Add an interface for ConfigBinder.

Rename the private implementation to ConfigBinderImpl, and
make ConfigBinder itself an interface.

src/main/java/com/dmdirc/config/ConfigBinder.java

@@ -22,55 +22,13 @@
 
 package com.dmdirc.config;
 
-import com.dmdirc.interfaces.config.AggregateConfigProvider;
-import com.dmdirc.interfaces.config.ConfigChangeListener;
-
-import com.google.common.collect.ArrayListMultimap;
-import com.google.common.collect.Multimap;
-
-import java.lang.reflect.AccessibleObject;
-import java.lang.reflect.Executable;
-import java.lang.reflect.Field;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collection;
-import java.util.Optional;
-
 import javax.annotation.Nonnull;
 
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-import static com.dmdirc.util.LogUtils.APP_ERROR;
-
 /**
  * Facilitates automatically binding fields or methods annotated with a {@link ConfigBinding}
  * element to a configuration value.
  */
-public class ConfigBinder {
-
-    private static final Logger LOG = LoggerFactory.getLogger(ConfigBinder.class);
-
-    /** A map of instances to created listeners. */
-    private final Multimap<Object, ConfigChangeListener> listeners = ArrayListMultimap.create();
-    /** The default domain to use. */
-    private final Optional<String> defaultDomain;
-    /** The configuration manager to use to retrieve settings. */
-    private final AggregateConfigProvider manager;
-    /** Retriever to use to get typed config values. */
-    private final ConfigValueRetriever valueRetriever;
-
-    ConfigBinder(final AggregateConfigProvider manager) {
-        this.manager = manager;
-        this.valueRetriever = new ConfigValueRetriever(manager);
-        this.defaultDomain = Optional.empty();
-    }
-
-    ConfigBinder(final AggregateConfigProvider manager, @Nonnull final String domain) {
-        this.manager = manager;
-        this.valueRetriever = new ConfigValueRetriever(manager);
-        this.defaultDomain = Optional.of(domain);
-    }
+public interface ConfigBinder {
 
     /**
      * Binds all annotated methods and fields of the given instance to this binder's configuration
@@ -79,129 +37,14 @@ public class ConfigBinder {
      * @param instance The instance to be bound
      * @param clazz    The class to read bindings from
      */
-    public void bind(final Object instance, final Class<?> clazz) {
-        final Collection<ConfigChangeListener> newListeners = new ArrayList<>();
-        final Collection<AccessibleObject> elements = new ArrayList<>();
-
-        elements.addAll(Arrays.asList(clazz.getDeclaredMethods()));
-        elements.addAll(Arrays.asList(clazz.getDeclaredFields()));
-
-        for (AccessibleObject element : elements) {
-            final ConfigBinding binding = element.getAnnotation(ConfigBinding.class);
-            if (binding != null) {
-                final ConfigChangeListener listener = getListener(instance, element, binding);
-                newListeners.add(listener);
-
-                manager.addChangeListener(getDomain(binding.domain()), binding.key(), listener);
-
-                for (int i = 0; i < binding.fallbacks().length - 1; i += 2) {
-                    manager.addChangeListener(getDomain(binding.fallbacks()[i]),
-                            binding.fallbacks()[i + 1], listener);
-                }
-
-                if (binding.applyInitially()) {
-                    updateBoundMember(instance, element, binding);
-                }
-            }
-        }
-
-        addListeners(instance, newListeners);
-    }
-
-    /**
-     * Returns the default domain for this binder if the given annotation-specified domain is empty.
-     */
-    private String getDomain(final String annotationDomain) {
-        return annotationDomain.isEmpty() ? defaultDomain.get() : annotationDomain;
-    }
-
-    /**
-     * Creates a new listener which will call
-     * {@link #updateBoundMember(Object, AccessibleObject, ConfigBinding)} with the given arguments.
-     *
-     * @param instance The instance to create a listener for
-     * @param element  The element to create a listener for
-     * @param binding  The binding annotation on the above element
-     *
-     * @return An appropriate config change listener
-     */
-    private ConfigChangeListener getListener(final Object instance,
-            final AccessibleObject element, final ConfigBinding binding) {
-        return (domain, key) -> updateBoundMember(instance, element, binding);
-    }
-
-    /**
-     * Updates the specified element of the given instance with the current value of the
-     * configuration key(s) specified by its binding.
-     *
-     * @param instance The instance to be updated
-     * @param element  The element to be updated
-     * @param binding  The binding which defines the configuration properties
-     */
-    private void updateBoundMember(final Object instance,
-            final AccessibleObject element, final ConfigBinding binding) {
-        if (!element.isAccessible()) {
-            element.setAccessible(true);
-        }
-
-        final Object value = valueRetriever.getValue(
-                getTargetClass(element),
-                getDomain(binding.domain()),
-                binding.key(),
-                binding.required(),
-                binding.fallbacks());
-
-        try {
-            binding.invocation().newInstance().invoke(element, instance, value);
-        } catch (ReflectiveOperationException ex) {
-            LOG.error(APP_ERROR, "Exception when updating bound setting", ex);
-        }
-    }
-
-    /**
-     * Gets the type required for setting the given element.
-     *
-     * @param element The element to determine a type for
-     *
-     * @return If the given element is a field, then the type of that field; if the element is a
-     *         method then the type of the first parameter; otherwise, <code>String.class</code>.
-     */
-    private Class<?> getTargetClass(final AccessibleObject element) {
-        if (element instanceof Field) {
-            return ((Field) element).getType();
-        }
-
-        if (element instanceof Executable) {
-            return ((Executable) element).getParameterTypes()[0];
-        }
-
-        return String.class;
-    }
-
-    /**
-     * Adds the given listeners to the given instance's collection.
-     *
-     * @param instance     The instance to add listeners for
-     * @param newListeners The listeners to be added
-     */
-    private void addListeners(final Object instance,
-            final Iterable<ConfigChangeListener> newListeners) {
-        synchronized (listeners) {
-            listeners.putAll(instance, newListeners);
-        }
-    }
+    void bind(final Object instance, final Class<?> clazz);
 
