Initializer.java :  » J2EE » wicket-1.4 » org » apache » wicket » velocity » Java Open Source

/*
 * 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.wicket.velocity;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import javax.servlet.ServletContext;

import org.apache.velocity.app.Velocity;
import org.apache.wicket.Application;
import org.apache.wicket.IInitializer;
import org.apache.wicket.WicketRuntimeException;
import org.apache.wicket.protocol.http.WebApplication;
import org.apache.wicket.util.file.WebApplicationPath;
import org.apache.wicket.util.resource.IResourceStream;
import org.apache.wicket.util.resource.ResourceStreamNotFoundException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * An implementation of {@link wicket.IInitializer} for the Velocity Runtime Singleton. If
 * Application is an instance of WebApplication, Initializer will retrieve
 * "velocityPropertiesFolder" as an initparam to point to the directory the properties file lives
 * in, and "velocity.properties" for the name of the properties file. If the params don't exist,
 * then velocity.properties next to this class will be loaded.
 * 
 */
public class Initializer implements IInitializer
{
  private static final Logger log = LoggerFactory.getLogger(Initializer.class);

  private String velocityPropertiesFile = "velocity.properties";

  private String velocityPropertiesFolder;

  /**
   * @see org.apache.wicket.IInitializer#init(org.apache.wicket.Application)
   */
  public void init(Application application)
  {
    Properties props = getVelocityProperties(application);

    try
    {
      if (null != props)
      {
        Velocity.init(props);
      }
      else
      {
        Velocity.init();
      }
      log.info("Initialized Velocity successfully");
    }
    catch (Exception e)
    {
      throw new WicketRuntimeException(e);
    }
  }

  private Properties getVelocityProperties(Application application)
  {
    if (application instanceof WebApplication)
    {
      WebApplication webapp = (WebApplication)application;
      ServletContext servletContext = webapp.getServletContext();
      ServletContext sc = servletContext;
      velocityPropertiesFolder = sc.getInitParameter("velocityPropertiesFolder");
      String propsFile = servletContext.getInitParameter("velocity.properties");

      if (null != propsFile)
      {
        velocityPropertiesFile = propsFile;
      }

      if (null != velocityPropertiesFolder)
      {
        WebApplicationPath webPath = new WebApplicationPath(sc);
        webPath.add(velocityPropertiesFolder);
        IResourceStream stream = webPath.find(Initializer.class, velocityPropertiesFile);
        InputStream is = null;
        try
        {
          is = stream.getInputStream();
          Properties props = new Properties();
          props.load(is);
          return props;
        }
        catch (IOException e)
        {
          throw new WicketRuntimeException(e);
        }
        catch (ResourceStreamNotFoundException e)
        {
          throw new WicketRuntimeException(e);
        }
        finally
        {
          if (is != null)
          {
            try
            {
              is.close();
            }
            catch (IOException e)
            {
              log.error(e.getMessage(), e);
            }
          }
        }
      }
    }

    // if it's not a web app, load from the package
    InputStream is = Initializer.class.getResourceAsStream("velocity.properties");
    try
    {
      Properties props = new Properties();
      props.load(is);
      return props;
    }
    catch (Exception e)
    {
      throw new WicketRuntimeException(e);
    }
    finally
    {
      if (is != null)
      {
        try
        {
          is.close();
        }
        catch (IOException e)
        {
          log.error(e.getMessage(), e);
        }
      }
    }
  }

}