pl.bristleback.server.bristle.config.ClassConfigurationUtil Maven / Gradle / Ivy

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// Bristleback plugin - Copyright (c) 2010 bristleback.googlecode.com
// ---------------------------------------------------------------------------
// This program is free software; you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License as published by the
// Free Software Foundation; either version 3 of the License, or (at your
// option) any later version.
// This library is distributed in the hope that it will be useful,
// but without any warranty; without even the implied warranty of merchantability
// or fitness for a particular purpose.
// You should have received a copy of the GNU Lesser General Public License along
// with this program; if not, see .
// ---------------------------------------------------------------------------
package pl.bristleback.server.bristle.config;

import org.apache.commons.lang.StringUtils;
import org.apache.log4j.Logger;
import pl.bristleback.server.bristle.exceptions.ImplementationResolvingException;
import pl.bristleback.server.bristle.exceptions.MissingPluginConfigurationElementException;
import pl.bristleback.server.bristle.integration.spring.SpringIntegrationUtil;
import pl.bristleback.server.bristle.utils.ResolverUtil;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * This class provides functions which can be used in user implementations of resolvers of various configuration elements.
 * 
 * Created on: 2010-10-14 21:11:19 

 *
 * @author Wojciech Niemiec
 */
public final class ClassConfigurationUtil {
  private static Logger log = Logger.getLogger(ClassConfigurationUtil.class.getName());

  public static final String SPRING_REF_PART = "_ref_";
  public static final String CLASS_TYPE_PART = "_class_";
  public static final String CLASS_NAME_PART = "_name_";

  private ClassConfigurationUtil() {
    throw new UnsupportedOperationException();
  }

  /**
   * Gets list of class elements taken from plugin settings with prefix given in constructor,
   * each bound in {@link pl.bristleback.server.bristle.config.ClassConfiguration} class.
   * Special convention of names is used here, user should provide only name of setting property.
   * For example, to get message sender classes, name of property prefix is: 'messageSender'.
   *
   * @param settingPrefix  prefix first part of setting property.
   * @param pluginSettings map of settings from plugin configuration.
   * @return list of class configuration.
   */
  public static List getClassConfigurationsFromSettingsMap(String settingPrefix, Map pluginSettings) {
    List classConfigurations = new ArrayList();
    int index = 0;

    String className = getClassNameForIndex(settingPrefix, pluginSettings, index);
    while (StringUtils.isNotEmpty(className)) {
      ClassConfiguration information = getClassConfigurationForIndex(settingPrefix, className, pluginSettings, index);
      classConfigurations.add(information);
      index++;
      className = getClassNameForIndex(settingPrefix, pluginSettings, index);
    }

    return classConfigurations;
  }

  private static ClassConfiguration getClassConfigurationForIndex(String settingPrefix, String className, Map pluginSettings, int index) {
    String springRef = getSenderSpringRefForIndex(settingPrefix, pluginSettings, index);
    String classType = getClassTypeForIndex(settingPrefix, pluginSettings, index);
    return createClassConfigurationInstance(className, springRef, classType);
  }

  private static ClassConfiguration createClassConfigurationInstance(String className, String springRef, String classType) {
    String type = getClassInstanceType(classType, springRef);
    boolean isSpringRef = StringUtils.isNotEmpty(springRef);
    return new ClassConfiguration(className, type, isSpringRef);
  }

  private static String getClassInstanceType(String senderClass, String senderSpringRef) {
    if (StringUtils.isNotEmpty(senderClass)) {
      return senderClass;
    } else if (StringUtils.isNotEmpty(senderSpringRef)) {
      return senderSpringRef;
    } else {
      throw new MissingPluginConfigurationElementException("message sender class or Spring reference");
    }
  }

  private static String getClassNameForIndex(String settingPrefix, Map pluginSettings, int index) {
    return pluginSettings.get(settingPrefix + CLASS_NAME_PART + index);
  }

  private static String getClassTypeForIndex(String settingPrefix, Map pluginSettings, int index) {
    return pluginSettings.get(settingPrefix + CLASS_TYPE_PART + index);
  }

  private static String getSenderSpringRefForIndex(String settingPrefix, Map pluginSettings, int index) {
    return pluginSettings.get(settingPrefix + SPRING_REF_PART + index);
  }

  public static  T getInstanceFromConfiguration(Class type, ClassConfiguration configuration) {
    if (configuration.isSpringType()) {
      return SpringIntegrationUtil.getSpringBean(configuration.getType(), type);
    } else {
      return retrieveInstance(type, configuration);
    }
  }

  /**
   * Returns instance of class from given class configuration. Method checks the way in which class should be retrieved.
   * Depending on configuration, it creates new instance of class or gets instance from Spring context.
   *
   * @param type          type of class.
   * @param configuration information about class.
   * @param            type of instance.
   * @return instance of class taken from configuration.
   */
  @SuppressWarnings("unchecked")
  private static  T retrieveInstance(Class type, ClassConfiguration configuration) {
    try {
      ResolverUtil resolverUtil = new ResolverUtil();
      Class senderClass = resolverUtil.getImplementation(type, configuration.getType());
      return senderClass.newInstance();
    } catch (Exception e) {
      throw new ImplementationResolvingException(configuration.getType(), type);
    }
  }
}