flowExecutionUrl is null in freemarker template

[Leo Ng]

I am now using Spring MVC, Webflow, Security, freemarker to build an application.

When i tried to access a login page in which the webflow access url was written, the error came out and i cannot access to that page.
According to the console, it seems that ${flowExecutionUrl} is null and freemarker cannot display the page.
can anyone give me some help??? thank you.

code is as followed:

login.ftl
<!DOCTYPE> <#import "*/common.ftl" as c/> <@c.page title="ログイン"> <div> <h2> ログイン</h2> <form action="${contextPath}login_processing" method="post"> <fieldset> <legend>ログイン</legend> <table> <tr> <td>ユーザーネーム</td> <td><input type="text" name="j_username"></td> </tr> <tr> <td>パスワード</td> <td><input type="password" name="j_password"></td> </tr> <tr> <td></td> <td><input type="submit" value="発信">    <input type="reset" value="リセット"></td> </tr> <tr> <td></td> <td> <a href="[color=red]${flowExecutionUrl}register[/color]">アカウント登録</a>${"\t"}<a href="${contextPath}forgetPassword">パスワードを忘れますか</a> </td> </tr> </table> </fieldset> </form> </div> </@c.page>


app-ctx.xml
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:mvc="http://www.springframework.org/schema/mvc" xmlns:webflow="http://www.springframework.org/schema/webflow-config" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jpa="http://www.springframework.org/schema/data/jpa" xsi:schemaLocation="http://www.springframework.org/schema/webflow-config http://www.springframework.org/schema/webflow-config/spring-webflow-config-2.4.xsd http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.1.xsd"> <!-- Spring MVC Config --> <mvc:annotation-driven/> <mvc:resources mapping="/resources/**" location="/resources/"/> <context:component-scan base-package="bookshop.controllers"/> <context:component-scan base-package="bookshop.services"/> <context:component-scan base-package="bookshop.test"/> <context:component-scan base-package="bookshop.init"/> <mvc:interceptors> <mvc:interceptor> <mvc:mapping path="/**"/> <bean class="bookshop.interceptors.RandomBooksInterceptor"/> </mvc:interceptor> <mvc:interceptor> <mvc:mapping path="/**"/> <bean class="bookshop.interceptors.GlobalInterceptor"/> </mvc:interceptor> </mvc:interceptors> <!-- FreeMarker Config --> <bean id="freemarkerConfig" class="org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer"> <property name="templateLoaderPath" value="/WEB-INF/views/"/> <property name="defaultEncoding" value="UTF-8" /> </bean> <bean id="viewResolver" class="org.springframework.web.servlet.view.freemarker.FreeMarkerViewResolver"> <property name="cache" value="true"/> <property name="prefix" value=""/> <property name="suffix" value=".ftl"/> <property name="contentType" value="text/html;charset=UTF-8"/> </bean> <!-- Spring Webflow config --> <webflow:flow-executor id="flowExecutor"/> <webflow:flow-registry id="flowRegistry" flow-builder-services="flowBuilderServices"> <webflow:flow-location id="register" path="/WEB-INF/flows/register/register-flow.xml"/> </webflow:flow-registry> <webflow:flow-builder-services id="flowBuilderServices" view-factory-creator="mvcViewFactoryCreator"/> <bean id="mvcViewFactoryCreator" class="org.springframework.webflow.mvc.builder.MvcViewFactoryCreator"> <property name="viewResolvers" ref="viewResolver"/> </bean> <bean class="org.springframework.webflow.mvc.servlet.FlowHandlerAdapter"> <property name="flowExecutor" ref="flowExecutor" /> </bean> <bean class="org.springframework.webflow.mvc.servlet.FlowHandlerMapping"> <property name="flowRegistry" ref="flowRegistry"/> <property name="order" value="0"/> </bean> </beans>