     /**
      * Unbinds all elements of the given instance that have been bound using this ConfigBinder.
      *
      * @param instance The instance to be unbound
      */
-    public void unbind(final Object instance) {
-        synchronized (listeners) {
-            listeners.get(instance).forEach(manager::removeListener);
-            listeners.removeAll(instance);
-        }
-    }
+    void unbind(final Object instance);
 
     /**
      * Returns a new config binder with the specified default domain.
@@ -209,8 +52,6 @@ public class ConfigBinder {
      * @param domain The default domain to use if one is not specified
      * @return A config binder with the specified default domain.
      */
-    public ConfigBinder withDefaultDomain(@Nonnull final String domain) {
-        return new ConfigBinder(manager, domain);
-    }
+    ConfigBinder withDefaultDomain(@Nonnull final String domain);
 
 }

src/main/java/com/dmdirc/config/ConfigBinderImpl.java

@@ -0,0 +1,179 @@
+package com.dmdirc.config;
+
+import com.dmdirc.interfaces.config.AggregateConfigProvider;
+import com.dmdirc.interfaces.config.ConfigChangeListener;
+
+import com.google.common.collect.ArrayListMultimap;
+import com.google.common.collect.Multimap;
+
+import java.lang.reflect.AccessibleObject;
+import java.lang.reflect.Executable;
+import java.lang.reflect.Field;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Optional;
+
+import javax.annotation.Nonnull;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import static com.dmdirc.util.LogUtils.APP_ERROR;
+
+/**
+ * Facilitates automatically binding fields or methods annotated with a {@link ConfigBinding}
+ * element to a configuration value.
+ */
+class ConfigBinderImpl implements ConfigBinder {
+
+    private static final Logger LOG = LoggerFactory.getLogger(ConfigBinder.class);
+
+    /** A map of instances to created listeners. */
+    private final Multimap<Object, ConfigChangeListener> listeners = ArrayListMultimap.create();
+    /** The default domain to use. */
+    private final Optional<String> defaultDomain;
+    /** The configuration manager to use to retrieve settings. */
+    private final AggregateConfigProvider manager;
+    /** Retriever to use to get typed config values. */
+    private final ConfigValueRetriever valueRetriever;
+
+    ConfigBinderImpl(final AggregateConfigProvider manager) {
+        this.manager = manager;
+        this.valueRetriever = new ConfigValueRetriever(manager);
+        this.defaultDomain = Optional.empty();
+    }
+
+    ConfigBinderImpl(final AggregateConfigProvider manager, @Nonnull final String domain) {
+        this.manager = manager;
+        this.valueRetriever = new ConfigValueRetriever(manager);
+        this.defaultDomain = Optional.of(domain);
+    }
+
+    @Override
+    public void bind(final Object instance, final Class<?> clazz) {
+        final Collection<ConfigChangeListener> newListeners = new ArrayList<>();
+        final Collection<AccessibleObject> elements = new ArrayList<>();
+
+        elements.addAll(Arrays.asList(clazz.getDeclaredMethods()));
+        elements.addAll(Arrays.asList(clazz.getDeclaredFields()));
+
+        for (AccessibleObject element : elements) {
+            final ConfigBinding binding = element.getAnnotation(ConfigBinding.class);
+            if (binding != null) {
+                final ConfigChangeListener listener = getListener(instance, element, binding);
+                newListeners.add(listener);
+
+                manager.addChangeListener(getDomain(binding.domain()), binding.key(), listener);
+
+                for (int i = 0; i < binding.fallbacks().length - 1; i += 2) {
+                    manager.addChangeListener(getDomain(binding.fallbacks()[i]),
+                            binding.fallbacks()[i + 1], listener);
+                }
+
+                if (binding.applyInitially()) {
+                    updateBoundMember(instance, element, binding);
+                }
+            }
+        }
+
+        addListeners(instance, newListeners);
+    }
+
+    /**
+     * Returns the default domain for this binder if the given annotation-specified domain is empty.
+     */
+    private String getDomain(final String annotationDomain) {
