Refactoring the process of driver instances creation to use a new DriverProvider interface. DefaultDriverProvider wraps the current logic -- creating instances using reflection. This is a step to implement ability to load additional providers using ServiceLoader that can add new providers or override existing ones.

Author: barancev

java/server/src/org/openqa/selenium/remote/server/DefaultDriverFactory.java

@@ -20,64 +20,38 @@
 
 import org.openqa.selenium.Capabilities;
 import org.openqa.selenium.WebDriver;
-import org.openqa.selenium.WebDriverException;
 
-import java.lang.reflect.Constructor;
-import java.lang.reflect.InvocationTargetException;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
-import java.util.logging.Logger;
 
 public class DefaultDriverFactory implements DriverFactory {
 
-  private static final Logger log = Logger.getLogger(DefaultDriverFactory.class.getName());
-
-  private Map<Capabilities, Class<? extends WebDriver>> capabilitiesToDriver =
-      new ConcurrentHashMap<Capabilities, Class<? extends WebDriver>>();
+  private Map<Capabilities, DriverProvider> capabilitiesToDriverProvider =
+      new ConcurrentHashMap<Capabilities, DriverProvider>();
 
   public void registerDriver(Capabilities capabilities, Class<? extends WebDriver> implementation) {
-    capabilitiesToDriver.put(capabilities, implementation);
+    capabilitiesToDriverProvider.put(capabilities,
+                                     new DefaultDriverProvider(capabilities, implementation));
   }
 
   protected Class<? extends WebDriver> getBestMatchFor(Capabilities desired) {
+    return getProviderMatching(desired).getDriverClass();
+  }
+
+  protected DriverProvider getProviderMatching(Capabilities desired) {
     // We won't be able to make a match if no drivers have been registered.
-    checkState(!capabilitiesToDriver.isEmpty(),
-        "No drivers have been registered, will be unable to match %s", desired);
+    checkState(!capabilitiesToDriverProvider.isEmpty(),
+               "No drivers have been registered, will be unable to match %s", desired);
     Capabilities bestMatchingCapabilities =
-        CapabilitiesComparator.getBestMatch(desired, capabilitiesToDriver.keySet());
-    return capabilitiesToDriver.get(bestMatchingCapabilities);
+        CapabilitiesComparator.getBestMatch(desired, capabilitiesToDriverProvider.keySet());
+    return capabilitiesToDriverProvider.get(bestMatchingCapabilities);
   }
 
   public WebDriver newInstance(Capabilities capabilities) {
-    log.info("Creating a new session for " + capabilities);
-    Class<? extends WebDriver> clazz = getBestMatchFor(capabilities);
-
-    // Try and call the single arg constructor that takes a capabilities first
-    return callConstructor(clazz, capabilities);
-  }
-
-  private WebDriver callConstructor(Class<? extends WebDriver> from, Capabilities capabilities) {
-    try {
-      Constructor<? extends WebDriver> constructor = from.getConstructor(Capabilities.class);
-      return constructor.newInstance(capabilities);
-    } catch (NoSuchMethodException e) {
-      try {
-        return from.newInstance();
-      } catch (InstantiationException e1) {
-        throw new WebDriverException(e);
-      } catch (IllegalAccessException e1) {
-        throw new WebDriverException(e);
-      }
-    } catch (InvocationTargetException e) {
-      throw new WebDriverException(e);
-    } catch (InstantiationException e) {
-      throw new WebDriverException(e);
-    } catch (IllegalAccessException e) {
-      throw new WebDriverException(e);
-    }
+    return getProviderMatching(capabilities).newInstance(capabilities);
   }
 
   public boolean hasMappingFor(Capabilities capabilities) {
-    return capabilitiesToDriver.containsKey(capabilities);
+    return capabilitiesToDriverProvider.containsKey(capabilities);
   }
 }

java/server/src/org/openqa/selenium/remote/server/DefaultDriverProvider.java

@@ -0,0 +1,76 @@
+/*
+Copyright 2014 Selenium committers
+Copyright 2014 Software Freedom Conservancy
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+ */
+package org.openqa.selenium.remote.server;
+
+import org.openqa.selenium.Capabilities;
+import org.openqa.selenium.WebDriver;
+import org.openqa.selenium.WebDriverException;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.util.logging.Logger;
+
+public class DefaultDriverProvider implements DriverProvider {
+
+  private static final Logger log = Logger.getLogger(DefaultDriverProvider.class.getName());
+
+  private Capabilities capabilities;
+  private Class<? extends WebDriver> implementation;
+
+  public DefaultDriverProvider(Capabilities capabilities, Class<? extends WebDriver> implementation) {
+    this.capabilities = capabilities;
+    this.implementation = implementation;
+  }
+
+  @Override
+  public Capabilities getProvidedCapabilities() {
+    return capabilities;
+  }
+
+  @Override
+  public Class<? extends WebDriver> getDriverClass() {
+    return implementation;
+  }
+
+  @Override
+  public WebDriver newInstance(Capabilities capabilities) {
+    log.info("Creating a new session for " + capabilities);
+    // Try and call the single arg constructor that takes a capabilities first
+    return callConstructor(implementation, capabilities);
+  }
+
+  private WebDriver callConstructor(Class<? extends WebDriver> from, Capabilities capabilities) {
+    try {
+      Constructor<? extends WebDriver> constructor = from.getConstructor(Capabilities.class);
+      return constructor.newInstance(capabilities);
+    } catch (NoSuchMethodException e) {
+      try {
+        return from.newInstance();
+      } catch (InstantiationException e1) {
+        throw new WebDriverException(e);
+      } catch (IllegalAccessException e1) {
+        throw new WebDriverException(e);
+      }
+    } catch (InvocationTargetException e) {
+      throw new WebDriverException(e);
+    } catch (InstantiationException e) {
+      throw new WebDriverException(e);
+    } catch (IllegalAccessException e) {
+      throw new WebDriverException(e);
+    }
+  }
+}

java/server/src/org/openqa/selenium/remote/server/DriverProvider.java

@@ -0,0 +1,28 @@
+/*
+Copyright 2014 Selenium committers
+Copyright 2014 Software Freedom Conservancy
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+     http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+ */
+package org.openqa.selenium.remote.server;
+
+import org.openqa.selenium.Capabilities;
+import org.openqa.selenium.WebDriver;
+
+public interface DriverProvider {
+  Capabilities getProvidedCapabilities();
+
+  Class<? extends WebDriver> getDriverClass();
+
+  WebDriver newInstance(Capabilities capabilities);
+}

java/server/src/org/openqa/selenium/remote/server/build.desc

@@ -60,8 +60,10 @@ java_library(name = "server_very_core",
   srcs = [
     "CapabilitiesComparator.java",
     "DefaultDriverFactory.java",
+    "DefaultDriverProvider.java",
     "DefaultDriverSessions.java",
     "DriverFactory.java",
+    "DriverProvider.java",
     "DriverSessions.java",
     "KnownElements.java",
     "JsonHttpCommandHandler.java",