use()
使用资源,并且无论是否有异常都会关闭资源,无需手动释放资源。
方法签名:
fun <T : Closeable?, R> T.use(block: (T) -> R): R
示例:
File("settings.gradle").inputStream().buffered().reader().use {
reader ->
println(reader.readText())
}
结果:
include ‘:app’
readLine()
从控制台读取一行
方法签名:
fun readLine(): String?
println()
在控制台打印,要换行
方法签名:
fun println(message: Any?)
fun println(message: Int)
fun println(message: Long)
fun println(message: Byte)
fun println(message: Short)
fun println(message: Char)
fun println(message: Boolean)
fun println(message: Float)
fun println(message: Double)
fun println(message: CharArray)
print()
在控制台打印,不换行
方法签名:
fun print(message: Any?)
fun print(message: Int)
fun print(message: Long)
fun print(message: Byte)
fun print(message: Short)
fun print(message: Char)
fun print(message: Boolean)
fun print(message: Float)
fun print(message: Double)
fun print(message: CharArray)
inputStream()
创建一个从ByteArray读取数据的InputStream
方法签名:
fun ByteArray.inputStream(): ByteArrayInputStream
fun ByteArray.inputStream(
offset: Int,
length: Int
): ByteArrayInputStream
示例:
val byteArrayInputStream = byteArrayOf(0, 1, 2, 3, 4, 5, 6, 7, 8, 9).inputStream()
val dstByteArray = ByteArray(5)
byteArrayInputStream.skip(5)
byteArrayInputStream.read(dstByteArray)
println(Arrays.toString(dstByteArray))
结果:
[5, 6, 7, 8, 9]