Refactor: to explicit Java (driver) class name loading

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 5.1.9
+  - Refactor: to explicit Java (driver) class name loading [#96](https://github.com/logstash-plugins/logstash-integration-jdbc/pull/96),
+    the change is expected to provide a more robust fix for the driver loading issue [#83](https://github.com/logstash-plugins/logstash-integration-jdbc/issues/83).
+
 ## 5.1.8
   - Fix the blocking pipeline reload and shutdown when connectivity issues happen [#85](https://github.com/logstash-plugins/logstash-integration-jdbc/pull/85)
 

lib/logstash/plugin_mixins/jdbc/common.rb

@@ -4,6 +4,8 @@ module Common
 
     private
 
+    # NOTE: using the JRuby mechanism to load classes (through JavaSupport)
+    # makes the lock redundant although it does not hurt to have it around.
     DRIVERS_LOADING_LOCK = java.util.concurrent.locks.ReentrantLock.new()
 
     def complete_sequel_opts(defaults = {})
@@ -30,16 +32,16 @@ def load_driver
       begin
         load_driver_jars
         begin
-          @driver_impl = Sequel::JDBC.load_driver(normalized_driver_class)
-        rescue Sequel::AdapterNotFound => e # Sequel::AdapterNotFound, "#{@jdbc_driver_class} not loaded"
-          # fix this !!!
+          @driver_impl = load_jdbc_driver_class
+        rescue => e # catch java.lang.ClassNotFoundException, potential errors
+          # (e.g. ExceptionInInitializerError or LinkageError) won't get caught
           message = if jdbc_driver_library_set?
                       "Are you sure you've included the correct jdbc driver in :jdbc_driver_library?"
                     else
                       ":jdbc_driver_library is not set, are you sure you included " +
                           "the proper driver client libraries in your classpath?"
                     end
-          raise LogStash::PluginLoadingError, "#{e}. #{message} #{e.backtrace}"
+          raise LogStash::PluginLoadingError, "#{e.inspect}. #{message}"
         end
       ensure
         DRIVERS_LOADING_LOCK.unlock()
@@ -71,16 +73,13 @@ def jdbc_driver_library_set?
       !@jdbc_driver_library.nil? && !@jdbc_driver_library.empty?
     end
 
-    # normalizing the class name to always have a Java:: prefix
-    # is helpful since JRuby is only able to directly load class names
-    # whose top-level package is com, org, java, javax
-    # There are many jdbc drivers that use cc, io, net, etc.
-    def normalized_driver_class
-      if @jdbc_driver_class.start_with?("Java::", "Java.")
-        @jdbc_driver_class
-      else
-        "Java::#{@jdbc_driver_class}"
-      end
+    def load_jdbc_driver_class
+      # sub a potential: 'Java::org::my.Driver' to 'org.my.Driver'
+      class_name = @jdbc_driver_class.gsub('::', '.').sub(/^Java\./, '')
+      # NOTE: JRuby's Java::JavaClass.for_name which considers the custom class-loader(s)
+      # in 9.3 the API changed and thus to avoid surprises we go down to the Java API :
+      JRuby.runtime.getJavaSupport.loadJavaClass(class_name) # throws ClassNotFoundException
     end
+
   end
 end end end

logstash-integration-jdbc.gemspec

@@ -1,6 +1,6 @@
 Gem::Specification.new do |s|
   s.name = 'logstash-integration-jdbc'
-  s.version         = '5.1.8'
+  s.version         = '5.1.9'
   s.licenses = ['Apache License (2.0)']
   s.summary         = "Integration with JDBC - input and filter plugins"
   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 gemname. This gem is not a stand-alone program"

spec/inputs/jdbc_spec.rb

@@ -1620,16 +1620,27 @@
   describe "jdbc_driver_class" do
     context "when not prefixed with Java::" do
       let(:jdbc_driver_class) { "org.apache.derby.jdbc.EmbeddedDriver" }
-      it "loads the class prefixed with Java::" do
-        expect(Sequel::JDBC).to receive(:load_driver).with(/^Java::/)
-        plugin.send(:load_driver)
+      it "loads the class" do
+        expect { plugin.send(:load_driver) }.not_to raise_error
       end
     end
     context "when prefixed with Java::" do
       let(:jdbc_driver_class) { "Java::org.apache.derby.jdbc.EmbeddedDriver" }
-      it "loads the class as-is" do
-        expect(Sequel::JDBC).to receive(:load_driver).with(jdbc_driver_class)
-        plugin.send(:load_driver)
+      it "loads the class" do
+        expect { plugin.send(:load_driver) }.not_to raise_error
+      end
+    end
+    context "when prefixed with Java." do
+      let(:jdbc_driver_class) { "Java.org::apache::derby::jdbc.EmbeddedDriver" }
+      it "loads the class" do
+        expect { plugin.send(:load_driver) }.not_to raise_error
+      end
+    end
+    context "when class name invalid" do
+      let(:jdbc_driver_class) { "org.apache.NonExistentDriver" }
+      it "raises a loading error" do
+        expect { plugin.send(:load_driver) }.to raise_error LogStash::PluginLoadingError,
+                                                            /java.lang.ClassNotFoundException: org.apache.NonExistentDriver/
       end
     end
   end