Question

如何在mule中使用xpath3检查NaN值。

我试图这样做，但没有得到正确的结果

Query queryRef = mDatabase.child("user-tickets").child(userId);
FirebaseRecyclerAdapter<Ticket, TicketViewHolder> adapter = new FirebaseRecyclerAdapter<Ticket, TicketViewHolder>(
            Ticket.class,
            R.layout.item_ticket,
            TicketViewHolder.class,
            queryRef
    ) {
        @Override
        protected void populateViewHolder(TicketViewHolder viewHolder, Ticket model, int position) {
            //want to get Id here for this record
        }
    };

但没有工作

如何检查mule中的NaN值？

Answer 1

尝试使用是或的实例，例如<?xml version="1.0" encoding="UTF-8"?> <data> <total>100</total> </data>

基于进一步测试，使用以下示例：

#[xpath3('//total',payload,'NUMBER').isNaN() ? 0 : xpath3('//total',payload,'NUMBER')]

我们可以使用 isNaN（）方法，因为有效负载是 java.lang.Double 。因此，我们可以使用以下MEL：<flow name="simpleFlow"> <http:listener config-ref="HTTP_Listener_Configuration" path="/" doc:name="HTTP"/> <logger message="#[xpath3('//total',payload,'NUMBER').isNaN() ? 0 : xpath3('//total',payload,'NUMBER')]" level="INFO" doc:name="Logger"/> </flow>

可以通过以下简单流程进行测试：

<data><total>hundred</total></data>

为了测试目的，使用非数字更改总计字段的值，例如：Error: /Users/ali/cream/myApp/platforms/android/gradlew: Command failed with exit code 1 Error output: Exception in thread "main" java.lang.RuntimeException: java.util.zip.ZipException: zip file is empty at org.gradle.wrapper.ExclusiveFileAccessManager.access(ExclusiveFileAccessManager.java:78) at org.gradle.wrapper.Install.createDist(Install.java:47) at org.gradle.wrapper.WrapperExecutor.execute(WrapperExecutor.java:129) at org.gradle.wrapper.GradleWrapperMain.main(GradleWrapperMain.java:48) Caused by: java.util.zip.ZipException: zip file is empty at java.util.zip.ZipFile.open(Native Method) at java.util.zip.ZipFile.<init>(ZipFile.java:215) at java.util.zip.ZipFile.<init>(ZipFile.java:145) at java.util.zip.ZipFile.<init>(ZipFile.java:159) at org.gradle.wrapper.Install.unzip(Install.java:160) at org.gradle.wrapper.Install.access$400(Install.java:29) at org.gradle.wrapper.Install$1.call(Install.java:70) at org.gradle.wrapper.Install$1.call(Install.java:47) at org.gradle.wrapper.ExclusiveFileAccessManager.access(ExclusiveFileAccessManager.java:65) ... 3 more

如何检查骡子中的NaN

1 个答案: