Question

让我们假设我有两个由

检索的日期（A和B）

:calendar.universal_time(), e.g. {{2016, 5, 5}, {13, 17, 29}}

我需要确定日期A是否比日期B大30天（或更多）。

我怎样才能在Elixir中做到？

Answer 1

您可以使用:calendar.time_to_gregorian_days。

iex(1)> {date, time} = {{2016, 5, 5}, {13, 17, 29}}
{{2016, 5, 5}, {13, 17, 29}}
iex(2)> :calendar.date_to_gregorian_days(date)
736454

对两个日期执行此操作并减去值并检查该值是否大于30.

Answer 2

您可以在两个日期时间调用:calendar.datetime_to_gregorian_seconds/1，减去结果并将结果与30 * 24 * 60 * 60（30天内的秒数）进行比较：

defmodule A do
  def thirty_days_apart(low, high) do
    min = 30 * 24 * 60 * 60
    (:calendar.datetime_to_gregorian_seconds(high) -
     :calendar.datetime_to_gregorian_seconds(low)) >= min
  end
end

IO.inspect A.thirty_days_apart({{2000, 1, 1}, {0, 0, 0}}, {{2000, 2, 1}, {0, 0, 0}})
IO.inspect A.thirty_days_apart({{2000, 2, 1}, {0, 0, 0}}, {{2000, 3, 1}, {0, 0, 0}})

打印

true
false

Answer 3

您可以使用Timex：

<?xml version="1.0" encoding="UTF-8"?>
    <beans:beans xmlns="http://www.springframework.org/schema/mvc"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xmlns:beans="http://www.springframework.org/schema/beans"
        xmlns:context="http://www.springframework.org/schema/context"
        xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
            http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
            http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">

        <!-- DispatcherServlet Context: defines this servlet's request-processing infrastructure -->



        <!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources directory -->
        <resources mapping="/resources/**" location="/resources/" />

        <!-- Resolves views selected for rendering by @Controllers to .jsp resources in the /WEB-INF/views directory -->
        <beans:bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
            <beans:property name="prefix" value="/WEB-INF/views/" />
            <beans:property name="suffix" value=".jsp" />
        </beans:bean>


        <!-- Enables the Spring MVC @Controller programming model -->
        <annotation-driven />


        <context:component-scan base-package="com.ujjwol.controller"/>
        <context:component-scan base-package="com.ujjwol.serviceImp"></context:component-scan>
       <context:component-scan base-package="com.ujjwol.daoImp"></context:component-scan>
</beans:beans>








  May 05, 2016 9:21:14 PM org.apache.catalina.core.StandardWrapperValve invoke
    SEVERE: Servlet.service() for servlet [appServlet] in context with path [/demo] threw exception [Request processing failed; nested exception is java.lang.NullPointerException] with root cause
    java.lang.NullPointerException
        at com.ujjwol.daoImp.UserDaoImp.createUser(UserDaoImp.java:23)
        at com.ujjwol.serviceImp.UserServiceImp.createUser(UserServiceImp.java:23)
        at com.ujjwol.controller.UserController.saveUser(UserController.java:24)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:606)
        at org.springframework.web.method.support.InvocableHandlerMethod.invoke(InvocableHandlerMethod.java:214)
        at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:132)
        at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:104)
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandleMethod(RequestMappingHandlerAdapter.java:749)
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:690)
        at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:83)
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:945)
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876)
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
        at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:618)
        at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:725)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:291)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:239)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:106)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:142)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)
        at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:610)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:88)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:537)
        at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1085)
        at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:658)
        at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:222)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1556)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1513)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.lang.Thread.run(Thread.java:745)

比较Elixir的两个日期

3 个答案: