Tomcat4 简单wrapper责任链

TOMCAT4容器的责任链

public class SimpleWrapper implements Wrapper, Pipeline {



  private String servletClass;
  private SimplePipeline pipeline = new SimplePipeline(this);
  protected Container parent = null;
  
  public void invoke(Request request, Response response)
    throws IOException, ServletException {
    pipeline.invoke(request, response);
  }

  public Valve getBasic() {
    return pipeline.getBasic();
  }

  public void setBasic(Valve valve) {
    pipeline.setBasic(valve);
  }

  public Valve[] getValves() {
    return pipeline.getValves();
  }

  public void removeValve(Valve valve) {
    pipeline.removeValve(valve);
  }

}

public class SimplePipeline implements Pipeline {

  public SimplePipeline(Container container) {
    setContainer(container);
  }
  protected Valve basic = null;
  
  protected Container container = null;
  protected Valve valves[] = new Valve[0];



  public void addValve(Valve valve) {
    if (valve instanceof Contained)
      ((Contained) valve).setContainer(this.container);

    synchronized (valves) {
      Valve results[] = new Valve[valves.length +1];
      System.arraycopy(valves, 0, results, 0, valves.length);
      results[valves.length] = valve;
      valves = results;
    }
  }

  public void invoke(Request request, Response response)
    throws IOException, ServletException {
    
    (new SimplePipelineValveContext()).invokeNext(request, response);
  }
  protected class SimplePipelineValveContext implements ValveContext {

    protected int stage = 0;
    public void invokeNext(Request request, Response response)
      throws IOException, ServletException {
      int subscript = stage;
      stage = stage + 1;
   
      if (subscript < valves.length) {
        valves[subscript].invoke(request, response, this);
      }
      else if ((subscript == valves.length) && (basic != null)) {
        basic.invoke(request, response, this);
      }
      else {
        throw new ServletException("No valve");
      }
    }
  }
}