SPR-7470

+ add c: namespace

org.springframework.beans/src/main/java/org/springframework/beans/factory/xml/SimpleConstructorNamespaceHandler.java

@@ -0,0 +1,151 @@
+/*
+ * Copyright 2010 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.beans.factory.xml;
+
+import java.util.Collection;
+
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.beans.factory.config.BeanDefinitionHolder;
+import org.springframework.beans.factory.config.ConstructorArgumentValues;
+import org.springframework.beans.factory.config.RuntimeBeanReference;
+import org.springframework.beans.factory.config.ConstructorArgumentValues.ValueHolder;
+import org.springframework.core.Conventions;
+import org.springframework.util.StringUtils;
+import org.w3c.dom.Attr;
+import org.w3c.dom.Element;
+import org.w3c.dom.Node;
+
+/**
+ * Simple <code>NamespaceHandler</code> implementation that maps custom
+ * attributes directly through to bean properties. An important point to note is
+ * that this <code>NamespaceHandler</code> does not have a corresponding schema
+ * since there is no way to know in advance all possible attribute names.
+ * 
+ * <p>
+ * An example of the usage of this <code>NamespaceHandler</code> is shown below:
+ * 
+ * <pre class="code">
+ * &lt;bean id=&quot;author&quot; class=&quot;..TestBean&quot; c:name=&quot;Enescu&quot; c:work-ref=&quot;compositions&quot;/&gt;
+ * </pre>
+ * 
+ * Here the '<code>c:name</code>' corresponds directly to the '<code>name</code>
+ * ' argument declared on the constructor of class '<code>TestBean</code>'. The
+ * '<code>c:work-ref</code>' attributes corresponds to the '<code>work</code>'
+ * argument and, rather than being the concrete value, it contains the name of
+ * the bean that will be considered as a parameter.
+ * 
+ * <b>Note</b>: This implementation supports only named parameters - there is no
+ * support for indexes or types. Further more, the names are used as hints by
+ * the container which, by default, does type introspection.
+ * 
+ * @see SimplePropertyNamespaceHandler
+ * @author Costin Leau
+ */
+public class SimpleConstructorNamespaceHandler implements NamespaceHandler {
+
+	private static final String REF_SUFFIX = "-ref";
+	private static final String DELIMITER_PREFIX = "_";
+
+	public void init() {
+	}
+
+	public BeanDefinition parse(Element element, ParserContext parserContext) {
+		parserContext.getReaderContext().error(
+				"Class [" + getClass().getName() + "] does not support custom elements.", element);
+		return null;
+	}
+
+	public BeanDefinitionHolder decorate(Node node, BeanDefinitionHolder definition, ParserContext parserContext) {
+		if (node instanceof Attr) {
+			Attr attr = (Attr) node;
+			String argName = StringUtils.trimWhitespace(parserContext.getDelegate().getLocalName(attr));
+			String argValue = StringUtils.trimWhitespace(attr.getValue());
+
+			ConstructorArgumentValues cvs = definition.getBeanDefinition().getConstructorArgumentValues();
+			boolean ref = false;
+
+			// handle -ref arguments
+			if (argName.endsWith(REF_SUFFIX)) {
+				ref = true;
+				argName = argName.substring(0, argName.length() - REF_SUFFIX.length());
+			}
+
+			ValueHolder valueHolder = new ValueHolder(ref ? new RuntimeBeanReference(argValue) : argValue);
+			valueHolder.setSource(parserContext.getReaderContext().extractSource(attr));
+
+			// handle "escaped"/"_" arguments
+			if (argName.startsWith(DELIMITER_PREFIX)) {
+				String arg = argName.substring(1).trim();
+
+				// fast default check 
+				if (!StringUtils.hasText(arg)) {
+					cvs.addGenericArgumentValue(valueHolder);
+				}
+				// assume an index otherwise
+				else {
+					int index = -1;
+					try {
+						index = Integer.parseInt(arg);
+					} catch (NumberFormatException ex) {
+						parserContext.getReaderContext().error(
+								"Constructor argument '" + argName + "' specifies an invalid integer", attr);
+					}
+					if (index < 0) {
+						parserContext.getReaderContext().error(
+								"Constructor argument '" + argName + "' specifies a negative index", attr);
+					}
+					
+					if (cvs.hasIndexedArgumentValue(index)){
+						parserContext.getReaderContext().error(
+								"Constructor argument '" + argName + "' with index "+ index+" already defined using <constructor-arg>." +
+								" Only one approach may be used per argument.", attr);
+					}
+					
+					cvs.addIndexedArgumentValue(index, valueHolder);
+				}
+			}
+			// no escaping -> ctr name
+			else {
+				String name = Conventions.attributeNameToPropertyName(argName);
+				if (containsArgWithName(name, cvs)){
+					parserContext.getReaderContext().error(
+							"Constructor argument '" + argName + "' already defined using <constructor-arg>." +
+							" Only one approach may be used per argument.", attr);
+				}
+				valueHolder.setName(Conventions.attributeNameToPropertyName(argName));
+				cvs.addGenericArgumentValue(valueHolder);
+			}
+		}
+		return definition;
+	}
+
+	private boolean containsArgWithName(String name, ConstructorArgumentValues cvs) {
+		if (!checkName(name, cvs.getGenericArgumentValues())) {
+			return checkName(name, cvs.getIndexedArgumentValues().values());
+		}
+
+		return true;
+	}
+	
+	private boolean checkName(String name, Collection<ValueHolder> values) {
+		for (ValueHolder holder : values) {
+			if (name.equals(holder.getName())) {
+				return true;
+			}
+		}
+		return false;
+	}
+}