package com.atlassian.refapp.auth.internal;
   
   
   import org.apache.velocity.Template;
   import org.apache.velocity.VelocityContext;
   import org.apache.velocity.app.Velocity;
   import org.apache.velocity.app.VelocityEngine;
   import org.apache.velocity.runtime.log.JdkLogChute;
   import org.apache.velocity.runtime.resource.loader.ClasspathResourceLoader;
  import org.apache.velocity.tools.generic.EscapeTool;
  
  import javax.servlet.ServletConfig;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServlet;
  
  abstract class BaseVelocityServlet extends HttpServlet {
      // JavaDocs say this is threadsafe & stateless, so might as well share an instance
      // http://velocity.apache.org/tools/releases/1.3/javadoc/org/apache/velocity/tools/generic/EscapeTool.html
      private static final EscapeTool ESCAPE_TOOL = new EscapeTool();
  
      private final VelocityEngine velocity;
  
      public BaseVelocityServlet() {
          velocity = new VelocityEngine();
          velocity.addProperty(Velocity.RUNTIME_LOG_LOGSYSTEM_CLASS, JdkLogChute.class.getName());
          velocity.addProperty(Velocity.RESOURCE_LOADER, "classpath");
          velocity.addProperty("classpath.resource.loader.class", ClasspathResourceLoader.class.getName());
      }
  
  
      @Override
      public void init(ServletConfig config) throws ServletException {
          try {
              velocity.init();
          } catch (Exception e) {
              throw new ServletException(e);
          }
      }
  
      VelocityContext createDefaultVelocityContext() {
          final VelocityContext context = new VelocityContext();
          context.put("esc", ESCAPE_TOOL);
          return context;
      }
  
      Template getTemplate(final String templateName) throws ServletException {
          try {
              return velocity.getTemplate(templateName);
          } catch (Exception e) {
              throw new ServletException(e);
          }
      }
  }