Java Unicode CodePoint Reader

CodePointReader.java

public final class CodePointReader implements AutoCloseable
{
  private final Reader reader;

  public CodePointReader(Reader reader)
  {
    this.reader = reader;
  }

  public int read()
  {
    try
    {
      int highInt = reader.read();
      if (highInt == -1)
        return -1;
      char highChar = (char) highInt;
      if (!Character.isHighSurrogate(highChar))
        return highInt;
      int lowInt = reader.read();
      char lowChar = (char) lowInt;
      if ((lowInt == -1) || !Character.isLowSurrogate(lowChar))
        throw new RuntimeException("No corresponding low surrogate found [found '" + lowChar + "] for high surrogate [" + highChar + "]");
      return Character.toCodePoint(highChar, lowChar);
    }
    catch (IOException e)
    {
      throw new RuntimeException(e);
    }
  }

  @Override
  public void close() throws Exception
  {
    reader.close();
  }
}