Hi,
The j.u.HexFormat class has methods that append hex formatted byte
arrays to an Appendable such as StringBuilder.
The `toHexDigits` methods return strings with the hex values of byte,
short, char, int, and long.
Similar `formatHex` methods could be added with an Appendable argument
would keep the focus in HexFormat for the formatting but allows the
result to be placed directly in a StringBuilder.
For example in this draft PR. https://github.com/openjdk/jdk/pull/16105
Regards, Roger
On 10/2/23 10:01 AM, 温绍锦(高铁) wrote:
StringTemplate is great and I wish I can submit PR to improve it. But
I still think StringBuilder.appendHex is a basic API, not a formatted
API. Just like Integer.toHexString and Long.toHexString, they are very
commonly used and should be built-in.
------------------------------------------------------------------
发件人：温绍锦(高铁) <shaojin.we...@alibaba-inc.com>
发送时间：2023年10月2日(星期一) 20:46
收件人：Mark Reinhold <mark.reinh...@oracle.com>; Claes Redestad
<claes.redes...@oracle.com>
抄 送：core-libs-dev@openjdk.org <core-libs-dev@openjdk.org>
主 题：回复：Adding appendHex method to StringBuilder
Using String Template FMT has better performance and better code
readability. But String Template does not yet support
for/while/if/switch. Is there any plan to enhance String Template
to support for/while/if/switch? The following scenarios cannot be
implemented using String.format or String Template. I think
whether to build in support for foo(bar(x)) depends on whether it
is a common enough method.
```java
package java.net;
class Inet6Address extends InetAddress {
static String numericToTextFormat(byte[] src) {
StringBuilder sb = new StringBuilder(39);
for (int i = 0; i < (INADDRSZ / INT16SZ); i++) {
sb.append(Integer.toHexString(((src[i<<1]<<8) & 0xff00)
| (src[(i<<1)+1] & 0xff)));
if (i < (INADDRSZ / INT16SZ) -1 ) {
sb.append(":");
}
}
return sb.toString();
}
}
class SocketPermission {
private boolean authorizedIPv6(String cname, byte[] addr) {
String authHost = "";
InetAddress auth;
try {
StringBuilder sb = new StringBuilder(39);
for (int i = 15; i >= 0; i--) {
sb.append(Integer.toHexString(((addr[i]) & 0x0f)));
sb.append('.');
sb.append(Integer.toHexString(((addr[i] >> 4) & 0x0f)));
sb.append('.');
}
...
}
}
```
```java
package sun.security.krb5.internal.crypto.dk;
class DkCrypto {
static String bytesToString(byte[] digest) {
// Get character representation of digest
StringBuilder digestString = new StringBuilder();
for (int i = 0; i < digest.length; i++) {
if ((digest[i] & 0x000000ff) < 0x10) {
digestString.append('0').append(Integer.toHexString(digest[i] &
0x000000ff));
} else {
digestString.append(
Integer.toHexString(digest[i] & 0x000000ff));
}
}
return digestString.toString();
}
}
```
- wenshao
------------------------------------------------------------------
发件人：Mark Reinhold <mark.reinh...@oracle.com>
发送时间：2023年10月2日(星期一) 20:19
收件人：Claes Redestad <claes.redes...@oracle.com>
抄 送：温绍锦(高铁) <shaojin.we...@alibaba-inc.com>;
core-libs-dev@openjdk.org <core-libs-dev@openjdk.org>
主 题：Re: Adding appendHex method to StringBuilder
2023/10/2 7:22:55 -0400, claes.redes...@oracle.com:
> I think this goes against the grain: StringBuilder is a simple
builder
> for non-localized unformatted output. For formatted output there’s
> Formatter, String.format and, with JEP 430[1], FMT."..." to help
output
> string data in more advanced, formatted and localized ways.
Agreed.
If we were to introduce a `fooBar(x)` method for every common
`foo(bar(x))` expression in the JDK code base then our APIs
would fast become inscrutable.
- Mark
