spring-webflow - 如何从这样的 URL 启动 Spring Web Flow/resource/edit/n

Question

我想使用 Spring Web Flow 主要是因为它的 PRG 功能。

假设我有像 /widget/edit/99 或 /widget/edit/123 这样的 URL，其中数字代表 id的小部件。

如何启动 /widget/edit 流程，传入 id？

默认情况下，流程 URL 必须与流程名称文件夹结构相匹配。

我想将 url 保留在 /widget/edit/99 而不是重定向。

(使用 2.4 版)

Answer 1

您需要尝试使用 FlowController 和 DefaultFlowUrlHandler。

FlowController - 它充当 Web Flow 定义的控制逻辑和 DispatcherServlet 的网关。

根据文档，在 DefaultFlowUrlHandler 中的 createFlowDefinitionUrl 方法中:

    The flow definition URL for the given flow id will be built by appending 
    the flow id to the base app context and servlet paths.

    Example - given a request originating at:
    http://someHost/someApp/someServlet/nestedPath/foo 

    and a request for the flow id "nestedPath/bar", the new flow definition URL
    would be:
    http://someHost/someApp/someServlet/nestedPath/bar      

因此，如果请求类似于:somehost/yourContextPath/yourServletContext/widget/edit/99 并且流 ID 是 widget/edit，则新的流定义 URL 将是:somehost/yourContextPath/yourServletContext/widget/edit

假设某些配置为:

web.xml 配置将“/widgetinventory/*”请求映射到 yourServletContext servlet:

    <servlet>
        <servlet-name>yourServletContext</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>yourServletContext</servlet-name>
        <url-pattern>/widgetinventory/*</url-pattern>
    </servlet-mapping>

你的ServletContext-servlet.xml:servlet 路径与“/widgetinventory//”匹配的所有请求都映射到“flowController”bean。

    <bean class="org.springframework.web.servlet.handler.SimpleUrlHandlerMapping">
        <property name="alwaysUseFullPath" value="true" />
        <property name="mappings">
            <value>/app/**/**=flowController</value>
        </property>
    </bean>

    <bean name="flowController" class="org.springframework.webflow.mvc.servlet.FlowController">
        <property name="flowExecutor" ref="flowExecutor" />
        <property name="flowUrlHandler" ref="customDefaultUrlhandler" />
    </bean>

    <bean id="customDefaultUrlhandler" class="package.CustomDefaultFlowUrlHandler"/>

    <flow:flow-executor id="flowExecutor" flow-registry="flowRegistry"/>

    <flow:flow-builder-services id="flowBuilderServices" view-factory-creator="viewFactoryCreator" validator="validator"/>

    <!-- Create the registry of flow definitions -->   
    <flow:flow-registry id="flowRegistry" base-path="/WEB-INF/flows/" flow-builder-services="flowBuilderServices">  
        <flow:flow-location-pattern value="**/*-flow.xml"/>
    </flow:flow-registry>

请参阅映射到 customDefaultUrlhandler 的 flowUrlHandler，它是 DefaultFlowUrlHandler 的扩展.有助于更改您在其中指定的流 url 的两个方法是:getFlowId 和 createFlowDefinitionUrl。

重写 DefaultFlowUrlHandler 中的 flowId 和 createFlowDefinitionUrl 方法。

但这一切都假设您的流 url 的类型为:somehost/{yourContextPath}/{yourServletContext}/widget/edit/99，其中 widget/edit 是 flowId，99 是一些 widgetId。

    public class CustomDefaultUrlhandler extends DefaultFlowUrlHandler{

    You need to alter flowId and createFlowDefinitionUrl if request is something like this:
    http://host/{yourContextPath}/{yourServletContext}/widget/edit/99 to direct to widget/edit flow

    @Override
    public String  getFlowId(HttpServletRequest request) {
        String pathInfo = request.getPathInfo(); // /widget/edit/99
        if (pathInfo != null) {
            String widgetId = pathInfo.substring(pathInfo.lastIndexOf("/") + 1);
            if(widgetId != null){
                return pathInfo.substring(1,pathInfo.lastIndexOf("/")); //return widget/edit by stripping /99
            }else{
                return pathInfo.substring(1); //return widget/edit
            }
        } else {
            String servletPath = request.getServletPath();
            if (StringUtils.hasText(servletPath)) {
                int dotIndex = servletPath.lastIndexOf('.');
                if (dotIndex != -1) {
                    return servletPath.substring(1, dotIndex);
                } else {
                    return servletPath.substring(1);
                }
            } else {
                String contextPath = request.getContextPath();
                if (StringUtils.hasText(contextPath)) {
                    return request.getContextPath().substring(1);
                } else {
                    return null;
                }
            }
        }
    }

    @Override
    public String  createFlowDefinitionUrl(String flowId, AttributeMap input, HttpServletRequest request) {
        //now flowId = "widget/edit"
        StringBuffer url = new StringBuffer();
        if (request.getPathInfo() != null) {
            //for /{yourContextPath}/{yourServletContext}/widget/edit/99 - pathInfo is /widget/edit/99          
            url.append(request.getContextPath());
            url.append(request.getServletPath());
            url.append('/');                    
            url.append(flowId);
        } else {
            String servletPath = request.getServletPath();
            if (StringUtils.hasText(servletPath)) {
                url.append(request.getContextPath());
                url.append('/');
                url.append(flowId);
                int dotIndex = servletPath.lastIndexOf('.');
                if (dotIndex != -1) {
                    url.append(servletPath.substring(dotIndex));
                }
            } else {
                url.append('/');
                url.append(flowId);
            }
        }
        if (input != null && !input.isEmpty()) {
            url.append('?');
            if (request.getPathInfo() != null) {
                //append your widget id here and retrieve this in flow by requestParameters el.
                String widgetId = pathInfo.substring(pathInfo.lastIndexOf("/") + 1);    
                url.append("widgetId ="+widgetId);
            }
            appendQueryParameters(url, input.asMap(), getEncodingScheme(request));
        }
        return url.toString();
    }
    }

基本上，我们根据您的 URL 自定义 flowid，并将 id 作为请求参数传递。

确保您的流程 ID 在您的场景中是 widget/edit。

在此处查看有关如何以所需格式获取流 ID 的链接:Spring Webflow - How to Get List of FLOW IDs