Question

我有一个名为CampaignMaint.java的Servlet，它带有一个doGet和一个doPost以及一个名为JCampaignMaint.jsp的JSP。在输入URL / CampaignMaint？campaign = Treasury时，doGet将数据构建到一个数组中并执行：

Request.setAttribute("OrgContacts", contacts);
RequestDispatcher rd = request.getRequestDispatcher("JCampaignMaint.jsp");
rd.forward(request,response);

然后，

JCampaignMaint.jsp构建一个包含一些可修改字段的表，如下所示：

<form action="CampaignMaint" method="post">
<c:forEach var="OrgContact" items="${OrgContacts}">
<tr>
<td>${OrgContact.orgName}</td>
<td>${OrgContact.orgTitle}</td>
<td><input type="number" name=${OrgContact.orgJoinName} value=${OrgContact.orgInfluence} min="1" max="5"</td>
<td><input type="number" name=${OrgContact.orgJoinName}  value=${OrgContact.orgSupport} min="1" max="5"</td>
<td><input type="number" name=${OrgContact.orgJoinName}  value=${OrgContact.orgEngagement} min="1" max="5"</td>
</tr>
</c:forEach>

<input type="submit" value="Submit">
</form>

单击“提交”按钮，HTTP Post将发送到服务器并由CampaignMaints goPost方法处理，其中读取表单以更新数据库。屏幕现在为空白，带有URL / SalesPoliticalMapping / CampaignMaint。

我想要的是提交doPost时更新数据库，但我的屏幕与显示的表格（或重建/重新显示）以及原始网址/ CampaignMaint？campaign = Treasury保持一致。然后，我希望能够进行进一步的更新和提交。

添加

时的GlassFish堆栈跟踪

response.sendRedirect("/CampaignMaint?campaign=Treasury");

警告：StandardWrapperValve [CampaignMaint]：servlet的Servlet.service（）CampaignMaint抛出异常 java.lang.IllegalStateException 在org.apache.catalina.connector.ResponseFacade.sendRedirect（ResponseFacade.java:518）在com.mycompany.salespoliticalmapping.controller.CampaignMaint.doPost（CampaignMaint.java:196）在javax.servlet.http.HttpServlet.service（HttpServlet.java:707）在javax.servlet.http.HttpServlet.service（HttpServlet.java:790）在org.apache.catalina.core.StandardWrapper.service（StandardWrapper.java:1682）在org.apache.catalina.core.StandardWrapperValve.invoke（StandardWrapperValve.java:318） at org.apache.catalina.core.StandardContextValve.invoke（StandardContextValve.java:160）在org.apache.catalina.core.StandardPipeline.doInvoke（StandardPipeline.java:734）在org.apache.catalina.core.StandardPipeline.invoke（StandardPipeline.java:673）在com.sun.enterprise.web.WebPipeline.invoke（WebPipeline.java:99）在org.apache.catalina.core.StandardHostValve.invoke（StandardHostValve.java:174）在org.apache.catalina.connector.CoyoteAdapter.doService（CoyoteAdapter.java:357）在org.apache.catalina.connector.CoyoteAdapter.service（CoyoteAdapter.java:260）在com.sun.enterprise.v3.services.impl.ContainerMapper.service（ContainerMapper.java:188）在org.glassfish.grizzly.http.server.HttpHandler.runService（HttpHandler.java:191）在org.glassfish.grizzly.http.server.HttpHandler.doHandle（HttpHandler.java:168）在org.glassfish.grizzly.http.server.HttpServerFilter.handleRead（HttpServerFilter.java:189）在org.glassfish.grizzly.filterchain.ExecutorResolver $ 9.execute（ExecutorResolver.java:119）在org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter（DefaultFilterChain.java:288）在org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart（DefaultFilterChain.java:206）在org.glassfish.grizzly.filterchain.DefaultFilterChain.execute（DefaultFilterChain.java:136）在org.glassfish.grizzly.filterchain.DefaultFilterChain.process（DefaultFilterChain.java:114）在org.glassfish.grizzly.ProcessorExecutor.execute（ProcessorExecutor.java:77）在org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent（TCPNIOTransport.java:838）在org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent（AbstractIOStrategy.java:113）在org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0（WorkerThreadIOStrategy.java:115）在org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access $ 100（WorkerThreadIOStrategy.java:55）在org.glassfish.grizzly.strategies.WorkerThreadIOStrategy $ WorkerThreadRunnable.run（WorkerThreadIOStrategy.java:135）在org.glassfish.grizzly.threadpool.AbstractThreadPool $ Worker.doWork（AbstractThreadPool.java:564）在org.glassfish.grizzly.threadpool.AbstractThreadPool $ Worker.run（AbstractThreadPool.java:544）在java.lang.Thread.run（Thread.java:745）

Answer 1

您的doPost方法可以重定向到生成视图的方法，而不是转发到jsp：

response.sendRedirect("/yourwebappname/CampaignMaint?campaign=Treasury");

这样您就不必在post方法中重复显示逻辑，您将看到使用提交结果更新的视图。（您将看到屏幕刷新，因为这是一个新的GET请求。）

此技术还避免了重复的表单提交，称为Post/redirect/get pattern。

在发布到Servlet之后重新显示JSP

1 个答案: