conversion executor interface

spring-binding/src/main/java/org/springframework/binding/convert/ConversionExecutor.java

@@ -15,113 +15,38 @@
  */
 package org.springframework.binding.convert;
 
-import org.springframework.core.style.ToStringCreator;
-import org.springframework.util.Assert;
-
 /**
  * A command object that is parameterized with the information necessary to perform a conversion of a source input to a
- * target output.
- * <p>
- * Specifically, encapsulates knowledge about how to convert source objects to a specific target type using a specific
+ * target output. Encapsulates knowledge about how to convert source objects to a specific target type using a specific
  * converter.
  * 
  * @author Keith Donald
  */
-public class ConversionExecutor {
-
-	/**
-	 * The source value type this executor will attempt to convert from.
-	 */
-	private final Class sourceClass;
-
-	/**
-	 * The target value type this executor will attempt to convert to.
-	 */
-	private final Class targetClass;
-
-	/**
-	 * The converter that will perform the conversion.
-	 */
-	private final Converter converter;
-
-	/**
-	 * Creates a conversion executor.
-	 * @param sourceClass the source type that the converter will convert from
-	 * @param targetClass the target type that the converter will convert to
-	 * @param converter the converter that will perform the conversion
-	 */
-	public ConversionExecutor(Class sourceClass, Class targetClass, Converter converter) {
-		Assert.notNull(sourceClass, "The source class is required");
-		Assert.notNull(targetClass, "The target class is required");
-		Assert.notNull(converter, "The converter is required");
-		this.sourceClass = sourceClass;
-		this.targetClass = targetClass;
-		this.converter = converter;
-	}
+public interface ConversionExecutor {
 
 	/**
 	 * Returns the source class of conversions performed by this executor.
 	 * @return the source class
 	 */
-	public Class getSourceClass() {
-		return sourceClass;
-	}
+	public Class getSourceClass();
 
 	/**
 	 * Returns the target class of conversions performed by this executor.
 	 * @return the target class
 	 */
-	public Class getTargetClass() {
-		return targetClass;
-	}
-
-	/**
-	 * Returns the converter that will perform the conversion.
-	 * @return the converter
-	 */
-	public Converter getConverter() {
-		return converter;
-	}
+	public Class getTargetClass();
 
 	/**
 	 * Execute the conversion for the provided source object.
 	 * @param source the source object to convert
 	 */
-	public Object execute(Object source) throws ConversionException {
-		return execute(source, null);
-	}
+	public Object execute(Object source) throws ConversionException;
 
 	/**
 	 * Execute the conversion for the provided source object.
 	 * @param source the source object to convert
 	 * @param context the conversion context, useful for influencing the behavior of the converter
 	 */
-	public Object execute(Object source, ConversionContext context) throws ConversionException {
-		if (getTargetClass().isInstance(source)) {
-			// source is already assignment compatible with target class
-			return source;
-		}
-		if (source != null && !getSourceClass().isInstance(source)) {
-			throw new ConversionException(getSourceClass(), source, getTargetClass(), "Source object '" + source
-					+ "' is expected to be an instance of " + getSourceClass());
-		}
-		return converter.convert(source, targetClass, context);
-	}
+	public Object execute(Object source, ConversionContext context) throws ConversionException;
 
-	public boolean equals(Object o) {
-		if (!(o instanceof ConversionExecutor)) {
-			return false;
-		}
-		ConversionExecutor other = (ConversionExecutor) o;
-		return sourceClass.equals(other.sourceClass) && targetClass.equals(other.targetClass);
-	}
-
-	public int hashCode() {
-		return sourceClass.hashCode() + targetClass.hashCode();
-	}
-
-	public String toString() {
-		return new ToStringCreator(this).append("sourceClass", sourceClass).append("targetClass", targetClass)
-				.toString();
-	}
 }