Liferay表单功能Bug：无法创建超过28个项的表单

问题概述 #

使用Liferay CE 7.4.32时，创建表单添加超过28个字段后无法保存，触发如下错误，且保存时会跳转到表单列表导致新增内容丢失：

2022-09-05 11:31:24.685 ERROR [http-nio-8080-exec-1][PortletServlet:117] null
javax.portlet.PortletException: java.lang.IllegalStateException: The property "serializedFormContext" is required
    at com.liferay.portal.kernel.portlet.bridges.mvc.BaseTransactionalMVCActionCommand.processAction(BaseTransactionalMVCActionCommand.java:58) ~[portal-kernel.jar:?]
    at com.liferay.portal.kernel.portlet.bridges.mvc.MVCPortlet.callActionMethod(MVCPortlet.java:402) ~[portal-kernel.jar:?]
    at com.liferay.portal.kernel.portlet.LiferayPortlet.processAction(LiferayPortlet.java:82) ~[portal-kernel.jar:?]
    at com.liferay.portal.kernel.portlet.bridges.mvc.MVCPortlet.processAction(MVCPortlet.java:256) ~[portal-kernel.jar:?]
    at com.liferay.portlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:77) ~[portal-impl.jar:?]
    at com.liferay.portal.kernel.portlet.PortletFilterUtil.doFilter(PortletFilterUtil.java:50) ~[portal-kernel.jar:?]
    at com.liferay.portal.kernel.servlet.PortletServlet.service(PortletServlet.java:113) ~[portal-kernel.jar:?]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:764) ~[servlet-api.jar:4.0.FR]
    at org.eclipse.equinox.http.servlet.internal.registration.EndpointRegistration.service(EndpointRegistration.java:153) ~[?:?]
    at org.eclipse.equinox.http.servlet.internal.servlet.ResponseStateHandler.processRequest(ResponseStateHandler.java:62) ~[?:?]
    at org.eclipse.equinox.http.servlet.internal.context.DispatchTargets.doDispatch(DispatchTargets.java:120) ~[?:?]
    at org.eclipse.equinox.http.servlet.internal.servlet.RequestDispatcherAdaptor.include(RequestDispatcherAdaptor.java:48) ~[?:?]
....
    at java.lang.Thread.run(Thread.java:748) [?:1.8.0_301]
Caused by: java.lang.IllegalStateException: The property "serializedFormContext" is required
    at com.liferay.dynamic.data.mapping.form.builder.internal.context.DDMFormContextToDDMForm.deserialize(DDMFormContextToDDMForm.java:77) ~[?:?]
    at com.liferay.dynamic.data.mapping.form.builder.internal.context.DDMFormContextToDDMForm.deserialize(DDMFormContextToDDMForm.java:59) ~[?:?]
    at com.liferay.dynamic.data.mapping.form.web.internal.portlet.action.helper.SaveFormInstanceMVCCommandHelper._getDDMForm(SaveFormInstanceMVCCommandHelper.java:222) ~[bundleFile:?]
    at com.liferay.dynamic.data.mapping.form.web.internal.portlet.action.helper.SaveFormInstanceMVCCommandHelper._updateFormInstance(SaveFormInstanceMVCCommandHelper.java:340) ~[bundleFile:?]
    at com.liferay.dynamic.data.mapping.form.web.internal.portlet.action.helper.SaveFormInstanceMVCCommandHelper.saveFormInstance(SaveFormInstanceMVCCommandHelper.java:125) ~[bundleFile:?]
    at com.liferay.dynamic.data.mapping.form.web.internal.portlet.action.SaveFormInstanceMVCActionCommand.doService(SaveFormInstanceMVCActionCommand.java:57) ~[bundleFile:?]
    at com.liferay.dynamic.data.mapping.form.web.internal.portlet.action.SaveFormInstanceMVCActionCommand.doTransactionalCommand(SaveFormInstanceMVCActionCommand.java:84) ~[bundleFile:?]
    at com.liferay.portal.kernel.portlet.bridges.mvc.BaseTransactionalMVCActionCommand$1.call(BaseTransactionalMVCActionCommand.java:44) ~[portal-kernel.jar:?]
    at com.liferay.portal.kernel.portlet.bridges.mvc.BaseTransactionalMVCActionCommand$1.call(BaseTransactionalMVCActionCommand.java:40) ~[portal-kernel.jar:?]
    at com.liferay.portal.spring.transaction.BaseTransactionExecutor.execute(BaseTransactionExecutor.java:37) ~[portal-impl.jar:?]
    at com.liferay.portal.spring.transaction.TransactionInvokerImpl.invoke(TransactionInvokerImpl.java:39) ~[portal-impl.jar:?]
    at com.liferay.portal.kernel.transaction.TransactionInvokerUtil.invoke(TransactionInvokerUtil.java:28) ~[portal-kernel.jar:?]

问题根源 #

这个错误的核心原因是Tomcat默认的请求参数个数限制（默认maxParameterCount=256）。当表单字段超过28个时，每个字段会生成多个关联参数，总参数数超过Tomcat的默认限制，导致serializedFormContext参数被截断丢失，后端验证时找不到该必填参数，从而抛出错误。

修复方案 #

1. 修改Tomcat参数限制配置 #

• 找到Liferay所用Tomcat的conf/server.xml文件
• 在Connector标签中添加maxParameterCount属性，设置一个足够大的值（比如1000，可根据实际表单字段数调整）：

<Connector port="8080" protocol="HTTP/1.1"
           connectionTimeout="20000"
           redirectPort="8443"
           maxParameterCount="1000" />

• 重启Tomcat服务，配置生效后即可添加超过28个字段的表单。

2. 临时规避方案（无需重启服务器） #

• 将大表单拆分为多个子表单，通过业务流程或关联字段整合数据
• 使用自定义开发的表单替代默认的DDM表单构建器，绕过前端参数提交限制

内容的提问来源于stack exchange，提问作者Danielly Sorato