org.apache.tomcat.util.digester.SetNextRule Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.tomcat.util.digester;
import org.apache.tomcat.util.IntrospectionUtils;
/**
* Rule implementation that calls a method on the (top-1) (parent)
* object, passing the top object (child) as an argument. It is
* commonly used to establish parent-child relationships.
*
* This rule now supports more flexible method matching by default.
* It is possible that this may break (some) code
* written against release 1.1.1 or earlier.
* See {@link #isExactMatch()} for more details.
*/
public class SetNextRule extends Rule {
// ----------------------------------------------------------- Constructors
/**
* Construct a "set next" rule with the specified method name.
*
* @param methodName Method name of the parent method to call
* @param paramType Java class of the parent method's argument
* (if you wish to use a primitive type, specify the corresponding
* Java wrapper class instead, such as java.lang.Boolean
* for a boolean parameter)
*/
public SetNextRule(String methodName,
String paramType) {
this.methodName = methodName;
this.paramType = paramType;
}
// ----------------------------------------------------- Instance Variables
/**
* The method name to call on the parent object.
*/
protected String methodName = null;
/**
* The Java class name of the parameter type expected by the method.
*/
protected String paramType = null;
/**
* Should we use exact matching. Default is no.
*/
protected boolean useExactMatch = false;
// --------------------------------------------------------- Public Methods
/**
* Is exact matching being used.
*
* This rule uses org.apache.commons.beanutils.MethodUtils
* to introspect the relevant objects so that the right method can be called.
* Originally, MethodUtils.invokeExactMethod was used.
* This matches methods very strictly
* and so may not find a matching method when one exists.
* This is still the behaviour when exact matching is enabled.
*
* When exact matching is disabled, MethodUtils.invokeMethod is used.
* This method finds more methods but is less precise when there are several methods
* with correct signatures.
* So, if you want to choose an exact signature you might need to enable this property.
*
* The default setting is to disable exact matches.
*
* @return true iff exact matching is enabled
* @since Digester Release 1.1.1
*/
public boolean isExactMatch() {
return useExactMatch;
}
/**
* Set whether exact matching is enabled.
*
* See {@link #isExactMatch()}.
*
* @param useExactMatch should this rule use exact method matching
* @since Digester Release 1.1.1
*/
public void setExactMatch(boolean useExactMatch) {
this.useExactMatch = useExactMatch;
}
/**
* Process the end of this element.
*
* @param namespace the namespace URI of the matching element, or an
* empty string if the parser is not namespace aware or the element has
* no namespace
* @param name the local name if the parser is namespace aware, or just
* the element name otherwise
*/
@Override
public void end(String namespace, String name) throws Exception {
// Identify the objects to be used
Object child = digester.peek(0);
Object parent = digester.peek(1);
if (digester.log.isTraceEnabled()) {
if (parent == null) {
digester.log.trace("[SetNextRule]{" + digester.match +
"} Call [NULL PARENT]." +
methodName + "(" + child + ")");
} else {
digester.log.trace("[SetNextRule]{" + digester.match +
"} Call " + parent.getClass().getName() + "." +
methodName + "(" + child + ")");
}
}
// Call the specified method
IntrospectionUtils.callMethod1(parent, methodName,
child, paramType, digester.getClassLoader());
StringBuilder code = digester.getGeneratedCode();
if (code != null) {
code.append(digester.toVariableName(parent)).append('.');
code.append(methodName).append('(').append(digester.toVariableName(child)).append(");");
code.append(System.lineSeparator());
}
}
/**
* Render a printable version of this Rule.
*/
@Override
public String toString() {
StringBuilder sb = new StringBuilder("SetNextRule[");
sb.append("methodName=");
sb.append(methodName);
sb.append(", paramType=");
sb.append(paramType);
sb.append(']');
return sb.toString();
}
}