Require Java 8 from now on

cli/src/main/scala-2.12/coursier/cli/Bootstrap.scala

@@ -2,6 +2,7 @@ package coursier
 package cli
 
 import java.io.{ByteArrayInputStream, ByteArrayOutputStream, File, FileInputStream, IOException}
+import java.nio.charset.StandardCharsets.UTF_8
 import java.nio.file.Files
 import java.nio.file.attribute.PosixFilePermission
 import java.util.Properties
@@ -156,7 +157,7 @@ object Bootstrap extends CaseApp[BootstrapOptions] {
         entry.setTime(time)
 
         outputZip.putNextEntry(entry)
-        outputZip.write(content.getBytes("UTF-8"))
+        outputZip.write(content.getBytes(UTF_8))
         outputZip.closeEntry()
       }
 
@@ -207,7 +208,7 @@ object Bootstrap extends CaseApp[BootstrapOptions] {
         "exec java -jar " + options.options.javaOpt.map(s => "'" + s.replace("'", "\\'") + "'").mkString(" ") + " \"$0\" \"$@\""
       ).mkString("", "\n", "\n")
 
-      try FileUtil.write(output0, shellPreamble.getBytes("UTF-8") ++ buffer.toByteArray)
+      try FileUtil.write(output0, shellPreamble.getBytes(UTF_8) ++ buffer.toByteArray)
       catch { case e: IOException =>
         Console.err.println(s"Error while writing $output0${Option(e.getMessage).fold("")(" (" + _ + ")")}")
         sys.exit(1)

cli/src/main/scala-2.12/coursier/cli/SparkOutputHelper.scala

@@ -1,6 +1,7 @@
 package coursier.cli
 
 import java.io.{BufferedReader, File, InputStream, InputStreamReader, PipedInputStream, PipedOutputStream, PrintStream}
+import java.nio.charset.StandardCharsets.UTF_8
 
 import coursier.internal.FileUtil
 
@@ -55,7 +56,7 @@ object SparkOutputHelper {
                 if (!written) {
                   println(s"Detected YARN app ID $id")
                   Option(yarnAppFile.getParentFile).foreach(_.mkdirs())
-                  FileUtil.write(yarnAppFile, id.getBytes("UTF-8"))
+                  FileUtil.write(yarnAppFile, id.getBytes(UTF_8))
                   written = true
                 }
               }

cli/src/main/scala-2.12/coursier/cli/spark/Assembly.scala

@@ -2,6 +2,8 @@ package coursier.cli.spark
 
 import java.io.{File, FileInputStream, FileOutputStream}
 import java.math.BigInteger
+import java.nio.charset.StandardCharsets.UTF_8
+import java.nio.file.{Files, StandardCopyOption}
 import java.security.MessageDigest
 import java.util.jar.{Attributes, JarFile, JarOutputStream, Manifest}
 import java.util.regex.Pattern
@@ -207,7 +209,7 @@ object Assembly {
     extraDependencies: Seq[String],
     options: CommonOptions,
     artifactTypes: Set[String],
-    checksumSeed: Array[Byte] = "v1".getBytes("UTF-8")
+    checksumSeed: Array[Byte] = "v1".getBytes(UTF_8)
   ): Either[String, (File, Seq[File])] = {
 
     val helper = sparkJarsHelper(scalaVersion, sparkVersion, yarnVersion, default, extraDependencies, options)
@@ -240,7 +242,7 @@ object Assembly {
     md.update(checksumSeed)
 
     for (c <- checksums.sorted) {
-      val b = c.getBytes("UTF-8")
+      val b = c.getBytes(UTF_8)
       md.update(b, 0, b.length)
     }
 
@@ -271,7 +273,7 @@ object Assembly {
         val tmpDest = new File(dest.getParentFile, s".${dest.getName}.part")
         // FIXME Acquire lock on tmpDest
         Assembly.make(jars, tmpDest, assemblyRules)
-        FileUtil.atomicMove(tmpDest, dest)
+        Files.move(tmpDest.toPath, dest.toPath, StandardCopyOption.ATOMIC_MOVE)
         Right((dest, jars))
       }.left.map(_.describe)
   }

cli/src/test/scala-2.12/coursier/cli/CliBootstrapIntegrationTest.scala

@@ -1,6 +1,7 @@
 package coursier.cli
 
 import java.io._
+import java.nio.charset.StandardCharsets.UTF_8
 import java.util.zip.ZipInputStream
 
 import caseapp.core.RemainingArgs
@@ -69,7 +70,7 @@ class CliBootstrapIntegrationTest extends FlatSpec with CliTestLib {
 
       val zis = new ZipInputStream(new ByteArrayInputStream(actualContent))
 
-      val lines = new String(zipEntryContent(zis, "bootstrap-isolation-foo-jar-urls"), "UTF-8").lines.toVector
+      val lines = new String(zipEntryContent(zis, "bootstrap-isolation-foo-jar-urls"), UTF_8).lines.toVector
 
       val extensions = lines
         .map { l =>