src/org/jsecurity/web/attr/RequestParamAttribute.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.jsecurity.web.attr;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

/**
 * @author Les Hazlewood
 * @since 0.2
 */
public class RequestParamAttribute<T> extends AbstractWebAttribute<T> {

    private static final Log log = LogFactory.getLog(RequestParamAttribute.class);    

    public RequestParamAttribute() {
        setMutable(false);
        setCheckRequestParams(false);
    }

    public RequestParamAttribute(String name) {
        super(name);
        setMutable(false);
        setCheckRequestParams(false);
    }

    protected T onRetrieveValue(ServletRequest request, ServletResponse response) {
        return getFromRequestParam(request);
    }

    protected void onStoreValue(T value, ServletRequest request, ServletResponse response) {
        throw new UnsupportedOperationException("RequestParamStores are read-only.");
    }

    public void removeValue(ServletRequest request, ServletResponse response) {
        //no op - can't alter request attributes
        if (log.isWarnEnabled()) {
            String msg = "Asked to remove WebAttribute value.  A " + getClass().getName() + " implementation " +
                    "cannot remove values from the request params.";
            log.warn(msg);
        }
    }
}