【发布时间】：2015-09-03 14:28:47
【问题描述】：
每次接触 web 流时我都感到痛苦，我认为在 grails 的世界中事情可能会像 Spring MVC 那样更简单和易于理解，但似乎并非如此。
我有一个简单的情况，我想在显示 Web 流的第一页时使用流范围内已经预填充的命令对象启动 Web 流。命令对象基本上是从域对象中保存值的副本
这是我的命令对象：
@grails.validation.Validateable(nullable=false)
class PatientEditFlowCommand implements Serializable{
StepOneCommand stepOneCommand
PatientEditFlowCommand(Patient patient){
stepOneCommand = new StepOneCommand(
patientName : "${patient.appUser?.firstName} ${patient.appUser?.lastName}",
patientDoctorId : patient.doctor?.id,
patientNurseId : patient.nurse?.id,
patientStartDate : patient.startDate,
patientEndDate : patient.endDate,
patientDrugRegimeId: patient.regime?.id
)
}
static constraints = {
}
}
@grails.validation.Validateable(nullable=false)
class StepOneCommand implements Serializable{
String patientName //wont be editable
Long patientDoctorId //user id of assigned doctor
Long patientNurseId //user id of assigned doctor
Date patientStartDate
Date patientEndDate
Long patientDrugRegimeId
static constraints = {
patientDoctorId(nullable: false)
patientNurseId(nullable: false)
patientStartDate(nullable: false)
patientEndDate(nullable: false)
patientDrugRegimeId(nullable: false)
}
}
@grails.validation.Validateable(nullable=false)
class StepTwoCommand implements Serializable{
static constraints = {
}
}
这是我在控制器中的流程：
def newEditFlow = {
init {
//start the flow by transferring domain obj into a command object
action {
Patient patient = Patient.get(params.id)
[patientEditFlowCommand:new PatientEditFlowCommand(patient)]
success()
}
on ("success"){
}.to "stepOne"
}
stepOne{
on("next") {
}.to("stepTwo")
on("cancel").to("finish")
}
stepTwo{
on("next") {
}.to("stepThree")
on("previous").to("stepOne")
}
stepThree{
on("next") {
}.to("stepFour")
on("previous").to("stepTwo")
}
stepFour{
on("next") {
}.to("finish")
on("previous").to("stepThree")
}
finish{
redirect(controller:'patient',action: "list")
}
}
但是当我导航到第一个转换时，我得到了这个
错误 500：内部服务器错误
URI /ivfportal/patient/newEdit/3 班级 java.lang.NullPointerException 信息 空值 GrailsFlowExecutorImpl.java的第74行左右
71: }72:73: 尝试 {74: return super.resumeExecution(flowExecutionKey, context);75: }76: catch (FlowExecutionRestorationFailureException e) {77: if (e.getCause() instanceof SnapshotUnmarshalException) { GrailsFlowHandlerAdapter.java的第53行左右
50: request.setAttribute(GrailsApplicationAttributes.CONTROLLER, controllerInstance);51: }52:53: return super.handle(request, response, handler);54: }55:56: public void setGrailsApplication(GrailsApplication grailsApplication) { PageFragmentCachingFilter.java 的第 189 行左右
186: if (method == null) {187: log.debug("No cacheable method found for {}:{} {}",188: new Object[] { request.getMethod(), request.getRequestURI (), getContext() });189: chain.doFilter(request, response);190: return;191: }192: Collection cacheOperations = cacheOperationSource.getCacheOperations( AbstractFilter.java 的第 63 行左右
60: try {61: // 为 RequestDispatcher 转发设置 NO_FILTER 以避免双重 gzipping62: if (filterNotDisabled(request)) {63: doFilter(request, response, chain);64: }65: else {66: chain .doFilter(req, res); DevModeSanityFilter.groovy 的第 45 行左右
42: response.contentType = "text/html"43: response.writer
50:51: applyAnonymousForThisRequest((HttpServletRequest)req);52:53: chain.doFilter(req, res);54: }55:56: protected void applyAnonymousForThisRequest(HttpServletRequest request) { RestAuthenticationFilter.groovy 的第 139 行左右
有人知道我哪里出错了吗？在 Grails 中是否有一种更简单但仍然整洁的方法来通过多页面流收集数据？
【问题讨论】：
标签： grails web spring-webflow flow