Question

我有一个MapReduce程序，可以从文件夹及其子文件夹中递归读取文件。我编写了一个自定义文件输入格式类，使得isSplitable为false，以确保一个完整文件只转到一个映射器并逐行读取文件。现在，我正在搜索模式，如果找到匹配，我不想继续，并希望跳过当前文件的执行。我们如何在mapper类中实现这一目标？

Answer 1

您只需重新实现run方法即可。例如像这样，使用布尔字段直接短路到清理阶段。

Option Explicit

Sub Test()

    Dim i As Integer
    Dim ws As Worksheet
    Dim rng As Range

    'set sheet1 traking value for i = to lookup on sheet2
    Set ws = ThisWorkbook.Worksheets("Sheet1")

    'loop through indexes
    For i = 1 To 6
        Set rng = ws.Columns("A:A").Find(What:=i)
        rng.Offset(0, 3).Value = rng.Offset(0, 3) & AddToTraking(i)
    Next i

End Sub

Function AddToTraking(ByVal num As Integer) As String
    Dim ws As Worksheet
    Dim rng As Range
    Dim str As String

    Set ws = ThisWorkbook.Worksheets("Sheet2")
    Set rng = ws.Columns("A:A").Find(What:=num)
    If Not rng Is Nothing Then
        str = rng.Offset(0, 2).Value
    Else
        str = ""
    End If

    AddToTraking = str

End Function

如何从MapReduce中的Mapper跳过当前处理文件

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