Scala學習筆記(8)—— Scala操作外部資料
阿新 • • 發佈:2018-12-30
1 Scala 讀取檔案
package com.scalatest.scala.class09
import java.net.URL
import scala.io.Source
object FileApp {
def main(args: Array[String]): Unit = {
val file = Source.fromFile("d:/test.txt")
def readLine() = {
for (line <- file.getLines()) {
println( line)
}
}
//readLine()
def readChar() = {
for (ele <- file) {
println(ele)
}
}
// readChar()
def readNet() = {
val file = Source.fromURL("http://www.baidu.com")
for (line <- file.getLines()) {
println(line)
}
}
readNet()
}
}
2 Scala 操作 MySQL 資料庫
- POM 新增依賴
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version >5.1.38</version>
</dependency>
package com.scalatest.scala.class09
import java.sql.{Connection, DriverManager, Statement}
object MySQLApp {
def main(args: Array[String]): Unit = {
val url = "jdbc:mysql://localhost:3306/mysql"
val username = "root"
val password = "root"
var connection: Connection = null
var statement: Statement = null
try {
classOf[com.mysql.jdbc.Driver]
connection = DriverManager.getConnection(url, username, password)
statement = connection.createStatement()
val resultSet = statement.executeQuery("select host,user from user")
while (resultSet.next()) {
val host = resultSet.getString("host")
val user = resultSet.getString("user")
println(s"$host,$user")
}
} catch {
case e: Exception => e.printStackTrace()
} finally {
if (connection == null) {
connection.close()
}
}
}
}
3 Scala 讀取 XML 檔案
<symbols>
<symbol ticker="AAPL">
<units>200</units>
</symbol>
<units>300</units>
<symbol ticker="AAPL">
<units>400</units>
</symbol>
</symbols>
3.1 讀取 XML 內容
package com.scalatest.scala.class09
import java.io.{FileInputStream, InputStreamReader}
import scala.xml.XML
object XMLApp {
def main(args: Array[String]): Unit = {
loadXML()
}
def loadXML(): Unit = {
// val xml = XML.load(this.getClass.getClassLoader.getResource("test.xml"))
// println(xml)
// val xml = XML.load(new FileInputStream("D:\\Data\\JavaProject\\scalatest\\src\\main\\resources\\test.xml"))
// println(xml)
val xml = XML.load(new InputStreamReader(
new FileInputStream("D:\\Data\\JavaProject\\scalatest\\src\\main\\resources\\test.xml")
))
println(xml)
}
}