batch compiler.util: writeToDisk use Files.write()

instead of streaming, because less source and it is a bit faster.
For example MethodVerifyTest on windows: 65s->64s

org.eclipse.jdt.core.compiler.batch/src/org/eclipse/jdt/internal/compiler/util/Util.java

@@ -14,9 +14,7 @@
  *******************************************************************************/
 package org.eclipse.jdt.internal.compiler.util;
 
-import java.io.BufferedOutputStream;
 import java.io.File;
-import java.io.FileOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.PrintWriter;
@@ -231,7 +229,6 @@ public interface Displayable {
 		String displayString(Object o);
 	}
 
-	private static final int DEFAULT_WRITING_SIZE = 1024;
 	public final static String UTF_8 = "UTF-8";	//$NON-NLS-1$
 	public static final String LINE_SEPARATOR = System.getProperty("line.separator"); //$NON-NLS-1$
 
@@ -397,9 +394,9 @@ public static byte[] getFileByteContent(File file) throws IOException {
 	public static char[] getFileCharContent(File file, String encoding) throws IOException {
 		return org.eclipse.jdt.internal.compiler.util.Util.getBytesAsCharArray(Files.readAllBytes(file.toPath()), encoding);
 	}
-	private static FileOutputStream getFileOutputStream(boolean generatePackagesStructure, String outputPath, String relativeFileName) throws IOException {
+	private static File getFile(boolean generatePackagesStructure, String outputPath, String relativeFileName) throws IOException {
 		if (generatePackagesStructure) {
-			return new FileOutputStream(new File(buildAllDirectoriesInto(outputPath, relativeFileName)));
+			return new File(buildAllDirectoriesInto(outputPath, relativeFileName));
 		} else {
 			String fileName = null;
 			char fileSeparatorChar = File.separatorChar;
@@ -422,7 +419,7 @@ private static FileOutputStream getFileOutputStream(boolean generatePackagesStru
 					fileName = outputPath + fileSeparator + relativeFileName.substring(indexOfPackageSeparator + 1, length);
 				}
 			}
-			return new FileOutputStream(new File(fileName));
+			return new File(fileName);
 		}
 	}
 
@@ -915,34 +912,14 @@ public static String toString(Object[] objects, Displayable renderer) {
 	 * @param relativeFileName the given relative file name
 	 * @param classFile the given classFile to write
 	 */
-	public static void writeToDisk(boolean generatePackagesStructure, String outputPath, String relativeFileName, ClassFile classFile) throws IOException {
-		FileOutputStream file = getFileOutputStream(generatePackagesStructure, outputPath, relativeFileName);
-		/* use java.nio to write
-		if (true) {
-			FileChannel ch = file.getChannel();
-			try {
-				ByteBuffer buffer = ByteBuffer.allocate(classFile.headerOffset + classFile.contentsOffset);
-				buffer.put(classFile.header, 0, classFile.headerOffset);
-				buffer.put(classFile.contents, 0, classFile.contentsOffset);
-				buffer.flip();
-				while (true) {
-					if (ch.write(buffer) == 0) break;
-				}
-			} finally {
-				ch.close();
-			}
-			return;
-		}
-		*/
-		try (BufferedOutputStream output = new BufferedOutputStream(file, DEFAULT_WRITING_SIZE)) {
-			// if no IOException occured, output cannot be null
-			output.write(classFile.header, 0, classFile.headerOffset);
-			output.write(classFile.contents, 0, classFile.contentsOffset);
-			output.flush();
-		} catch(IOException e) {
-			throw e;
-		}
+	public static void writeToDisk(boolean generatePackagesStructure, String outputPath, String relativeFileName,
+			ClassFile classFile) throws IOException {
+		File file = getFile(generatePackagesStructure, outputPath, relativeFileName);
+		byte[] bytes = Arrays.copyOf(classFile.header, classFile.headerOffset + classFile.contentsOffset);
+		System.arraycopy(classFile.contents, 0, bytes, classFile.headerOffset, classFile.contentsOffset);
+		Files.write(file.toPath(), bytes);
 	}
+
 	@SuppressWarnings({ "rawtypes", "unchecked" })
 	public static void recordNestedType(ClassFile classFile, TypeBinding typeBinding) {
 		if (classFile.visitedTypes == null) {