blast.config.spring.GroupingPropertiesPlaceholderConfigurer.java Source code

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Here is the source code for blast.config.spring.GroupingPropertiesPlaceholderConfigurer.java

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/* Licensed 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 blast.config.spring;

import java.util.Enumeration;
import java.util.Properties;

import org.springframework.beans.propertyeditors.PropertiesEditor;
import org.springframework.web.context.support.ServletContextPropertyPlaceholderConfigurer;

/**
 * <b>Originally from Riot, at riotfamily.org.  Modified only slightly for more general use.
 * Original code licensed under Apache 2.0; license header kept intact above.</b>
 *
 * PropertyPlaceholderConfigurer that accepts wildcards to populate properties
 * that expect a java.util.Properties value.
 * <p>
 * Example:
 * <pre>
 * &lt;bean class="org.riotfamily.common.hibernate.RiotSessionFactoryBean"&gt;
 *   &lt;property name="hibernateProperties" value="${riot.(hibernate.*)}" /&gt;
 * &lt;/bean&gt;
 * </pre>
 *
 * The configurer will look for all properties start start with 
 * '<code>riot.hibernate.</code>'. So having a properties file like this ...
 * 
 * <pre>
 * riot.hibernate.cache.use_query_cache = true
 * riot.hibernate.show_sql = false
 * </pre>
 * 
 * ... would be equivalent to writing:
 * <pre>
 * &lt;bean class="org.riotfamily.common.hibernate.RiotSessionFactoryBean"&gt;
 *   &lt;property name="hibernateProperties"&gt;
 *     &lt;value&gt;
 *       hibernate.cache.use_query_cache = true
 *       hibernate.show_sql = false
 *     &lt/value&gt;
 *   &lt;/property&gt;
 * &lt;/bean&gt;
 * </pre>
 * 
 * Spring's {@link PropertiesEditor} will then take care of converting the 
 * String value into a <code>java.util.Properties</code> object.
 * 
 * <p>
 * Since Riot 9.0, the placeholder may contain parenthesis to indicate that 
 * a part of the placeholder should be included in the resulting keys. 
 * For example the placeholder <code>${riot.(hibernate.*)}</code> will result 
 * in keys that all start with <code>"hibernate."</code>. If the parenthesis 
 * were omitted, only the part matched by the asterisk would be used as key.
 *
 *
 * @author Felix Gnass [fgnass at neteye dot de], Matt Hoffman
 * @since 6.4
 */
public class GroupingPropertiesPlaceholderConfigurer extends ServletContextPropertyPlaceholderConfigurer {

    protected String resolvePlaceholder(String placeholder, Properties props) {
        int i = placeholder.indexOf('*');
        if (i != -1) {
            return resolveAll(props, placeholder.substring(0, i));
        }
        return super.resolvePlaceholder(placeholder, props);
    }

    protected String resolveAll(Properties props, String match) {
        String prefix = match;
        int i = match.indexOf('(');
        if (i != -1) {
            if (i > match.length() - 1) {
                prefix = match.substring(i + 1);
            } else {
                prefix = "";
            }
            match = match.substring(0, i) + prefix;
        }

        StringBuffer sb = new StringBuffer();
        Enumeration<?> names = props.propertyNames();
        while (names.hasMoreElements()) {
            String name = (String) names.nextElement();
            if (name.startsWith(match) && name.length() > match.length()) {
                sb.append(prefix);
                sb.append(name.substring(match.length()));
                sb.append('=');
                sb.append(props.getProperty(name));
                sb.append('\n');
            }
        }
        return sb.toString();
    }
}