edu.amc.sakai.user.PropertyResolver.java Source code

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Here is the source code for edu.amc.sakai.user.PropertyResolver.java

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/**********************************************************************************
 * $URL$
 * $Id$
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 *
 * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008 The Sakai Foundation
 *
 * Licensed under the Educational Community 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.opensource.org/licenses/ECL-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 edu.amc.sakai.user;

import java.io.IOException;
import java.util.Collection;
import java.util.HashSet;

import org.springframework.beans.factory.config.PropertyPlaceholderConfigurer;

public class PropertyResolver extends PropertyPlaceholderConfigurer {

    /**
     * Essentially a public version of {@link #parseStringValue(String, java.util.Properties, String)}
     * which takes a property name (without placeholder prefix or suffix) and returns the value
     * which would be injected into the <code>BeanFactory</code> at startup. Useful for
     * resolving configuration properties with recursive definitions.
     * 
     * <p>Somewhat fragile b/c we do not have access to the actual placeholder 
     * prefix/suffix values. Also not the fastest operation in the world... each call 
     * involves a call to {@link #mergeProperties()}.</p>
     * 
     * @param propertyName
     * @return
     */
    public String getStringValue(String propertyName) {
        try {
            return parseStringValue(DEFAULT_PLACEHOLDER_PREFIX + propertyName + DEFAULT_PLACEHOLDER_SUFFIX,
                    mergeProperties(), new HashSet());
        } catch (IOException e) {
            throw new RuntimeException("Failed to resolve property name [" + propertyName + "]");
        }
    }

    /** 
     * Access all property keys known to this {@link PropertyResolver}.
     * 
     * @return a disconnected collection of property keys
     */
    public Collection<String> getPropertyKeys() {
        try {
            return new HashSet(mergeProperties().keySet());
        } catch (IOException e) {
            throw new RuntimeException("Failed to generate property keyset", e);
        }
    }

}