Add test cases and re-org packages

src/main/java/org/springframework/classify/ClassifierAdapter.java

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+/*
+ * Copyright 2006-2007 the original author or authors.
+ *
+ * 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.springframework.classify;
+
+import org.springframework.classify.util.MethodInvoker;
+import org.springframework.classify.util.MethodInvokerUtils;
+import org.springframework.util.Assert;
+
+/**
+ * Wrapper for an object to adapt it to the {@link Classifier} interface.
+ * 
+ * @author Dave Syer
+ * 
+ */
+public class ClassifierAdapter<C, T> implements Classifier<C, T> {
+
+	private MethodInvoker invoker;
+
+	private Classifier<C, T> classifier;
+
+	/**
+	 * Default constructor for use with setter injection.
+	 */
+	public ClassifierAdapter() {
+		super();
+	}
+
+	/**
+	 * Create a new {@link Classifier} from the delegate provided. Use the
+	 * constructor as an alternative to the {@link #setDelegate(Object)} method.
+	 * 
+	 * @param delegate
+	 */
+	public ClassifierAdapter(Object delegate) {
+		setDelegate(delegate);
+	}
+
+	/**
+	 * Create a new {@link Classifier} from the delegate provided. Use the
+	 * constructor as an alternative to the {@link #setDelegate(Classifier)}
+	 * method.
+	 * 
+	 * @param delegate
+	 */
+	public ClassifierAdapter(Classifier<C, T> delegate) {
+		classifier = delegate;
+	}
+
+	public void setDelegate(Classifier<C, T> delegate) {
+		classifier = delegate;
+		invoker = null;
+	}
+
+	/**
+	 * Search for the
+	 * {@link org.springframework.classify.annotation.Classifier
+	 * Classifier} annotation on a method in the supplied delegate and use that
+	 * to create a {@link Classifier} from the parameter type to the return
+	 * type. If the annotation is not found a unique non-void method with a
+	 * single parameter will be used, if it exists. The signature of the method
+	 * cannot be checked here, so might be a runtime exception when the method
+	 * is invoked if the signature doesn't match the classifier types.
+	 * 
+	 * @param delegate an object with an annotated method
+	 */
+	public final void setDelegate(Object delegate) {
+		classifier = null;
+		invoker = MethodInvokerUtils.getMethodInvokerByAnnotation(
+				org.springframework.classify.annotation.Classifier.class, delegate);
+		if (invoker == null) {
+			invoker = MethodInvokerUtils.<C, T> getMethodInvokerForSingleArgument(delegate);
+		}
+		Assert.state(invoker != null, "No single argument public method with or without "
+				+ "@Classifier was found in delegate of type " + delegate.getClass());
+	}
+
+	/**
+	 * {@inheritDoc}
+	 */
+	@SuppressWarnings("unchecked")
+	public T classify(C classifiable) {
+		if (classifier != null) {
+			return classifier.classify(classifiable);
+		}
+		return (T) invoker.invokeMethod(classifiable);
+	}
+
+}