org.apache.tomcat.util.digester.ObjectParamRule 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.xml.sax.Attributes;
/**
* Rule implementation that saves a parameter for use by a surrounding
* CallMethodRule.
*
* This parameter may be:
*
* - an arbitrary Object defined programatically, assigned when the element pattern associated with the Rule is matched
* See {@link #ObjectParamRule(int paramIndex, Object param)}
*
- an arbitrary Object defined programatically, assigned if the element pattern AND specified attribute name are matched
* See {@link #ObjectParamRule(int paramIndex, String attributeName, Object param)}
*
*
*
* @since 1.4
*/
public class ObjectParamRule extends Rule {
// ----------------------------------------------------------- Constructors
/**
* Construct a "call parameter" rule that will save the given Object as
* the parameter value.
*
* @param paramIndex The zero-relative parameter number
* @param param the parameter to pass along
*/
public ObjectParamRule(int paramIndex, Object param) {
this(paramIndex, null, param);
}
/**
* Construct a "call parameter" rule that will save the given Object as
* the parameter value, provided that the specified attribute exists.
*
* @param paramIndex The zero-relative parameter number
* @param attributeName The name of the attribute to match
* @param param the parameter to pass along
*/
public ObjectParamRule(int paramIndex, String attributeName, Object param) {
this.paramIndex = paramIndex;
this.attributeName = attributeName;
this.param = param;
}
// ----------------------------------------------------- Instance Variables
/**
* The attribute which we are attempting to match
*/
protected String attributeName = null;
/**
* The zero-relative index of the parameter we are saving.
*/
protected int paramIndex = 0;
/**
* The parameter we wish to pass to the method call
*/
protected Object param = null;
// --------------------------------------------------------- Public Methods
/**
* Process the start of this element.
*
* @param attributes The attribute list for this element
*/
@Override
public void begin(String namespace, String name,
Attributes attributes) throws Exception {
Object anAttribute = null;
Object parameters[] = (Object[]) digester.peekParams();
if (attributeName != null) {
anAttribute = attributes.getValue(attributeName);
if(anAttribute != null) {
parameters[paramIndex] = param;
}
// note -- if attributeName != null and anAttribute == null, this rule
// will pass null as its parameter!
}else{
parameters[paramIndex] = param;
}
}
/**
* Render a printable version of this Rule.
*/
@Override
public String toString() {
StringBuilder sb = new StringBuilder("ObjectParamRule[");
sb.append("paramIndex=");
sb.append(paramIndex);
sb.append(", attributeName=");
sb.append(attributeName);
sb.append(", param=");
sb.append(param);
sb.append("]");
return (sb.toString());
}
}