什么是 Scala 方式来实现这个 Java“byte[] to Hex"?班级 [英] What is/are the Scala way(s) to implement this Java "byte[] to Hex" class

问题描述

我对使用格式构建字符串的 Scala (2.8) 技术以及使这种功能在有用的地方(字节列表、字符串……?)轻松访问的有趣方法特别感兴趣.

I'm specifically interested in Scala (2.8) techniques for building strings with formats as well as interesting ways to make such a capability easily accessible where it's useful (lists of bytes, String, ...?)..

public class Hex {
  public static String valueOf (final byte buf[]) {
    if (null == buf) {
      return null;
    }
    final StringBuilder sb = new StringBuilder(buf.length * 2);
    for (final byte b : buf) {
      sb.append(String.format("%02X", b & 0xff));
    }
    return sb.toString();
  }

  public static String valueOf (final Byteable o) {
    return valueOf(o.toByteArray());
  }
}

这只是一个学习练习(所以 Java 的实用性和实现不是问题.)

This is only a learning exercise (so the utility and implementation of the Java isn't a concern.)

谢谢

推荐答案

这不会像处理代码那样处理 null.

This doesn't handle null in the same way as your code.

object Hex {

  def valueOf(buf: Array[Byte]): String = buf.map("%02X" format _).mkString

  def valueOf(o: Byteable): String = valueOf(o.toByteArray)

}

如果您希望能够处理可能为 null 的数组，则最好通过调用代码并执行以下操作来做到这一点:

If you want to be able to handle possibly-null arrays, you might be better doing that from calling code and doing:

val bytes: Array[Byte] = // something, possibly null
val string: Option[String] = Option(bytes).map(Hex.valueOf)

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