Converter: add type parameters

Added generic parameters for input and output types of the Covnerter
class. The return values for getInput and getOutput type methods have
been updated appropriately.

Author: hinerm

src/main/java/org/scijava/convert/AbstractConvertService.java

@@ -43,7 +43,7 @@
  * @author Mark Hiner
  */
 public abstract class AbstractConvertService extends
-	AbstractHandlerService<ConversionRequest, Converter> implements
+	AbstractHandlerService<ConversionRequest, Converter<?, ?>> implements
 	ConvertService
 {
 
@@ -58,13 +58,13 @@ public Object convert(Object src, Type dest) {
 	public <T> T convert(Object src, Class<T> dest) {
 		// NB: repeated code with convert(ConversionRequest), because the
 		// handler's convert method respects the T provided
-		Converter handler = getHandler(src, dest);
+		Converter<?, ?> handler = getHandler(src, dest);
 		return handler == null ? null : handler.convert(src, dest);
 	}
 
 	@Override
 	public Object convert(ConversionRequest request) {
-		Converter handler = getHandler(request);
+		Converter<?, ?> handler = getHandler(request);
 		return handler == null ? null : handler.convert(request);
 	}
 

src/main/java/org/scijava/convert/AbstractConverter.java

@@ -53,8 +53,8 @@
  *
  * @author Mark Hiner
  */
-public abstract class AbstractConverter extends
-	AbstractHandlerPlugin<ConversionRequest> implements Converter
+public abstract class AbstractConverter<I, O> extends
+	AbstractHandlerPlugin<ConversionRequest> implements Converter<I, O>
 {
 
 	// -- ConversionHandler methods --

src/main/java/org/scijava/convert/ConvertService.java

@@ -46,7 +46,7 @@
  * @author Mark Hiner
  */
 public interface ConvertService extends
-	HandlerService<ConversionRequest, Converter>
+	HandlerService<ConversionRequest, Converter<?, ?>>
 {
 	/**
 	 * @see Converter#convert(Object, Type)
@@ -66,22 +66,22 @@ public interface ConvertService extends
 	/**
 	 * @see #getHandler(ConversionRequest)
 	 */
-	Converter getHandler(Object src, Class<?> dest);
+	Converter<?, ?> getHandler(Object src, Class<?> dest);
 
 	/**
 	 * @see #getHandler(ConversionRequest)
 	 */
-	Converter getHandler(Class<?> src, Class<?> dest);
+	Converter<?, ?> getHandler(Class<?> src, Class<?> dest);
 
 	/**
 	 * @see #getHandler(ConversionRequest)
 	 */
-	Converter getHandler(Object src, Type dest);
+	Converter<?, ?> getHandler(Object src, Type dest);
 
 	/**
 	 * @see #getHandler(ConversionRequest)
 	 */
-	Converter getHandler(Class<?> src, Type dest);
+	Converter<?, ?> getHandler(Class<?> src, Type dest);
 
 	/**
 	 * @see #supports(ConversionRequest)

src/main/java/org/scijava/convert/Converter.java

@@ -47,7 +47,7 @@
  * @see ConversionRequest
  * @author Mark Hiner
  */
-public interface Converter extends HandlerPlugin<ConversionRequest>
+public interface Converter<I, O> extends HandlerPlugin<ConversionRequest>
 {
 
 	/**
@@ -183,10 +183,10 @@ public interface Converter extends HandlerPlugin<ConversionRequest>
 	/**
 	 * @return The base {@code Class} this {@code Converter} produces as output.
 	 */
-	Class<?> getOutputType();
+	Class<O> getOutputType();
 
 	/**
 	 * @return The base {@code Class} this {@code Converter} accepts as input.
 	 */
-	Class<?> getInputType();
+	Class<I> getInputType();
 }

src/main/java/org/scijava/convert/DefaultConvertService.java

@@ -49,9 +49,10 @@
 public class DefaultConvertService extends AbstractConvertService
 {
 
+	@SuppressWarnings({ "unchecked", "rawtypes" })
 	@Override
-	public Class<Converter> getPluginType() {
-		return Converter.class;
+	public Class<Converter<?, ?>> getPluginType() {
+		return (Class)Converter.class;
 	}
 
 	@Override
@@ -62,22 +63,22 @@ public Class<ConversionRequest> getType() {
 	// -- ConversionService methods --
 
 	@Override
-	public Converter getHandler(final Object src, final Class<?> dest) {
+	public Converter<?, ?> getHandler(final Object src, final Class<?> dest) {
 		return getHandler(new ConversionRequest(src, dest));
 	}
 
 	@Override
-	public Converter getHandler(final Class<?> src, final Class<?> dest) {
+	public Converter<?, ?> getHandler(final Class<?> src, final Class<?> dest) {
 		return getHandler(new ConversionRequest(src, dest));
 	}
 
 	@Override
-	public Converter getHandler(final Object src, final Type dest) {
+	public Converter<?, ?> getHandler(final Object src, final Type dest) {
 		return getHandler(new ConversionRequest(src, dest));
 	}
 
 	@Override
-	public Converter getHandler(final Class<?> src, final Type dest) {
+	public Converter<?, ?> getHandler(final Class<?> src, final Type dest) {
 		return getHandler(new ConversionRequest(src, dest));
 	}
 
@@ -105,7 +106,7 @@ public boolean supports(final Class<?> src, final Type dest) {
 	public Collection<Object> getCompatibleInputs(Class<?> dest) {
 		Set<Object> objects = new LinkedHashSet<Object>();
 
-		for (final Converter c : getInstances()) {
+		for (final Converter<?, ?> c : getInstances()) {
 			if (dest.isAssignableFrom(c.getOutputType())) {
 				c.populateInputCandidates(objects);
 			}

src/main/java/org/scijava/convert/DefaultConverter.java

@@ -55,7 +55,7 @@
  * @author Mark Hiner
  */
 @Plugin(type = Converter.class)
-public class DefaultConverter extends AbstractConverter {
+public class DefaultConverter extends AbstractConverter<Object, Object> {
 
 	// -- ConversionHandler methods --
 
@@ -266,12 +266,12 @@ public <T> T convert(final Object src, final Class<T> dest) {
 	}
 
 	@Override
-	public Class<?> getOutputType() {
+	public Class<Object> getOutputType() {
 		return Object.class;
 	}
 
 	@Override
-	public Class<?> getInputType() {
+	public Class<Object> getInputType() {
 		return Object.class;
 	}
 

src/main/java/org/scijava/util/ConversionUtils.java

@@ -51,7 +51,7 @@ public class ConversionUtils {
 
 	private static ConvertService convertService;
 
-	private static Converter converterNoContext;
+	private static Converter<?, ?> converterNoContext;
 
 	private static double servicePriority = 0.0;
 
@@ -195,7 +195,7 @@ public static void setDelegateService(final ConvertService convertService,
 	 */
 	@Deprecated
 	public static Object convert(final Object src, final Type dest) {
-		final Converter handler = handler(new ConversionRequest(src, dest));
+		final Converter<?, ?> handler = handler(new ConversionRequest(src, dest));
 		return (handler == null ? null : handler.convert(src, dest));
 	}
 
@@ -205,7 +205,7 @@ public static Object convert(final Object src, final Type dest) {
 	 */
 	@Deprecated
 	public static <T> T convert(final Object src, final Class<T> dest) {
-		final Converter handler = handler(new ConversionRequest(src, dest));
+		final Converter<?, ?> handler = handler(new ConversionRequest(src, dest));
 		return (handler == null ? null : handler.convert(src, dest));
 	}
 
@@ -215,7 +215,7 @@ public static <T> T convert(final Object src, final Class<T> dest) {
 	 */
 	@Deprecated
 	public static boolean canConvert(final Class<?> src, final Type dest) {
-		final Converter handler = handler(new ConversionRequest(src, dest));
+		final Converter<?, ?> handler = handler(new ConversionRequest(src, dest));
 		return (handler == null ? false : handler.canConvert(src, dest));
 	}
 
@@ -225,7 +225,7 @@ public static boolean canConvert(final Class<?> src, final Type dest) {
 	 */
 	@Deprecated
 	public static boolean canConvert(final Class<?> src, final Class<?> dest) {
-		final Converter handler = handler(new ConversionRequest(src, dest));
+		final Converter<?, ?> handler = handler(new ConversionRequest(src, dest));
 		return (handler == null ? false : handler.canConvert(src, dest));
 	}
 
@@ -235,7 +235,7 @@ public static boolean canConvert(final Class<?> src, final Class<?> dest) {
 	 */
 	@Deprecated
 	public static boolean canConvert(final Object src, final Type dest) {
-		final Converter handler = handler(new ConversionRequest(src, dest));
+		final Converter<?, ?> handler = handler(new ConversionRequest(src, dest));
 		return (handler == null ? false : handler.canConvert(src, dest));
 	}
 
@@ -245,7 +245,7 @@ public static boolean canConvert(final Object src, final Type dest) {
 	 */
 	@Deprecated
 	public static boolean canConvert(final Object src, final Class<?> dest) {
-		final Converter handler = handler(new ConversionRequest(src, dest));
+		final Converter<?, ?> handler = handler(new ConversionRequest(src, dest));
 		return (handler == null ? false : handler.canConvert(src, dest));
 	}
 
@@ -270,7 +270,7 @@ public static Class<?> getComponentClass(final Type type) {
 	 *
 	 * @return The {@link Converter} to use for handling the given request.
 	 */
-	private static Converter handler(final ConversionRequest data) {
+	private static Converter<?, ?> handler(final ConversionRequest data) {
 		if (convertService != null) return convertService.getHandler(data);
 
 		if (converterNoContext == null) converterNoContext = new DefaultConverter();

src/test/java/org/scijava/convert/ConvertServiceTest.java

@@ -578,7 +578,9 @@ public static enum Words {
 	 * methods are not implemented and are unnecessary.
 	 */
 	@Plugin(type = Converter.class, priority = Priority.LAST_PRIORITY)
-	public static class StringHisListConverter extends AbstractConverter {
+	public static class StringHisListConverter extends
+		AbstractConverter<String, HisList>
+	{
 
 		// Sample strings
 
@@ -598,12 +600,12 @@ public void populateInputCandidates(final Collection<Object> objects) {
 		}
 
 		@Override
-		public Class<?> getOutputType() {
+		public Class<HisList> getOutputType() {
 			return HisList.class;
 		}
 
 		@Override
-		public Class<?> getInputType() {
+		public Class<String> getInputType() {
 			return String.class;
 		}