scala文件读写

import java.io.{File, FileWriter, PrintWriter}

import scala.collection.mutable
import scala.collection.mutable.ListBuffer
import scala.io.Source

object io_test {
  def main(args: Array[String]): Unit = {

    // 获得当前的绝对路径和相对路径
    val file = new File(".")
    println(file.getAbsolutePath)
    println(file.getPath)

    test_8()
    test_10()
  }

  // 绝对路径读取， 一行一行读
  def test_1(): Unit = {
    val source = Source.fromFile("C:\\Users\\14165\\Desktop\\test\\src\\main\\data\\2017-04-16.txt")
    val lines = source.getLines()
    println(lines.getClass) // class scala.io.BufferedSource$BufferedLineIterator

    for (line <- lines) {
      println(line)
      println(line.getClass) // class java.lang.String
    }
    source.close()
  }

  // 绝对路径读取， 转化为行列表
  def test_2(): Unit = {
    val source2 = Source.fromFile("C:\\Users\\14165\\Desktop\\test\\src\\main\\data\\2017-04-16.txt")
    val lines = source2.getLines()
    val linesList = lines.toList
    println(linesList.size)
    println(linesList(0))
    println(linesList(0).split(" "))
    source2.close()

  }

  // 直接读成字符串
  def test_3(): Unit = {
    val source3 = Source.fromFile("C:\\Users\\14165\\Desktop\\test\\src\\main\\data\\2017-04-16.txt")
    val lines3 = source3.mkString
    println(lines3)
    source3.close()
  }

  // 相对路径
  def test_4(): Unit = {
    val f = Source.fromFile("src\\main\\resources\\2017-04-16.txt")
    var count = 0
    for (line <- f.getLines()){
      count += 1
    }
    println(count)
  }

  // 相对路径读取
  def test_5(): Unit = {
    val f = new File(getClass.getClassLoader.getResource("2017-04-16.txt").getPath)
    val source = Source.fromFile(f, "UTF-8")
    val lines = source.getLines()
    for (line <- lines) {
      println(line)
    }
    source.close()
  }

  // 读取加工存储为List
  def test_6(): List[String] = {
    val f = new File(getClass.getClassLoader.getResource("2017-04-16.txt").getPath)
    val source = Source.fromFile(f, "UTF-8")
    val tmpList = ListBuffer[String]()
    for (line <- source.getLines()) {
      tmpList += line
    }
    tmpList.toList
  }

  // 读取加工存储为字典
  def test_7(): mutable.HashMap[String, Double] = {
    val f = new File(getClass.getClassLoader.getResource("2017-04-16.txt").getPath)
    val source = Source.fromFile(f, "UTF-8")
    val tmpMap = mutable.HashMap[String, Double]()
    for (line <- source.getLines()) {
      val lineItems = line.split("\t")
      val name = lineItems(0)
      val price = lineItems(1).split("￥")(1).replace(",", "").toDouble
      tmpMap(name) = price
    }
    tmpMap
  }

  // 写入文件
  def test_8(): Unit = {
    val out = new PrintWriter(new File("D:\\write_res1.txt"))
    for (i <- 1 to 100) {
      out.println(i)
    }
    out.close()

  }

  def test_9(): Unit = {
//    val out = new FileWriter(new File(getClass.getClassLoader.getResource("write_res2.txt").getPath))
    val out = new FileWriter(new File("D:\\write_res2.txt"))
    for (i <- 1 to 10) {
      out.write(i.toString + "\r\n")
    }
    out.close()
  }

  def test_10(): Unit = {
    val source = Source.fromFile(new File(getClass.getClassLoader.getResource("2017-04-16.txt").getPath))
    val tmpMap = new mutable.HashMap[String, Double]()
    for (line <- source.getLines()){
      val tmpItem = line.split("\t")
      val name = tmpItem(0).toString
      val price = tmpItem(1).split("￥")(1).replace(",", "").toDouble
      tmpMap(name) = price
    }
    source.close()

    val out = new FileWriter(new File("D:\\write_res3.txt"))
    for ((name, price) <- tmpMap) {
      out.write(name + "," + price.toString + "\r\n")
    }
    out.close()

  }

def test_11(): Unit = {
    val out = new FileWriter(new File("D:\\write_res2.txt"))
    val source = Source.fromFile(new File(getClass.getClassLoader.getResource("2017-04-16.txt").getPath))
    for (line <- source.getLines()) {
      val name = line.split("\t")(0).toString
      val price = line.split("\t")(1).split("￥")(1).replace(",", "").toDouble
      out.write(name + "," + price + "\r\n")
    }
    source.close()
    out.close()
  }

}