  s.homepage = "https://github.com/theangryangel/logstash-output-jdbc"
-  s.require_paths = [ "lib" ]
+  s.authors = ['the_angry_angel']
+  s.email = 'karl+github@theangryangel.co.uk'
+  s.homepage = 'https://github.com/theangryangel/logstash-output-jdbc'
+  s.require_paths = ['lib']
 
   # Java only
   s.platform = 'java'
 
   # Files
-  s.files = Dir.glob("{lib,spec}/**/*.rb") + Dir.glob("vendor/**/*") + %w(LICENSE.txt README.md)
+  s.files = Dir.glob('{lib,spec}/**/*.rb') + Dir.glob('vendor/**/*') + %w(LICENSE.txt README.md)
 
-   # Tests
+  # Tests
   s.test_files = s.files.grep(%r{^(test|spec|features)/})
 
   # Special flag to let us know this is actually a logstash plugin
-  s.metadata = { "logstash_plugin" => "true", "logstash_group" => "output" }
-   
+  s.metadata = { 'logstash_plugin' => 'true', 'logstash_group' => 'output' }
+
   # Gem dependencies
-  s.add_runtime_dependency "logstash-core-plugin-api", "~> 2.0"
+  s.add_runtime_dependency 'logstash-core-plugin-api', '~> 2.0'
   s.add_runtime_dependency 'stud'
-  s.add_runtime_dependency "logstash-codec-plain"
+  s.add_runtime_dependency 'logstash-codec-plain'
 
   # Stuck on HikariCP 2.4.2 until https://github.com/brettwooldridge/HikariCP/issues/600
   # is resolved.
   s.requirements << "jar 'com.zaxxer:HikariCP', '2.4.2'"
   s.requirements << "jar 'org.slf4j:slf4j-log4j12', '1.7.13'"
 
-  s.add_development_dependency "jar-dependencies"
+  s.add_development_dependency 'jar-dependencies'
   s.add_development_dependency 'ruby-maven', '~> 3.3'
 
-  s.add_development_dependency "logstash-devutils"
+  s.add_development_dependency 'logstash-devutils'
+
+  s.add_development_dependency 'rubocop'
 end
diff --git a/scripts/minutes_to_retries.rb b/scripts/minutes_to_retries.rb
index fcb20c6..b8fb502 100755
--- a/scripts/minutes_to_retries.rb
+++ b/scripts/minutes_to_retries.rb
@@ -1,7 +1,6 @@
 #!/usr/bin/env ruby -w
 
 seconds_to_reach = 10 * 60
-default_interval = 2
 retry_max_interval = 128
 
 current_interval = 2
@@ -9,10 +8,10 @@ total_interval = 0
 exceptions_count = 1
 
 loop do
-  break if total_interval > seconds_to_reach  
+  break if total_interval > seconds_to_reach
   exceptions_count += 1
-  
-  current_interval = current_interval*2 > retry_max_interval ? retry_max_interval : current_interval*2
+
+  current_interval = current_interval * 2 > retry_max_interval ? retry_max_interval : current_interval * 2
 
   total_interval += current_interval
 end
diff --git a/spec/jdbc_spec_helper.rb b/spec/jdbc_spec_helper.rb
index f712b57..4b26750 100644
--- a/spec/jdbc_spec_helper.rb
+++ b/spec/jdbc_spec_helper.rb
@@ -1,31 +1,26 @@
-require "logstash/devutils/rspec/spec_helper"
-require "logstash/outputs/jdbc"
-require "stud/temporary"
-require "java"
+require 'logstash/devutils/rspec/spec_helper'
+require 'logstash/outputs/jdbc'
+require 'stud/temporary'
+require 'java'
 require 'securerandom'
 
 RSpec.shared_context 'rspec setup' do
-
   it 'ensure jar is available' do
     expect(ENV[jdbc_jar_env]).not_to be_nil, "#{jdbc_jar_env} not defined, required to run tests"
-    expect(File.exists?(ENV[jdbc_jar_env])).to eq(true), "#{jdbc_jar_env} defined, but not valid"
+    expect(File.exist?(ENV[jdbc_jar_env])).to eq(true), "#{jdbc_jar_env} defined, but not valid"
   end
-
 end
 
 RSpec.shared_context 'when initializing' do
-
   it 'shouldn\'t register with a missing jar file' do
     jdbc_settings['driver_jar_path'] = nil
-    plugin = LogStash::Plugin.lookup("output", "jdbc").new(jdbc_settings)
+    plugin = LogStash::Plugin.lookup('output', 'jdbc').new(jdbc_settings)
     expect { plugin.register }.to raise_error
   end
-
 end
 
