struts1.3 & struts 1.2 RequestProcessor区别

struts1.2.9 ==============================

ActionServlet：

请求dopost或doget调用：
 protected void process(HttpServletRequest request, HttpServletResponse response)
        throws IOException, ServletException {

        ModuleUtils.getInstance().selectModule(request, getServletContext());
        ModuleConfig config = getModuleConfig(request);

        RequestProcessor processor = getProcessorForModule(config);
        if (processor == null) {
           processor = getRequestProcessor(config);
        }
//在1.2.9中使用RequestProcessor 实例
        processor.process(request, response);

    }
  
//第一次请求到来时调用
 protected synchronized RequestProcessor getRequestProcessor(ModuleConfig config)
        throws ServletException {

    RequestProcessor processor = this.getProcessorForModule(config);
    if (processor == null) {
            try {
                processor =
                    (RequestProcessor) RequestUtils.applicationInstance(
                        config.getControllerConfig().getProcessorClass());

 。。。。
} 

=====================================================
ActionServlet.init()
的 moduleConfig.freeze()方法
由子类ModuleConfigImpl.class实现

  getControllerConfig().freeze();

 public ControllerConfig getControllerConfig() {
        if (this.controllerConfig == null) {
            this.controllerConfig = new ControllerConfig();
        }
        return (this.controllerConfig);
    }

在ControllerConfig中有：
protected String processorClass =
        "org.apache.struts.action.RequestProcessor";

所以在上面
ActionServlet的getRequestProcessor方法中返回的是org.apache.struts.action.RequestProcessor并创建实例

======================================================
而1.3.10中
ControllerConfig改为：
protected String processorClass =
        "org.apache.struts.chain.ComposableRequestProcessor";
所以实际使用ComposableRequestProcessor类处理struts流程
=================================================

可以在struts-config.xml中添加：
<controller processorClass="org.apache.struts.action.RequestProcessor" />
指定RequestProcessor处理。