在 Java Spring 窗体中发布多行

Question

我将数据库中的多行(每一行代表我们的参数)填充到我的表单中。form类有一个我们的参数列表。我能够填充如下表格:填充的表格

然而，当提交时，我得到一个空指针异常:由于某种原因，modelAttribute没有返回到控制器post方法(即save)

位于un.ac.ucl.isd.our.web.controller.SettingsFormController.save（SettingsFormControler.java:71）处的java.lang.NullPointerException位于sun.rereflect.NativeMethodAccessorImpl.invoke0（本机方法）位于sun.reReflect.NativeMethod AccessorImpl.invoke（未知源）位于sun/rereflect.DelegatingMethodAccessorImpl.invokeorg.springframework.web.bind.annotation.support.HandlerMethodInvoker.doInvokeMethod（HandlerMethodInvoker.java:421），位于org.springfframework.web.bind.ann批注.support.HandlerMethod Invoker.invokeHandlerMethod（HandlerSethodInvoker.java：136），位于：org.springframework.web.servlet.DispatcherServlet.doDispatcher（DispatcherServlets.java：875）位于org.springfframework.web.servlet.DisptcherServlet.doService（Dispatcher servlet.java：807）位于org.springframework.web.servlet.FrameworkServlet.prrocessRequest（FrameworkServlet.java:571），位于org.springframework.web.servlet.FrameworkServlet.doPost（FrameworkServlet.java:511），位于java.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:290）org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:206），位于org.apache.cacatalina.core.StandardWrapperValve.invoke（StandardWrapperValve.java:233），位于org.apache.catalina/core.Standard ContextValve.involke（StandardContextValve.java:191）（ErrorReportValve.java:103）位于org.apache.catalina.core.StandardEnginealve.invoke（StandardEnginealve.java:109），位于org.apache.cotalina.connecter.CoyoteAdapter.service（CoyoteAdapter.java:293），位于org/apache.coyote.http11.Http11Processor.processe（Http11Processor.java:861），位于org apache.coyoote.Http11Protocol$Http11ConnectionHandler.process（Http11Protocol.java:606）org.apache.tomcat.util.net.JIoEndpoint$Worker.run（JIoEndpoint.java:489）位于java.lang.Thread.run（未知源）知道为什么吗？

我使用的是springframework v2.5.6……我尝试过实现（如何使用javaspringframe将web表单中的多行插入到数据库中），但它对我来说不起作用。

表单类：

package uk.ac.ucl.isd.our.web.controller.command;

import java.util.List;
import uk.ac.ucl.isd.our.access.domain.OurParameter;

public class SettingsForm {

    private List<OurParameter> params;

    public List<OurParameter> getParams() {
        return params;
    }

    public void setParams(List<OurParameter> params) {
        this.params = params;
    }

}

OurParameter类：

package uk.ac.ucl.isd.our.access.domain;

import uk.ac.ucl.upi.AppParameter;

public class OurParameter {
    private String app;
    private String description;
    private String enabled;
    private String grp;
    private String name;
    private String value;

    private String paramValue;
    private String paramType;
    private String paramFormat;

    public String getApp() {
        return app;
    }
    public void setApp(String app) {
        this.app = app;
    }
    public String getDescription() {
        return description;
    }
    public void setDescription(String description) {
        this.description = description;
    }
    public String getEnabled() {
        return enabled;
    }
    public void setEnabled(String enabled) {
        this.enabled = enabled;
    }
    public String getGrp() {
        return grp;
    }
    public void setGrp(String grp) {
        this.grp = grp;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getValue() {
        return value;
    }
    public void setValue(String value) {
        this.value = value;
    }
    public String getParamValue() {
        return paramValue;
    }


    public void setParamValue(String paramValue) {
        try {
            this.paramValue = AppParameter.getValue(getValue());
        } catch (Exception e) {}
    }
    public String getParamType() {
        return paramType;
    }
    public void setParamType(String paramType) {
        try {
            this.paramType = AppParameter.getType(getValue());
        } catch (Exception e) {}
    }
    public String getParamFormat() {
        return paramFormat;
    }
    public void setParamFormat(String paramFormat) {
        try {
            this.paramFormat = AppParameter.getFormat(getValue());
        } catch (Exception e) {}
    }

}

控制器:

package uk.ac.ucl.isd.our.web.controller;



import java.util.List;

import org.apache.log4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.servlet.ModelAndView;

import uk.ac.ucl.isd.our.access.domain.OurParameter;
import uk.ac.ucl.isd.our.service.UPIService;
import uk.ac.ucl.isd.our.web.controller.command.SettingsForm;

/**
 * 
 * 
 * @author Mo
 * 
 * 
 */

@Controller
public class SettingsFormController {


    final static Logger logger = Logger.getLogger(SettingsFormController.class);

    private UPIService upiService;



    @Autowired
    public void setUpiService(UPIService upiService)
    {
        this.upiService = upiService;
    }

    public SettingsFormController()
    {

    }

    @RequestMapping(value = "/settings.do", method = RequestMethod.GET) 
    public ModelAndView get() {
            SettingsForm settingsForm = new SettingsForm();
                List<OurParameter> ourparams = upiService.getAppParamsInfo("OUR");
                settingsForm.setParams(ourparams);
                return new ModelAndView("settingsForm","settingsForm", settingsForm);
    }

    @RequestMapping(value = "/settings.do", method = RequestMethod.POST)
    public ModelAndView save(@ModelAttribute("settingsForm") SettingsForm settingsForm) {
        for (OurParameter oPP: settingsForm.getParams()){
            logger.info("Momo Says the posted thingy is: "+oPP.getValue());
            logger.info("Momo Says the posted thingy is: "+oPP.getName());
        }
            //return null;
        return new ModelAndView("settingsForm");
    }

}

最后是 JSP：

<%@taglib uri="http://www.springframework.org/tags" prefix="spring"%>
<%@taglib uri="http://www.springframework.org/tags/form" prefix="form"%>
<%@taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<html>
<head>
    <title>Spring 3 MVC Multipe Row Submit - viralpatel.net</title>
</head>
<body>

<h2>Spring MVC Multiple Row Form Submit example</h2>
<form:form method="post" modelAttribute="settingsForm">
    <table>
    <tr>
        <th>No.</th>
        <th>Name</th>
    </tr>
    <c:forEach items="${settingsForm.params}" var="setting" varStatus="pStatus">
        <tr>
            <td align="center">${status.count}</td>
            <td>
            <input name="settingsForm.params[${status.index}].app" value="${setting.app}"/>
            <input name="settingsForm.params[${status.index}].description" value="${setting.description}"/>
            <input name="settingsForm.params[${status.index}].enabled" value="${setting.enabled}"/>
            <input name="settingsForm.params[${status.index}].grp" value="${setting.grp}"/>
            <input name="settingsForm.params[${status.index}].value" value="${setting.value}"/>
            <input name="settingsForm.params[${status.index}].paramValue" value="${setting.paramValue}"/>
            <input name="settingsForm.params[${status.index}].paramType" value="${setting.paramType}"/>
            <input name="settingsForm.params[${status.index}].paramFormat" value="${setting.paramFormat}"/>
        </tr>
    </c:forEach>
</table>    
<br/>
<input type="submit" value="Save" />

</form:form>
</body>
</html>

Answer 1

在你引用的例子中，你不会用:

<代码>

你不先试试这个吗？