 RSpec.shared_context 'when outputting messages' do
-
-  let (:jdbc_test_table) do
+  let(:jdbc_test_table) do
     'logstash_output_jdbc_test'
   end
 
@@ -43,30 +38,28 @@ RSpec.shared_context 'when outputting messages' do
 
   let(:event) { LogStash::Event.new(event_fields) }
 
-  let(:plugin) {
+  let(:plugin) do
     # Setup plugin
-    output = LogStash::Plugin.lookup("output", "jdbc").new(jdbc_settings)
+    output = LogStash::Plugin.lookup('output', 'jdbc').new(jdbc_settings)
     output.register
-    if ENV['JDBC_DEBUG'] == '1'
-      output.logger.subscribe(STDOUT)
-    end
+    output.logger.subscribe(STDOUT) if ENV['JDBC_DEBUG'] == '1'
 
     # Setup table
-    c = output.instance_variable_get(:@pool).getConnection()
+    c = output.instance_variable_get(:@pool).getConnection
 
     unless jdbc_drop_table.nil?
-      stmt = c.createStatement()
+      stmt = c.createStatement
       stmt.executeUpdate(jdbc_drop_table)
-      stmt.close()
+      stmt.close
     end
 
-    stmt = c.createStatement()
+    stmt = c.createStatement
     stmt.executeUpdate(jdbc_create_table)
-    stmt.close()
-    c.close()
+    stmt.close
+    c.close
 
     output
-  }
+  end
 
   it 'should save a event' do
     expect { plugin.multi_receive([event]) }.to_not raise_error
@@ -74,18 +67,15 @@ RSpec.shared_context 'when outputting messages' do
     sleep 5
 
     # Verify the number of items in the output table
-    c = plugin.instance_variable_get(:@pool).getConnection()
+    c = plugin.instance_variable_get(:@pool).getConnection
     stmt = c.prepareStatement("select count(*) as total from #{jdbc_test_table} where message = ?")
     stmt.setString(1, event.get('message'))
-    rs = stmt.executeQuery()
+    rs = stmt.executeQuery
     count = 0
-    while rs.next()
-      count = rs.getInt("total")
-    end
-    stmt.close()
-    c.close()
+    count = rs.getInt('total') while rs.next
+    stmt.close
+    c.close
 
     expect(count).to eq(1)
   end
-
 end
diff --git a/spec/outputs/jdbc_derby_spec.rb b/spec/outputs/jdbc_derby_spec.rb
index 3f28a5e..652ed82 100644
--- a/spec/outputs/jdbc_derby_spec.rb
+++ b/spec/outputs/jdbc_derby_spec.rb
@@ -1,10 +1,9 @@
 require_relative '../jdbc_spec_helper'
 
-describe "logstash-output-jdbc: derby", if: ENV['JDBC_DERBY_JAR'] do
-
-  include_context "rspec setup"
-  include_context "when initializing"
-  include_context "when outputting messages"
+describe 'logstash-output-jdbc: derby', if: ENV['JDBC_DERBY_JAR'] do
+  include_context 'rspec setup'
+  include_context 'when initializing'
+  include_context 'when outputting messages'
 
   let(:jdbc_jar_env) do
     'JDBC_DERBY_JAR'
@@ -19,12 +18,11 @@ describe "logstash-output-jdbc: derby", if: ENV['JDBC_DERBY_JAR'] do
   end
 
   let(:jdbc_settings) do
-    { 
-      "driver_class" => "org.apache.derby.jdbc.EmbeddedDriver",
-      "connection_string" => "jdbc:derby:memory:testdb;create=true",
-      "driver_jar_path" => ENV[jdbc_jar_env],
-      "statement" => [ "insert into logstash_output_jdbc_test (created_at, message) values(?, ?)", "@timestamp", "message" ]
+    {
+      'driver_class' => 'org.apache.derby.jdbc.EmbeddedDriver',
+      'connection_string' => 'jdbc:derby:memory:testdb;create=true',
+      'driver_jar_path' => ENV[jdbc_jar_env],
+      'statement' => ['insert into logstash_output_jdbc_test (created_at, message) values(?, ?)', '@timestamp', 'message']
     }
   end
-
 end
diff --git a/spec/outputs/jdbc_mysql_spec.rb b/spec/outputs/jdbc_mysql_spec.rb
index 1e51f2c..fd4236c 100644
--- a/spec/outputs/jdbc_mysql_spec.rb
+++ b/spec/outputs/jdbc_mysql_spec.rb
@@ -1,22 +1,20 @@
-require_relative "../jdbc_spec_helper"
+require_relative '../jdbc_spec_helper'
 
-describe "logstash-output-jdbc: mysql", if: ENV['JDBC_MYSQL_JAR'] do
-
-  include_context "rspec setup"
-  include_context "when initializing"
-  include_context "when outputting messages"
+describe 'logstash-output-jdbc: mysql', if: ENV['JDBC_MYSQL_JAR'] do
+  include_context 'rspec setup'
+  include_context 'when initializing'
+  include_context 'when outputting messages'
 
   let(:jdbc_jar_env) do
     'JDBC_MYSQL_JAR'
   end
 
   let(:jdbc_settings) do
-    { 
-      "driver_class" => "com.mysql.jdbc.Driver",
-      "connection_string" => "jdbc:mysql://localhost/logstash_output_jdbc_test?user=root",
-      "driver_jar_path" => ENV[jdbc_jar_env],
-      "statement" => [ "insert into #{jdbc_test_table} (created_at, message) values(?, ?)", "@timestamp", "message" ]
+    {
+      'driver_class' => 'com.mysql.jdbc.Driver',
+      'connection_string' => 'jdbc:mysql://localhost/logstash_output_jdbc_test?user=root',
+      'driver_jar_path' => ENV[jdbc_jar_env],
+      'statement' => ["insert into #{jdbc_test_table} (created_at, message) values(?, ?)", '@timestamp', 'message']
     }
   end
-
 end
diff --git a/spec/outputs/jdbc_spec.rb b/spec/outputs/jdbc_spec.rb
index 13e8921..ad2d506 100644
--- a/spec/outputs/jdbc_spec.rb
+++ b/spec/outputs/jdbc_spec.rb
@@ -1,13 +1,11 @@
-require_relative "../jdbc_spec_helper"
+require_relative '../jdbc_spec_helper'
 
 describe LogStash::Outputs::Jdbc do
   context 'when initializing' do
-
     it 'shouldn\'t register without a config' do
-      expect { 
-        LogStash::Plugin.lookup("output", "jdbc").new()
-      }.to raise_error(LogStash::ConfigurationError)
+      expect do
+        LogStash::Plugin.lookup('output', 'jdbc').new
+      end.to raise_error(LogStash::ConfigurationError)
     end
-
   end
 end
diff --git a/spec/outputs/jdbc_sqlite_spec.rb b/spec/outputs/jdbc_sqlite_spec.rb
index eab0fb6..aa77d40 100644
--- a/spec/outputs/jdbc_sqlite_spec.rb
+++ b/spec/outputs/jdbc_sqlite_spec.rb
@@ -1,28 +1,26 @@
-require_relative "../jdbc_spec_helper"
+require_relative '../jdbc_spec_helper'
 
-describe "logstash-output-jdbc: sqlite", if: ENV['JDBC_SQLITE_JAR'] do
-
-  JDBC_SQLITE_FILE = "/tmp/logstash_output_jdbc_test.db"
+describe 'logstash-output-jdbc: sqlite', if: ENV['JDBC_SQLITE_JAR'] do
+  JDBC_SQLITE_FILE = '/tmp/logstash_output_jdbc_test.db'.freeze
 
   before(:context) do
-    File.delete(JDBC_SQLITE_FILE) if File.exists? JDBC_SQLITE_FILE
+    File.delete(JDBC_SQLITE_FILE) if File.exist? JDBC_SQLITE_FILE
   end
 
-  include_context "rspec setup"  
-  include_context "when initializing"
-  include_context "when outputting messages"
+  include_context 'rspec setup'
+  include_context 'when initializing'
+  include_context 'when outputting messages'
 
   let(:jdbc_jar_env) do
     'JDBC_SQLITE_JAR'
   end
 
   let(:jdbc_settings) do
-    { 
-      "driver_class" => "org.sqlite.JDBC",
-      "connection_string" => "jdbc:sqlite:#{JDBC_SQLITE_FILE}",
-      "driver_jar_path" => ENV[jdbc_jar_env],
-      "statement" => [ "insert into #{jdbc_test_table} (created_at, message) values(?, ?)", "@timestamp", "message" ]
+    {
+      'driver_class' => 'org.sqlite.JDBC',
+      'connection_string' => "jdbc:sqlite:#{JDBC_SQLITE_FILE}",
+      'driver_jar_path' => ENV[jdbc_jar_env],
+      'statement' => ["insert into #{jdbc_test_table} (created_at, message) values(?, ?)", '@timestamp', 'message']
     }
   end
-
 end