geode-core/src/main/java/org/apache/geode/internal/cache/xmlcache/CacheXmlPropertyResolver.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.geode.internal.cache.xmlcache;

import java.util.HashSet;
import java.util.Properties;

import org.apache.logging.log4j.Logger;

import org.apache.geode.internal.logging.LogService;

/**
 * Property resolver for resolving ${} like strings with system or Gemfire properties in Cache.xml
 *
 * @since GemFire 6.6
 */
public class CacheXmlPropertyResolver implements PropertyResolver {
  private static final Logger logger = LogService.getLogger();

  /**
   * Would not throw any exception {@link IllegalArgumentException} if property could not be
   * resolved
   */
  private boolean ignoreUnresolvedProperties = false;

  /** Would not throw any exception if property could not be resolved */
  private int propertyOverridden = SYSTEM_PROPERTIES_OVERRIDE;

  private CacheXmlPropertyResolverHelper helper = null;

  /**
   * A properties object to hold all user specified properties passed through .properties file or
   * passed as {@link Properties} objects. It will be set by <code>CacheXmlParser</code> if
   * gemfire.properties has to be included during replacement.
   */
  private Properties props = null;

  public CacheXmlPropertyResolver(boolean ignoreUnresolvedProperties, int propertyOverridden,
      Properties props) {
    super();
    this.ignoreUnresolvedProperties = ignoreUnresolvedProperties;
    this.propertyOverridden = propertyOverridden;
    this.props = props;
  }

  @Override
  public int getPropertyOverridden() {
    return propertyOverridden;
  }

  /**
   * Sets <code>propertyOverridden</code> with one of the constants specified in this
   * {@link CacheXmlPropertyResolver} class.
   *
   */
  public void setPropertyOverridden(int propertyOverridden) {
    this.propertyOverridden = propertyOverridden;
  }

  public void setIgnoreUnresolvedProperties(boolean ignoreUnresolvedProperties) {
    this.ignoreUnresolvedProperties = ignoreUnresolvedProperties;
  }

  @Override
  public boolean isIgnoreUnresolvedProperties() {
    return ignoreUnresolvedProperties;
  }

  /**
   * Resolves the given property string either from system properties or given properties. and
   * returns the replacement of the property found in available properties. If no string replacement
   * is found then {@link IllegalArgumentException} would be thrown based on
   * <code>ignoreUnresolvedProperties</code> flag being set by {@link CacheXmlParser}.
   *
   */
  @Override
  public String resolveReplaceString(String replaceString) {
    String replacement = null;

    // Get System property first.
    replacement = System.getProperty(replaceString);

    // Override system property if replacement is null or we want to override system property.
    if ((replacement == null || getPropertyOverridden() == SYSTEM_PROPERTIES_OVERRIDE)
        && props != null) {
      String userDefined = props.getProperty(replaceString);
      if (userDefined != null) {
        replacement = userDefined;
      }
    }
    return replacement;
  }

  @Override
  public String processUnresolvableString(String stringWithPrefixAndSuffix, String prefix,
      String suffix) {
    String resolvedString = null;
    try {
      if (helper == null) {
        helper = new CacheXmlPropertyResolverHelper(prefix, suffix);
      }
      /**
       * A <code>resolvedString</code> can be same as <code>stringWithPrefixAndSuffix</code> if
       * <code>ignoreUnresolvedProperties</code> is set true and we just return it as is.
       */
      resolvedString =
          helper.parseResolvablePropString(stringWithPrefixAndSuffix, this, new HashSet<String>());
    } catch (IllegalArgumentException e) {
      if (ignoreUnresolvedProperties) {
        // Do Nothing
      } else {
        logger.error("Format of the string {} used for perameterization is unresolvable",
            stringWithPrefixAndSuffix);
      }
    }
    return resolvedString;
  }

  public void setProps(Properties props) {
    this.props = props;
  }

  @Override
  public String processUnresolvableString(String stringWithPrefixAndSuffix) {
    return processUnresolvableString(stringWithPrefixAndSuffix, null, null);
  }
}