Simple database: Difference between revisions
Added Kotlin
(Added Kotlin) |
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Line 2,104:
item5,2014-06-03 19:30:23,cat3</pre>
=={{header|Kotlin}}==
{{trans|Java}}
... though not quite the same.
<lang scala>// version 1.2.31
import java.text.SimpleDateFormat
import java.util.Date
import java.io.File
import java.io.IOException
val file = File("simdb.csv")
class Item(
val name: String,
val date: String,
val category: String
) : Comparable<Item> {
override fun compareTo(other: Item) = date.compareTo(other.date)
override fun toString() = "$name, $date, $category"
}
fun addItem(input: Array<String>) {
if (input.size < 2) {
printUsage()
return
}
val sdf = SimpleDateFormat("yyyy-MM-dd HH:mm:ss")
val date = sdf.format(Date())
val cat = if (input.size == 3) input[2] else "none"
store(Item(input[1], date, cat))
}
fun printLatest(a: Array<String>) {
val db = load()
if (db.isEmpty()) {
println("No entries in database.")
return
}
// no need to sort db as items are added chronologically
if (a.size == 2) {
var found = false
for (item in db.reversed()) {
if (item.category == a[1]) {
println(item)
found = true
break
}
}
if (!found) println("There are no items for category '${a[1]}'")
}
else println(db[db.lastIndex])
}
fun printAll() {
val db = load()
if (db.isEmpty()) {
println("No entries in database.")
return
}
// no need to sort db as items are added chronologically
for (item in db) println(item)
}
fun load(): MutableList<Item> {
val db = mutableListOf<Item>()
try {
file.forEachLine { line ->
val item = line.split(", ")
db.add(Item(item[0], item[1], item[2]))
}
}
catch (e: IOException) {
println(e)
System.exit(1)
}
return db
}
fun store(item: Item) {
try {
file.appendText("$item\n")
}
catch (e: IOException) {
println(e)
}
}
fun printUsage() {
println("""
|Usage:
| simdb cmd [categoryName]
| add add item, followed by optional category
| latest print last added item(s), followed by optional category
| all print all
| For instance: add "some item name" "some category name"
""".trimMargin())
}
fun main(args: Array<String>) {
if (args.size !in 1..3) {
printUsage()
return
}
file.createNewFile() // create file if it doesn't already exist
when (args[0].toLowerCase()) {
"add" -> addItem(args)
"latest" -> printLatest(args)
"all" -> printAll()
else -> printUsage()
}
}</lang>
{{out}}
Sample session.
<pre>
$ java -jar SimpleDatabase.jar add item1
$ java -jar SimpleDatabase.jar add item2
$ java -jar SimpleDatabase.jar add item3 cat3
$ java -jar SimpleDatabase.jar add item4 cat3
$ java -jar SimpleDatabase.jar add item5 cat3
$ java -jar SimpleDatabase.jar latest
item5, 2018-03-23 16:49:46, cat3
$ java -jar SimpleDatabase.jar latest none
item2, 2018-03-23 16:49:28, none
$ java -jar SimpleDatabase.jar latest cat4
There are no items for category 'cat4'
$ java -jar SimpleDatabase.jar all
item1, 2018-03-23 16:49:25, none
item2, 2018-03-23 16:49:28, none
item3, 2018-03-23 16:49:34, cat3
item4, 2018-03-23 16:49:40, cat3
item5, 2018-03-23 16:49:46, cat3
</pre>
=={{header|Perl}}==
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