json - 无法将类为 'parseDate' 的对象 'java.lang.String' 转换为 grails 中的类 'java.util.Date'

Question

我是 grails 的新手，想学习，在此代码中，我正在创建 jsonDate 并在创建方法中使用。当我从 SoapUi 发送数据时，出现类似 Cannot cast object '13/01/2014' with class 'java.lang.String' to class 'java.util.Date' 的错误。

class RequestMainController {
    static scaffold = true
    static allowedMethods = [save: "POST", updat``e: "PUT", delete: "DELETE"]
    def index(Integer max) {
        params.max = Math.min(max ?: 10, 100)
        respond RequestMain.list(params), model:[requestMainInstanceCount: RequestMain.count()]
    }

    SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
    //System.out.println(Current Date  + sdf.format(new Date());
    String mydate = "01-08-2011";
    Date parseDate = sdf.parse(mydate);

    def slurper = new JsonSlurper()
    def requestMain = slurper.parseText('{"milestoneSequenceNumber":"111","recordStartDate":"13/01/2014",
                                          "recordEndDate":"13/01/2014","application":"app","applicationType":"A""}');

    def create(){
        //def jsonObject = grails.converters.JSON.parse(requestMain) 
        def milestoneSequenceNumber = requestMain.milestoneSequenceNumber
        def recStartDate = requestMain.recordStartDate
        def recEndDate = requestMain.recordEndDate
        def application = requestMain.application
        def applicationType = requestMain.applicationType
        System.out.println(" MILESTONE_SEQ_NO = $milestoneSequenceNumber,REC_START_DATE = $recStartDate, REC_START_DATE=$recEndDate,APPLICATION=$application,APPL_TYPE=$applicationType)

        render(view:"create", action:"save")
    }

    def save() {
        RequestMain requestMain1 = new RequestMain()

        requestMain1.mimeNo = requestMain.milestoneSequenceNumber
        requestMain1.recStartDate = requestMain.recordStartDate
        requestMain1.recEndDate = requestMain.recordEndDate
        requestMain1.application = requestMain.application
        SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");
        String mydate = "01-08-2011";
        Date parseDate = sdf.parse(mydate);
        requestMain1.save()
        render "Success!"
    }
}

Answer 1

实际上，您在在线保存中遇到的错误-

 Date parseDate = sdf.parse(mydate);

是因为您不能将日期字符串直接更改为 SimpleDateFormat。因此，您需要将其更改为 Date 类对象。

String mydate = "01-08-2011";
def parsedDate = Date.parse("yyyy-MM-dd", mydate);
Date parseDate = sdf.parse(parsedDate);

虽然这样做也是不合逻辑的，因为 parsedDate 已经是 Date 类的对象，因此您无需再次转换它。

如果您出于任何特定原因不使用 SimpleDateFormat，您始终可以使用以下方法-

1. 将日期更改为特定格式的字符串-

   def myStringDate = dateObj.format("yyyy-MM-dd");
   

2. 将字符串更改为日期

   def myDate = Date.parse("yyyy-MM-dd", myStringDate);
   

这些方法更加 GROOVYish，将使您的工作变得轻松。

可以使用 java 文档中指定的格式制作这些传递日期格式- http://docs.oracle.com/javase/1.5.0/docs/api/java/text/SimpleDateFormat.html