di-support

src/main/java/io/airlift/airline/Accessor.java

@@ -5,6 +5,7 @@
 import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
+import io.airlift.airline.factory.DefaultConstructorFactory;
 
 import java.lang.reflect.Field;
 import java.lang.reflect.ParameterizedType;
@@ -77,7 +78,7 @@ public Object getValue(Object instance)
             try {
                 Object nextInstance = intermediateField.get(instance);
                 if (nextInstance == null) {
-                    nextInstance = ParserUtil.createInstance(intermediateField.getType());
+                    nextInstance = new DefaultConstructorFactory().createInstance(intermediateField.getType());
                     intermediateField.set(instance, nextInstance);
                 }
                 instance = nextInstance;

src/main/java/io/airlift/airline/Cli.java

@@ -23,23 +23,22 @@
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.Iterables;
-import io.airlift.airline.model.ArgumentsMetadata;
-import io.airlift.airline.model.CommandGroupMetadata;
-import io.airlift.airline.model.CommandMetadata;
-import io.airlift.airline.model.GlobalMetadata;
-import io.airlift.airline.model.MetadataLoader;
-import io.airlift.airline.model.OptionMetadata;
+import io.airlift.airline.factory.CommandFactory;
+import io.airlift.airline.factory.DefaultConstructorFactory;
+import io.airlift.airline.model.*;
 
 import java.util.List;
 import java.util.Map;
 
 import static com.google.common.collect.Lists.newArrayList;
 import static com.google.common.collect.Maps.newHashMap;
-import static io.airlift.airline.ParserUtil.createInstance;
+import static io.airlift.airline.ParserUtil.configureInstance;
 
 public class Cli<C>
 {
-    public static <T> CliBuilder<T> builder(String name)
+	private final CommandFactory commandFactory;
+
+	public static <T> CliBuilder<T> builder(String name)
     {
         Preconditions.checkNotNull(name, "name is null");
         return new CliBuilder<T>(name);
@@ -64,9 +63,11 @@ private Cli(String name,
             TypeConverter typeConverter,
             Class<? extends C> defaultCommand,
             Iterable<Class<? extends C>> defaultGroupCommands,
-            Iterable<GroupBuilder<C>> groups)
+            Iterable<GroupBuilder<C>> groups,
+			CommandFactory commandFactory)
     {
-        Preconditions.checkNotNull(name, "name is null");
+		this.commandFactory = commandFactory;
+		Preconditions.checkNotNull(name, "name is null");
         Preconditions.checkNotNull(typeConverter, "typeConverter is null");
 
         CommandMetadata defaultCommandMetadata = null;
@@ -117,13 +118,14 @@ public C parse(Iterable<String> args)
 
         CommandMetadata command = state.getCommand();
 
-        return createInstance(command.getType(),
-                command.getAllOptions(),
-                state.getParsedOptions(),
-                command.getArguments(),
-                state.getParsedArguments(),
-                command.getMetadataInjections(),
-                ImmutableMap.<Class<?>, Object>of(GlobalMetadata.class, metadata));
+		C instance = (C) commandFactory.createInstance(command.getType());
+        return configureInstance(instance,
+				command.getAllOptions(),
+				state.getParsedOptions(),
+				command.getArguments(),
+				state.getParsedArguments(),
+				command.getMetadataInjections(),
+				ImmutableMap.<Class<?>, Object>of(GlobalMetadata.class, metadata));
     }
 
     private void validate(ParseState state)
@@ -168,6 +170,7 @@ public static class CliBuilder<C>
         protected final String name;
         protected String description;
         protected TypeConverter typeConverter = new TypeConverter();
+        protected CommandFactory commandFactory = new DefaultConstructorFactory();
         protected String optionSeparators;
         private Class<? extends C> defaultCommand;
         private final List<Class<? extends C>> defaultCommandGroupCommands = newArrayList();
@@ -202,11 +205,18 @@ public CliBuilder<C> withDescription(String description)
 //            return this;
 //        }
 
-        public CliBuilder<C> withDefaultCommand(Class<? extends C> defaultCommand)
-        {
-            this.defaultCommand = defaultCommand;
-            return this;
-        }
+
+		public CliBuilder<C> withCommandFactory(CommandFactory commandFactory)
+		{
+			this.commandFactory = commandFactory;
+			return this;
+		}
+
+		public CliBuilder<C> withDefaultCommand(Class<? extends C> defaultCommand)
+		{
+			this.defaultCommand = defaultCommand;
+			return this;
+		}
 
         public CliBuilder<C> withCommand(Class<? extends C> command)
         {
@@ -243,7 +253,7 @@ public GroupBuilder<C> withGroup(String name)
 
         public Cli<C> build()
         {
-            return new Cli<C>(name, description, typeConverter, defaultCommand, defaultCommandGroupCommands, groups.values());
+            return new Cli<C>(name, description, typeConverter, defaultCommand, defaultCommandGroupCommands, groups.values(), commandFactory);
         }
     }
 

