Spring Web Flow中的复选框

时间：2014-04-16 19:39:33

标签： jsp checkbox spring-webflow

我正在开发一个在特定时刻使用Spring Web Flow的网站。在该流程中，有一个点（flow2.jsp），要求用户从一些复选框中进行选择。我看到的所有示例（如this和this）都获取了来自Controller类的复选框的项目......但由于我使用的是Spring Web Flow，因此我使用的是默认的flowController： 

<beans:bean id="flowcontroller" class="org.springframework.webflow.mvc.servlet.FlowController">
<beans:property name="flowExecutor" ref="flowExecutor"></beans:property>
</beans:bean>

我怎么能喂这些东西？我必须在JSP中对它们进行硬编码吗？

谢谢。

修改

我最终做了类似的事情，使用我的模型对象来初始化Map：

public Map referenceData(RequestContext context){
    System.out.println("Setting up list");
    Map referenceData=new HashMap();
    list=new ArrayList<String>();
    list.add("cb1");
    list.add("cb2");
    list.add("cb3");

    referenceData.put("list", list);

    return referenceData;
}

从flow.xml调用此方法：

<view-state id="flow2" view="flow2" model="proyecto">
    <on-render>
        <evaluate expression="proyecto.referenceData(flowRequestContext)"></evaluate>
    </on-render>

    <transition on="gotoPageThree" to="flow3"></transition>
    <transition on="goBack" to="inicio"></transition>
</view-state>

flow2.jsp是视图的名称：

<form:checkboxes items="${list}" path="property-in-my-model"/>

这样就抛出了异常：

java.lang.IllegalArgumentException: 'items' must not be null
at org.springframework.util.Assert.notNull(Assert.java:112)
at org.springframework.web.servlet.tags.form.AbstractMultiCheckedElementTag.setItems(AbstractMultiCheckedElementTag.java:83)
at org.apache.jsp.WEB_002dINF.views.flow2_jsp._jspx_meth_form_005fcheckboxes_005f0(flow2_jsp.java:170)
at org.apache.jsp.WEB_002dINF.views.flow2_jsp._jspx_meth_form_005fform_005f0(flow2_jsp.java:135)
at org.apache.jsp.WEB_002dINF.views.flow2_jsp._jspService(flow2_jsp.java:81)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:749)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:487)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:412)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:339)
at org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:238)
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:262)
at org.springframework.webflow.mvc.servlet.ServletMvcView.doRender(ServletMvcView.java:55)
at org.springframework.webflow.mvc.view.AbstractMvcView.render(AbstractMvcView.java:187)
at org.springframework.webflow.engine.ViewState.render(ViewState.java:296)
at org.springframework.webflow.engine.ViewState.refresh(ViewState.java:243)
at org.springframework.webflow.engine.ViewState.resume(ViewState.java:221)
at org.springframework.webflow.engine.Flow.resume(Flow.java:545)
at org.springframework.webflow.engine.impl.FlowExecutionImpl.resume(FlowExecutionImpl.java:258)
at org.springframework.webflow.executor.FlowExecutorImpl.resumeExecution(FlowExecutorImpl.java:169)
at org.springframework.webflow.mvc.servlet.FlowHandlerAdapter.handle(FlowHandlerAdapter.java:183)
at org.springframework.webflow.mvc.servlet.FlowController.handleRequest(FlowController.java:174)
at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:48)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:923)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:852)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:778)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:222)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:123)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:502)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:171)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:953)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1041)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:603)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:312)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)

我可以看到sysout出现在控制台之前，而不是Exception，所以我的模型对象应该有一个可以使用的列表......

1 个答案:

答案 0 :(得分：0)

Flow控制器是Spring MVC Controller层和Spring Web Flow引擎之间的适配器。它允许Spring Web Flow作为Controller在DispatcherServlet中运行。流控制器确定在请求到达时要执行的操作，如启动新流程执行，恢复暂停流程执行，停止流程执行。 它不会处理表单元素。

您需要创建一个类（比如登录，登录服务类），在进入流程的下一个屏幕之前处理与表单相关的内容。

例如，创建一个Class来处理登录流程操作：

    public class LoginAction implements Seerilaizable{
        ...
        public void performPostLoginProcess(LoginForm loginForm){
            ..
        }
    }

创建一个表单来保存视图中定义的表单字段（通常我只使用一个表单来处理具有多个视图的整个流程，但根据需求，我们每个流程可以有多个表单）：

    public class LoginForm implements Seerilaizable{
        //Your jsp view has these fields
        private boolean checkBox1;
        private String textField1;
        ...
    }

在调度程序servlet上下文中定义此bean，如：

    <bean id="loginAction" class="package.LoginAction">
        <property>...</property>
    <bean>

在您的流程中：

    <start-state id="initializeLoginFlow">
    <action-state id="initializeLoginFlow">
        <evaluate expression="LoginAction.initializeFormObject(flowRequestContext)" result="flowScope.loginForm" />
        <transition to="login" />
    </action-state> 
    <view-state id="login" view="login" model="loginForm">
        <transition on="submit" to="section1">
            <evaluate expression="loginAction.performPostLoginProcess(flowScope.loginForm)"></evaluate>
        </transition>
    </view-state>
    <view-state id="section1" view="section1" model="loginForm">
    ...

这样你需要有一个服务类来处理流量需求。希望这可以帮助。

Edit1：在表单proyecto中包含List webFrameworkList。将参考数据更改为

public void referenceData(Proyecto proyecto){
        System.out.println("Setting up list");
        List<String> list=new ArrayList<String>();
        list.add("cb1");
        list.add("cb2");
        list.add("cb3");
        proyecto.setWebFrameworkList(list);
    }

在jsp中：

    td>
        <form:checkboxes items="${webFrameworkList}" path="checkBoxPropertyInModel" /> 
    </td>
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