app-ctx-sec.xml

<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:jpa="http://www.springframework.org/schema/data/jpa" xmlns:security="http://www.springframework.org/schema/security" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-3.2.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd http://www.springframework.org/schema/data/jpa http://www.springframework.org/schema/data/jpa/spring-jpa-1.3.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.1.xsd"> <context:component-scan base-package="bookshop.services"/> <security:authentication-manager> <security:authentication-provider user-service-ref="jpaUserDetailsService"> <security:password-encoder hash="md5"/> </security:authentication-provider> </security:authentication-manager> <security:http auto-config="true" use-expressions="true"> <security:intercept-url pattern="/spring/customer/**" access="hasRole('ROLE_CUSTOMER')"/> <security:form-login login-page="/spring/login" login-processing-url="/spring/login_processing" default-target-url="/spring/home"/> <security:logout logout-url="/spring/logout" logout-success-url="/spring/home"/> </security:http> <bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"> <property name="dataSource" ref="dataSource" /> <property name="packagesToScan" value="bookshop.entities" /> <property name="jpaVendorAdapter"> <bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" /> </property> <property name="jpaProperties"> <props> <prop key="hibernate.hbm2ddl.auto">create-drop</prop> <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</prop> </props> </property> </bean> <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName" value="com.mysql.jdbc.Driver" /> <property name="url" value="jdbc:mysql:///test_utf8?useUnicode=yes&characterEncoding=UTF-8" /> <property name="username" value="root" /> <property name="password" value="root" /> </bean> <bean id="transactionManager" class="org.springframework.orm.jpa.JpaTransactionManager"> <property name="entityManagerFactory" ref="entityManagerFactory" /> </bean> <tx:annotation-driven /> <jpa:repositories base-package="bookshop.repositories"/> </beans>

/WEB-INF/flows/register/register-flow.xml

<?xml version="1.0" encoding="UTF-8"?> <flow xmlns="http://www.springframework.org/schema/webflow" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.springframework.org/schema/webflow http://www.springframework.org/schema/webflow/spring-webflow-2.0.xsd"> <on-start> <evaluate expression="registerFlowService.createUser()" result="flowScope.user"/> </on-start> <view-state id="register" model="user"> <transition on="submit" to="confirmRegister"/> <transition on="cancel" to="registerEnd"/> </view-state> <view-state id="confirmRegister"> <transition on="submit" to="registerEnd"> <evaluate expression="registerFlowService.saveUser(user)"/> </transition> <transition on="revise" to="register"/> <transition on="cancel" to="registerEnd"/> </view-state> <end-state id="registerEnd" view="externalRedirect:home"/> </flow>

[Leo Ng]

console error message

an 11, 2015 7:15:18 PM freemarker.log._JDK14LoggerFactory$JDK14Logger error
SEVERE: Error executing FreeMarker template
FreeMarker template error:
The following has evaluated to null or missing:
==> flowExecutionUrl [in template "login.ftl" at line 25, column 36]

----
Tip: If the failing expression is known to be legally refer to something that's null or missing, either specify a default value like myOptionalVar!myDefault, or use <#if myOptionalVar??>when-present<#else>when-missing</#if>. (These only cover the last step of the expression; to cover the whole expression, use parenthesis: (myOptionalVar.foo)!myDefault, (myOptionalVar.foo)??
----

----
FTL stack trace ("~" means nesting-related):
- Failed at: ${flowExecutionUrl} [in template "login.ftl" at line 25, column 34]
~ Reached through: #nested [in template "*/common.ftl" in macro "page" at line 74, column 1]
~ Reached through: @c.page title="ログイン" [in template "login.ftl" at line 3, column 1]
----

