sop-java/sop-java/src/main/kotlin/sop/util/ProxyOutputStream.kt

76 lines
1.9 KiB
Kotlin

// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
//
// SPDX-License-Identifier: Apache-2.0
package sop.util
import java.io.ByteArrayOutputStream
import java.io.IOException
import java.io.OutputStream
/**
* [OutputStream] that buffers data being written into it, until its underlying output stream is
* being replaced. At that point, first all the buffered data is being written to the underlying
* stream, followed by any successive data that may get written to the [ProxyOutputStream]. This
* class is useful if we need to provide an [OutputStream] at one point in time when the final
* target output stream is not yet known.
*/
class ProxyOutputStream : OutputStream() {
private val buffer = ByteArrayOutputStream()
private var swapped: OutputStream? = null
@Synchronized
fun replaceOutputStream(underlying: OutputStream) {
this.swapped = underlying
swapped!!.write(buffer.toByteArray())
}
@Synchronized
@Throws(IOException::class)
override fun write(b: ByteArray) {
if (swapped == null) {
buffer.write(b)
} else {
swapped!!.write(b)
}
}
@Synchronized
@Throws(IOException::class)
override fun write(b: ByteArray, off: Int, len: Int) {
if (swapped == null) {
buffer.write(b, off, len)
} else {
swapped!!.write(b, off, len)
}
}
@Synchronized
@Throws(IOException::class)
override fun flush() {
buffer.flush()
if (swapped != null) {
swapped!!.flush()
}
}
@Synchronized
@Throws(IOException::class)
override fun close() {
buffer.close()
if (swapped != null) {
swapped!!.close()
}
}
@Synchronized
@Throws(IOException::class)
override fun write(i: Int) {
if (swapped == null) {
buffer.write(i)
} else {
swapped!!.write(i)
}
}
}