1. Read data for each line in the file
def main(args: Array[String]): Unit = {
// pay attention to the encoding format of the file. If the encoding format is not correct, read the wrong report.
val file: BufferedSource = Source.fromFile("F:\files\file.txt","GBK");
val lines: Iterator[String] = file.getLines()
for(line <- lines){
println(line)
}
// Pay attention to closing files
file.close()
}If you want to convert the file content to an array, call toArray directly.
2. Reading Lexical Units and Numbers
If you want to read characters in groups separated by a character or a regular expression, you can do this:
def main(args: Array[String]): Unit = {
val file: BufferedSource = Source.fromFile("F:\files\file2.txt","GBK");
val split: Array[String] = file.mkString.split(" ")
println(split.mkString("\t"))
file.close()
}
3. Reading Network Resources, File Writing, Console Operation
1, read network resources
def main(args: Array[String]): Unit = {
val source: BufferedSource = Source.fromURL("http://www.baidu.com")
val string: String = source.mkString
println(string)
source.close()
}
2. File Writing Operation
def main(args: Array[String]): Unit = {
val writer = new PrintWriter("F:files\printWriter.txt")
for(i <- 1 to 100){
writer.println(i)
writer.flush()
}
writer.close()
}
3. Console Interaction
def main(args: Array[String]): Unit = {
// Console Interaction -- Old API
Print ("Please enter content:")
val consoleLine1 = Console.readLine()
Println ("What I just entered is:" + consoleLine1)
// Console Interaction -- New API
Print ("Please enter content (new API):")
val consoleLine2 = StdIn.readLine()
Println ("What I just entered is:" + consoleLine2)
}4. Serialization in Scala
@SerialVersionUID(1L)
class Person extends Serializable{
override def toString = name + "," + age
val name = "Nick"
val age = 20
}
object PersonMain extends App{
override def main(args: Array[String]): Unit = {
import java.io.{FileOutputStream, FileInputStream, ObjectOutputStream, ObjectInputStream}
val nick = new Person
val out = new ObjectOutputStream(new FileOutputStream("Nick.obj"))
out.writeObject(nick)
out.close()
val in = new ObjectInputStream(new FileInputStream("Nick.obj"))
val saveNick = in.readObject()
in.close()
println(saveNick)
}
}5. Regular expressions in Scala
We can match all matches in a sentence through regular expressions and output:
def main(args: Array[String]): Unit = {
import scala.util.matching.Regex
val pattern1 = new Regex("(S|s)cala")
val pattern2 = "(S|s)cala".r
val str = "Scala is scalable and cool"
println((pattern2 findAllIn str).mkString(","))
}
The above is the whole content of this article. I hope it will be helpful to everyone’s study, and I hope you will support developpaer more.