+        return annotationDomain.isEmpty() ? defaultDomain.get() : annotationDomain;
+    }
+
+    /**
+     * Creates a new listener which will call
+     * {@link #updateBoundMember(Object, AccessibleObject, ConfigBinding)} with the given arguments.
+     *
+     * @param instance The instance to create a listener for
+     * @param element  The element to create a listener for
+     * @param binding  The binding annotation on the above element
+     *
+     * @return An appropriate config change listener
+     */
+    private ConfigChangeListener getListener(final Object instance,
+            final AccessibleObject element, final ConfigBinding binding) {
+        return (domain, key) -> updateBoundMember(instance, element, binding);
+    }
+
+    /**
+     * Updates the specified element of the given instance with the current value of the
+     * configuration key(s) specified by its binding.
+     *
+     * @param instance The instance to be updated
+     * @param element  The element to be updated
+     * @param binding  The binding which defines the configuration properties
+     */
+    private void updateBoundMember(final Object instance,
+            final AccessibleObject element, final ConfigBinding binding) {
+        if (!element.isAccessible()) {
+            element.setAccessible(true);
+        }
+
+        final Object value = valueRetriever.getValue(
+                getTargetClass(element),
+                getDomain(binding.domain()),
+                binding.key(),
+                binding.required(),
+                binding.fallbacks());
+
+        try {
+            binding.invocation().newInstance().invoke(element, instance, value);
+        } catch (ReflectiveOperationException ex) {
+            LOG.error(APP_ERROR, "Exception when updating bound setting", ex);
+        }
+    }
+
+    /**
+     * Gets the type required for setting the given element.
+     *
+     * @param element The element to determine a type for
+     *
+     * @return If the given element is a field, then the type of that field; if the element is a
+     *         method then the type of the first parameter; otherwise, <code>String.class</code>.
+     */
+    private Class<?> getTargetClass(final AccessibleObject element) {
+        if (element instanceof Field) {
+            return ((Field) element).getType();
+        }
+
+        if (element instanceof Executable) {
+            return ((Executable) element).getParameterTypes()[0];
+        }
+
+        return String.class;
+    }
+
+    /**
+     * Adds the given listeners to the given instance's collection.
+     *
+     * @param instance     The instance to add listeners for
+     * @param newListeners The listeners to be added
+     */
+    private void addListeners(final Object instance,
+            final Iterable<ConfigChangeListener> newListeners) {
+        synchronized (listeners) {
+            listeners.putAll(instance, newListeners);
+        }
+    }
+
+    @Override
+    public void unbind(final Object instance) {
+        synchronized (listeners) {
+            listeners.get(instance).forEach(manager::removeListener);
+            listeners.removeAll(instance);
+        }
+    }
+
+    @Override
+    public ConfigBinder withDefaultDomain(@Nonnull final String domain) {
+        return new ConfigBinderImpl(manager, domain);
+    }
+
+}

src/main/java/com/dmdirc/config/ConfigManager.java

@@ -123,7 +123,7 @@ class ConfigManager implements ConfigChangeListener, ConfigProviderListener,
         this.server = server;
         this.channel = chanName;
 
-        binder = new ConfigBinder(this);
+        binder = new ConfigBinderImpl(this);
     }
 
     @Override

src/test/java/com/dmdirc/config/ConfigBinderTest.java → src/test/java/com/dmdirc/config/ConfigBinderImplTest.java

@@ -37,14 +37,14 @@ import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.when;
 
 @RunWith(MockitoJUnitRunner.class)
-public class ConfigBinderTest {
+public class ConfigBinderImplTest {
 
     @Mock private AggregateConfigProvider configProvider;
     private ConfigBinder binder;
 
     @Before
     public void setup() {
-        binder = new ConfigBinder(configProvider);
+        binder = new ConfigBinderImpl(configProvider);
     }
 
     @Test