Java stack trace (for programmers):
----
freemarker.core.InvalidReferenceException: [... Exception message was already printed; see it above ...]
at freemarker.core.InvalidReferenceException.getInstance(InvalidReferenceException.java:108)
at freemarker.core.EvalUtil.coerceModelToString(EvalUtil.java:346)
at freemarker.core.Expression.evalAndCoerceToString(Expression.java:80)
at freemarker.core.DollarVariable.accept(DollarVariable.java:40)
at freemarker.core.Environment.visit(Environment.java:257)
at freemarker.core.MixedContent.accept(MixedContent.java:57)
at freemarker.core.Environment.visit(Environment.java:257)
at freemarker.core.Environment.visit(Environment.java:479)
at freemarker.core.BodyInstruction.accept(BodyInstruction.java:56)
at freemarker.core.Environment.visit(Environment.java:257)
at freemarker.core.MixedContent.accept(MixedContent.java:57)
at freemarker.core.Environment.visit(Environment.java:257)
at freemarker.core.Macro$Context.runMacro(Macro.java:173)
at freemarker.core.Environment.visit(Environment.java:686)
at freemarker.core.UnifiedCall.accept(UnifiedCall.java:80)
at freemarker.core.Environment.visit(Environment.java:257)
at freemarker.core.MixedContent.accept(MixedContent.java:57)
at freemarker.core.Environment.visit(Environment.java:257)
at freemarker.core.Environment.process(Environment.java:235)
at freemarker.template.Template.process(Template.java:262)
at org.springframework.web.servlet.view.freemarker.FreeMarkerView.processTemplate(FreeMarkerView.java:366)
at org.springframework.web.servlet.view.freemarker.FreeMarkerView.doRender(FreeMarkerView.java:283)
at org.springframework.web.servlet.view.freemarker.FreeMarkerView.renderMergedTemplateModel(FreeMarkerView.java:233)
at org.springframework.web.servlet.view.AbstractTemplateView.renderMergedOutputModel(AbstractTemplateView.java:167)
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:303)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1228)
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1011)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:955)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:877)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:966)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:857)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:842)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:118)
at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:84)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:113)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:103)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:113)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:154)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:45)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.www.BasicAuthenticationFilter.doFilter(BasicAuthenticationFilter.java:150)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:199)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:110)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:50)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:87)
at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342)
at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:192)
at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160)
at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:344)
at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:261)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:503)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:136)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:526)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1078)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:655)
at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1566)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1523)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)

19:15:18.309 [http-nio-8080-exec-9] DEBUG o.s.s.w.c.HttpSessionSecurityContextRepository - SecurityContext is empty or contents are anonymous - context will not be stored in HttpSession.
19:15:18.310 [http-nio-8080-exec-9] DEBUG o.s.web.servlet.DispatcherServlet - Error rendering view [org.springframework.web.servlet.view.freemarker.FreeMarkerView: name 'login'; URL [login.ftl]] in DispatcherServlet with name 'spring'
freemarker.core.InvalidReferenceException: The following has evaluated to null or missing:
==> flowExecutionUrl [in template "login.ftl" at line 25, column 36]

----
Tip: If the failing expression is known to be legally refer to something that's null or missing, either specify a default value like myOptionalVar!myDefault, or use <#if myOptionalVar??>when-present<#else>when-missing</#if>. (These only cover the last step of the expression; to cover the whole expression, use parenthesis: (myOptionalVar.foo)!myDefault, (myOptionalVar.foo)??
----

----

[Leo Ng]

solved.

After numerous tests, i found out how to get into the webflow with freemarker template.
i dunno whether it is a good approach or not. Just make a reference in here and hope it can help someone who will face the same problem in the future.

the xml configuration is the same but the the webflow's view files must be placed into where the views' folder are.
in this case, they must be put into here: /WEB-INF/views/ (please refer to the previous xml configuration).
By the way, the webflow' xml config file can be put into file folders within the classpath and its path must be matched with the Flow Registry one.

Then, ${flowExecutionUrl} in a page which is the entry to the first view-state should be revised to: /your_context_path/your_flow_id.

just like this:

<!DOCTYPE> <#import "*/common.ftl" as c/> <@c.page title="ログイン"> <div> <h2> ログイン</h2> <form action="${contextPath}login_processing" method="post"> <fieldset> <legend>ログイン</legend> <table> <tr> <td>ユーザーネーム</td> <td><input type="text" name="j_username"></td> </tr> <tr> <td>パスワード</td> <td><input type="password" name="j_password"></td> </tr> <tr> <td></td> <td><input type="submit" value="発信">    <input type="reset" value="リセット"></td> </tr> <tr> <td></td> <td> <a href="${contextPath}register">アカウント登録</a>${"\t"}<a href="${contextPath}forgetPassword">パスワードを忘れますか</a> </td> </tr> </table> </fieldset> </form> </div> </@c.page>

${contextPath}register"

${contextPath}: it has been assigned in the server side, not a SpEl.
register: flow id.

Then, you can be navigated into the webflow with FreeMarker ^_^