src/main/java/io/airlift/airline/ParserUtil.java

@@ -12,30 +12,14 @@
 
 public class ParserUtil
 {
-    public static <T> T createInstance(Class<T> type)
+    public static <T> T configureInstance(T commandInstance,
+										  Iterable<OptionMetadata> options,
+										  ListMultimap<OptionMetadata, Object> parsedOptions,
+										  ArgumentsMetadata arguments,
+										  Iterable<Object> parsedArguments,
+										  Iterable<Accessor> metadataInjection,
+										  Map<Class<?>, Object> bindings)
     {
-        if (type != null) {
-            try {
-                return type.getConstructor().newInstance();
-            }
-            catch (Exception e) {
-                throw new ParseException(e, "Unable to create instance %s", type.getName());
-            }
-        }
-        return null;
-    }
-
-    public static <T> T createInstance(Class<?> type,
-            Iterable<OptionMetadata> options,
-            ListMultimap<OptionMetadata, Object> parsedOptions,
-            ArgumentsMetadata arguments,
-            Iterable<Object> parsedArguments,
-            Iterable<Accessor> metadataInjection,
-            Map<Class<?>, Object> bindings)
-    {
-        // create the command instance
-        T commandInstance = (T) ParserUtil.createInstance(type);
-
         // inject options
         for (OptionMetadata option : options) {
             List<?> values = parsedOptions.get(option);

src/main/java/io/airlift/airline/SingleCommand.java

@@ -20,6 +20,8 @@
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import io.airlift.airline.factory.CommandFactory;
+import io.airlift.airline.factory.DefaultConstructorFactory;
 import io.airlift.airline.model.ArgumentsMetadata;
 import io.airlift.airline.model.CommandMetadata;
 import io.airlift.airline.model.MetadataLoader;
@@ -28,7 +30,7 @@
 import java.util.List;
 
 import static com.google.common.base.Preconditions.checkNotNull;
-import static io.airlift.airline.ParserUtil.createInstance;
+import static io.airlift.airline.ParserUtil.configureInstance;
 
 public class SingleCommand<C>
 {
@@ -66,13 +68,15 @@ public C parse(Iterable<String> args)
 
         CommandMetadata command = state.getCommand();
 
-        return createInstance(command.getType(),
-                command.getAllOptions(),
-                state.getParsedOptions(),
-                command.getArguments(),
-                state.getParsedArguments(),
-                command.getMetadataInjections(),
-                ImmutableMap.<Class<?>, Object>of(CommandMetadata.class, commandMetadata));
+		CommandFactory commandFactory = new DefaultConstructorFactory();
+		final C instance = (C) commandFactory.createInstance(command.getType());
+		return configureInstance(instance,
+				command.getAllOptions(),
+				state.getParsedOptions(),
+				command.getArguments(),
+				state.getParsedArguments(),
+				command.getMetadataInjections(),
+				ImmutableMap.<Class<?>, Object>of(CommandMetadata.class, commandMetadata));
     }
 
     private void validate(ParseState state)

src/main/java/io/airlift/airline/SuggestCommand.java

@@ -4,6 +4,8 @@
 import com.google.common.base.Joiner;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
+import io.airlift.airline.factory.CommandFactory;
+import io.airlift.airline.factory.DefaultConstructorFactory;
 import io.airlift.airline.model.CommandGroupMetadata;
 import io.airlift.airline.model.CommandMetadata;
 import io.airlift.airline.model.GlobalMetadata;
@@ -17,7 +19,7 @@
 import java.util.concurrent.Callable;
 
 import static com.google.common.collect.Lists.newArrayList;
-import static io.airlift.airline.ParserUtil.createInstance;
+import static io.airlift.airline.ParserUtil.configureInstance;
 
 @Command(name = "suggest")
 public class SuggestCommand
@@ -57,13 +59,15 @@ public Iterable<String> generateSuggestions()
                     bindings.put(CommandMetadata.class, state.getCommand());
                 }
 
-                Suggester suggester = createInstance(suggesterMetadata.getSuggesterClass(),
-                        ImmutableList.<OptionMetadata>of(),
-                        null,
-                        null,
-                        null,
-                        suggesterMetadata.getMetadataInjections(),
-                        bindings.build());
+				CommandFactory commandFactory = new DefaultConstructorFactory();
+				final Suggester instance = commandFactory.createInstance(suggesterMetadata.getSuggesterClass());
+				Suggester suggester = configureInstance(instance,
+						ImmutableList.<OptionMetadata>of(),
+						null,
+						null,
+						null,
+						suggesterMetadata.getMetadataInjections(),
+						bindings.build());
 
                 return suggester.suggest();
             }

src/main/java/io/airlift/airline/factory/CommandFactory.java

@@ -0,0 +1,5 @@
+package io.airlift.airline.factory;
+
+public interface CommandFactory {
+	<T> T createInstance(Class<T> instanceClass);
+}

src/main/java/io/airlift/airline/factory/DefaultConstructorFactory.java

@@ -0,0 +1,18 @@
+package io.airlift.airline.factory;
+
+import io.airlift.airline.ParseException;
+
+public class DefaultConstructorFactory implements CommandFactory {
+	@Override
+	public <T> T createInstance(Class<T> type) {
+		if (type != null) {
+			try {
+				return type.getConstructor().newInstance();
+			}
+			catch (Exception e) {
+				throw new ParseException(e, "Unable to create instance %s", type.getName());
+			}
+		}
+		return null;
+	}
+}