- /* $Id: FinderSetProperties.java,v 1.5 2004/05/10 06:34:01 skitching Exp $
- *
- * Copyright 2004 The Apache Software Foundation.
- *
- * 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 org.apache.commons.digester.plugins.strategies;
-
- import java.util.Properties;
- import java.io.InputStream;
- import java.io.FileInputStream;
- import java.io.IOException;
-
- import org.apache.commons.digester.Digester;
- import org.apache.commons.digester.plugins.RuleFinder;
- import org.apache.commons.digester.plugins.RuleLoader;
- import org.apache.commons.digester.plugins.PluginException;
-
- /**
- * A rule-finding algorithm which expects the user to specify whether
- * "automatic property setting" is desired. If this class discovers that
- * this is in fact the case for a declaration, then a RuleLoader is returned
- * which, when invoked, adds a single SetPropertiesRule instance to the
- * digester.
- * <p>
- * This allows ordinary JavaBean classes to be used as plugins, and have
- * xml attributes be mapped to bean properties of the same name, without
- * any custom plugin rules being created for them.
- * <p>
- * This RuleFinder is typically used as the <i>last</i> RuleFinder, so that
- * automatic property setting only occurs if there is no other source of
- * custom rules available.
- *
- * @since 1.6
- */
-
- public class FinderSetProperties extends RuleFinder {
- public static String DFLT_PROPS_ATTR = "setprops";
- public static String DFLT_FALSEVAL = "false";
-
- private String propsAttr;
- private String falseval;
-
- /** See {@link #findLoader}. */
- public FinderSetProperties() {
- this(DFLT_PROPS_ATTR, DFLT_FALSEVAL);
- }
-
- /**
- * Create a rule-finder which will arrange for a SetPropertiesRule to
- * be defined for each instance of a plugin, so that xml attributes
- * map to bean properties.
- * <p>
- * Param falseval will commonly be the string "false" for config files
- * written in English.
- *
- * @param propsAttr must be non-null.
- * @param falseval must be non-null.
- */
- public FinderSetProperties(String propsAttr, String falseval) {
- this.propsAttr = propsAttr;
- this.falseval = falseval;
- }
-
- /**
- * Returns a RuleLoader <i>unless</i> the properties contain an entry
- * with the name matching constructor param propsAttr, and the value
- * matching what is in falseval.
- * <p>
- * If no custom source of rules for a plugin is found, then the user
- * almost always wants xml attributes to map to java bean properties,
- * so this is the default behaviour unless the user explicitly indicates
- * that they do <i>not</i> want a SetPropertiesRule to be provided for
- * the plugged-in class.
- * <p>
- * The returned object (when non-null) will add a SetPropertiesRule to
- * the digester whenever its addRules method is invoked.
- */
- public RuleLoader findLoader(Digester d, Class pluginClass, Properties p) {
- String state = p.getProperty(propsAttr);
- if ((state != null) && state.equals(falseval)) {
- // user has explicitly disabled automatic setting of properties.
- // this is not expected to be common, but allowed.
- return null;
- }
-
- return new LoaderSetProperties();
- }
- }
-