RequestParameterMapper.java
/*
* 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.commons.chain.web.jakarta.servlet;
import org.apache.commons.chain.Catalog;
import org.apache.commons.chain.Command;
import org.apache.commons.chain.Context;
import org.apache.commons.chain.generic.LookupCommand;
import jakarta.servlet.http.HttpServletRequest;
/**
* {@link Command} that uses a specified request parameter
* to select a {@link Command} from the appropriate {@link Catalog}, and
* execute it. To use this command, you would typically map an instance
* of {@link ChainProcessor} to a wildcard pattern like "*.execute" and
* then arrange that this is the default command to be executed. In such
* an environment, a request for the context-relative path
* "/foo.execute?command=bar" would cause the "/bar" command to be loaded
* and executed.
*
* @author Craig R. McClanahan
*/
public class RequestParameterMapper extends LookupCommand<ServletWebContext> {
// ------------------------------------------------------ Instance Variables
private String catalogKey = ChainProcessor.CATALOG_DEFAULT;
private String parameter = "command";
// ------------------------------------------------------------ Constructors
/**
* The Default-Constructor for this class.
*/
public RequestParameterMapper() {
}
// -------------------------------------------------------------- Properties
/**
* Return the context key under which our {@link Catalog} has been
* stored.
*
* @return The context key for the Catalog.
*/
public String getCatalogKey() {
return this.catalogKey;
}
/**
* Set the context key under which our {@link Catalog} has been
* stored.
*
* @param catalogKey The new catalog key
*
* @deprecated Use catalogName to specify the name of the catalog in the
* catalog factory
*/
@Deprecated
public void setCatalogKey(String catalogKey) {
this.catalogKey = catalogKey;
}
/**
* Return the name of the request parameter to use for
* selecting the {@link Command} to be executed.
*
* @return The name of the request parameter.
*
* @deprecated Use catalogName to specify the name of the catalog in the
* catalog factory
*/
@Deprecated
public String getParameter() {
return this.parameter;
}
/**
* Set the name of the request parameter to use for
* selecting the {@link Command} to be executed.
*
* @param parameter The new parameter name
*/
public void setParameter(String parameter) {
this.parameter = parameter;
}
// --------------------------------------------------------- Command Methods
/**
* Look up the specified request parameter for this request, and use it
* to select an appropriate {@link Command} to be executed.
*
* @param context Context for the current request
*
* @return The name of the {@link Command} instance
*
* @since Chain 1.2
*/
@Override
protected String getCommandName(ServletWebContext context) {
// Look up the specified request parameter for this request
HttpServletRequest request = context.getRequest();
String value = request.getParameter(getParameter());
return value;
}
/**
* Return the {@link Catalog} to look up the {@link Command} in.
*
* @param context {@link Context} for this request
*
* @return The catalog.
*
* @throws IllegalArgumentException if no {@link Catalog}
* can be found
*
* @since Chain 1.2
*/
@Override
protected Catalog<ServletWebContext> getCatalog(ServletWebContext context) {
/* If the object returned from the passed context is not a valid catalog
* then we use the super class's catalog extraction logic to pull it
* or to error gracefully.
*/
Object testCatalog = context.get(getCatalogKey());
/* Assume that the underlying implementation is following convention and
* returning a catalog with the current context.
*/
@SuppressWarnings("unchecked")
Catalog<ServletWebContext> catalog = testCatalog instanceof Catalog
? (Catalog<ServletWebContext>) testCatalog
: super.getCatalog(context);
return catalog;
}
}