filterconfig struts2执行流程(8)

prepare.findActionMapping(request, response, true)，源码如下：

public ActionMapping findActionMapping(HttpServletRequest request, HttpServletResponse response, boolean forceLookup) {
    ActionMapping mapping = (ActionMapping) request.getAttribute(STRUTS_ACTION_MAPPING_KEY);
    if (mapping == null || forceLookup) {
        try {
            // 这里就开始询问ActionMaper是否存在与该请求对应的业务控制类，详见下面的第三大步
            mapping = dispatcher.getContainer().getInstance(ActionMapper.class).getMapping(request, dispatcher.getConfigurationManager());
            if (mapping != null) {
                request.setAttribute(STRUTS_ACTION_MAPPING_KEY, mapping);
            }
        } catch (Exception ex) {
            dispatcher.sendError(request, response, servletContext, HttpServletResponse.SC_INTERNAL_SERVER_ERROR, ex);
        }
    }

    return mapping;
}

发现这个ActionMapping其实是通过ActionMapper的getMapping方法来获得的

ActionMapping getMapping(HttpServletRequest request, ConfigurationManager configManager);

发现这个ActionMapper是一个接口，这里我启动我的项目debug发现是调用了它的实现类：DefaultActionMapper的getMapping方法，实现细节如下：

tips：在eclipse中，按Ctrl+T可以查看当前类的子类或者实现类

public ActionMapping getMapping(HttpServletRequest request, ConfigurationManager configManager) {
    ActionMapping mapping = new ActionMapping();
    // 通过request工具类获取当前请求的uri
    String uri = RequestUtils.getUri(request);

    int indexOfSemicolon = uri.indexOf(";");
    uri = (indexOfSemicolon > -1) ? uri.substring(0, indexOfSemicolon) : uri;
    // 去掉后缀.action...
    uri = dropExtension(uri, mapping);
    if (uri == null) {
        return null;
    }
    // 解析出configManager里面设置的actionName和namespace并放入ActionMapping
    parseNameAndNamespace(uri, mapping, configManager);
    handleSpecialParameters(request, mapping);
    return parseActionName(mapping);
}

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