[2.x] refactor: Use InputStream.transferTo (#9212)

main/src/main/scala/sbt/internal/graph/rendering/TreeView.scala

@@ -17,7 +17,6 @@ import sjsonnew.support.scalajson.unsafe.{ CompactPrinter, Converter }
 
 import java.io.{ File, FileOutputStream, InputStream, OutputStream }
 import java.net.URI
-import scala.annotation.tailrec
 
 object TreeView {
   def createJson(graph: ModuleGraph): String = {
@@ -79,17 +78,6 @@ object TreeView {
     }
   }
 
-  def copy(from: InputStream, to: OutputStream): Unit = {
-    val buffer = new Array[Byte](65536)
-
-    @tailrec def rec(): Unit = {
-      val read = from.read(buffer)
-      if (read > 0) {
-        to.write(buffer, 0, read)
-        rec()
-      } else if (read == 0)
-        throw new IllegalStateException("InputStream.read returned 0")
-    }
-    rec()
-  }
+  def copy(from: InputStream, to: OutputStream): Unit =
+    from.transferTo(to)
 }

sbt-app/src/sbt-test/dependency-management/ivyless-publish-http/project/HttpPutServer.scala

@@ -21,9 +21,7 @@ object HttpPutServer {
           val in = ex.getRequestBody
           val out = new FileOutputStream(targetFile)
           try {
-            val buf = new Array[Byte](8192)
-            var n = 0
-            while ({ n = in.read(buf); n } != -1) out.write(buf, 0, n)
+            in.transferTo(out)
           } finally {
             out.close()
             in.close()

sbt-app/src/sbt-test/dependency-management/ivyless-publish-maven-http/project/HttpPutServer.scala

@@ -20,9 +20,7 @@ object HttpPutServer {
           val in = ex.getRequestBody
           val out = new FileOutputStream(targetFile)
           try {
-            val buf = new Array[Byte](8192)
-            var n = 0
-            while ({ n = in.read(buf); n } != -1) out.write(buf, 0, n)
+            in.transferTo(out)
           } finally {
             out.close()
             in.close()

sbt-app/src/sbt-test/lm-coursier/from/build.sbt

@@ -14,14 +14,7 @@ libraryDependencies += "com.chuusai" %% "shapeless" % "2.3.41" from {
     val is = url.openStream()
     val os = new java.io.FileOutputStream(f)
 
-    var read = -1
-    val b = new Array[Byte](16*1024)
-    while ({
-      read = is.read(b)
-      read >= 0
-    }) {
-      os.write(b, 0, read)
-    }
+    is.transferTo(os)
 
     is.close()
     os.close()