StreamsStrings example

jeorg-kotlin-coroutines/coroutines-crums-group-1/src/main/kotlin/org/jesperancinha/ktd/StreamsStrings.kt

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+package org.jesperancinha.ktd
+
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.async
+import kotlinx.coroutines.withContext
+import java.io.InputStream
+
+class StreamsStrings {
+    suspend fun executeCommand(commandArgs: List<String>): ProcessResult = withContext(
+        Dispatchers.IO
+    ) {
+        runCatching {
+            val process = ProcessBuilder(commandArgs).start()
+            val outputStream = async {
+                println("Context for output stream -> $coroutineContext -> Thread -> ${Thread.currentThread()}")
+                readStream(process.inputStream) }
+            val errorStream = async {
+                println("Context for error stream -> $coroutineContext -> Thread -> ${Thread.currentThread()}")
+                readStream(process.errorStream)
+            }
+            println("Context for exit code -> $coroutineContext -> Thread -> ${Thread.currentThread()}")
+            val exitCode =  process.waitFor()
+            ProcessResult(
+                exitCode = exitCode,
+                message = outputStream.await(),
+                errorMessage = errorStream.await()
+            )
+        }.onFailure{
+            ProcessResult(
+                exitCode = -1,
+                message = "",
+                errorMessage = it.localizedMessage
+            )
+        }.getOrThrow()
+    }
+
+    private fun readStream(inputStream: InputStream) =
+        inputStream.bufferedReader().use { reader -> reader.readText() }
+
+    data class ProcessResult(val exitCode: Int, val message: String, val errorMessage: String)
+}

jeorg-kotlin-coroutines/coroutines-crums-group-1/src/test/kotlin/org/jesperancinha/ktd/StreamsStringsTest.kt

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+package org.jesperancinha.ktd
+
+import io.kotest.common.runBlocking
+import io.kotest.matchers.string.shouldContain
+import kotlin.test.Test
+
+class StreamsStringsTest {
+
+    private val streamsStrings by lazy { StreamsStrings() }
+
+    @Test
+    fun `should run command correctly`(): Unit = runBlocking {
+
+        val executeCommand = streamsStrings.executeCommand(listOf("java", "-version"))
+        println(executeCommand)
+        executeCommand.errorMessage shouldContain "JDK"
+
+    }
+}