错误：使用替代方法写入重载方法值：

Question

我正在尝试读取一个固定宽度的文件并将其写为文本文件，下面是代码。字段的输入文件布局长度(4,10,3,5,3,1,1,5,7)

094482018-07-10 022 14012 000 0 30000A 002290{

059412018-07-10 022 14013 000 0 30000A 002290{

015172018-07-10 046 17502 000 0 30000A 001699I

scala> val inputdata = scala.io.Source.fromFile("/C:/Users/rrrrrr/Desktop/datas
tage/inputdata.txt")
inputdata: scala.io.BufferedSource = non-empty iterator

scala> val lines = inputdata.getLines
lines: Iterator[String] = non-empty iterator

scala> val matched=lines.map(l=>(l.substring(0,5).trim(),l.substring(5,5).trim()
))
matched: Iterator[(String, String)] = non-empty iterator

scala> val outputdata= new File("/C:/Users/rkumar0/Desktop/folder/output_N4.txt"
)
outputdata: java.io.File = C:\Users\rrrrrrr\Desktop\folder\output_N4.txt

scala> val writer= new BufferedWriter(new FileWriter(outputdata))
writer: java.io.BufferedWriter = java.io.BufferedWriter@759c0c14

scala> matched.foreach{line =>
     | writer.write(line)
     | writer.newLine()
     | }
<console>:19: error: overloaded method value write with alternatives:
  (x$1: Int)Unit <and>
  (x$1: String)Unit <and>
  (x$1: Array[Char])Unit
 cannot be applied to ((String, String))
       writer.write(line)
              ^

scala>

我的输出文件创建为空。

Answer 1

错误消息告诉您write 采用Int 或String 或Array[Char]，但您传递给它的是(String, String) 的2 元组。您需要将Int、String 或Array[Char] 传递给它，而不是(String, String) 的二元组。

Answer 2

您的行的类型为(String, String)，但要编写它们，您应该使用toString() 方法将它们转换为String，并且不要忘记在编写后调用flush() 和close()：

matched.foreach(line => {
  writer.write(line.toString)
  writer.newLine()
})
writer.flush()
writer.close()

更新的解决方案（基于输入数据）

import java.io.{BufferedWriter, File, FileWriter}
import java.time.LocalDate

import scala.util.{Failure, Success, Try}

val inputData = scala.io.Source.fromFile("/C:/Users/rrrrrr/Desktop/datastage/inputdata.txt")
val lines = inputData.getLines

val boundDate = LocalDate.parse("2018-01-01")

val matched = lines.filter(line =>
  Try(LocalDate.parse(line.substring(5, 15))) match {
    case Success(date) => date.isAfter(boundDate)
    case Failure(_) => false
  })

val outputData = new File("/C:/Users/rkumar0/Desktop/folder/output_N4.txt")

val writer= new BufferedWriter(new FileWriter(outputData))

matched.foreach(line => {
  writer.write(line)
  writer.newLine()
})
writer.flush()
writer.close()

对于基于您输入数据的示例输入（有一些错误的数据）：

094482017-06- 022 14012 000 0 30000A 002290{

094482017-326asd- 022 14012 000 0 30000A 002290{

094482017-06-10 022 14012 000 0 30000A 002290{

094482017-12-01 022 14012 000 0 30000A 002290{

094482018-07-10 022 14012 000 0 30000A 002290{

059412018-07-10 022 14013 000 0 30000A 002290{

015172018-07-10 046 17502 000 0 30000A 001699I

015172018-10-25 046 17502 000 0 30000A 001699I

输出将是：

094482018-07-10 022 14012 000 0 30000A 002290{

059412018-07-10 022 14013 000 0 30000A 002290{

015172018-07-10 046 17502 000 0 30000A 001699I

015172018-10-25 046 17502 000 0 30000A 001699I

更新解决方案 2（用于比较前 5 个字节）：

val matched = lines.filter(line =>
  Try(line.substring(0, 5).toInt) match {
    case Success(n) => n > 90000
    case Failure(_) => false
  }
)