RFR: 8354724: BufferedReader readAllLines and readString methods [v5]

[Shaojin Wen]

On Fri, 18 Apr 2025 02:26:10 GMT, Shaojin Wen <swen at openjdk.org> wrote:

>> Brian Burkhalter has updated the pull request incrementally with two additional commits since the last revision:
>> 
>>  - 8354724: Increment copyright year in Reader
>>  - 8354724: Move readString from BufferedReader to Reader
>
> src/java.base/share/classes/java/io/Reader.java line 424:
> 
>> 422:         int n;
>> 423:         while ((n = read(str)) != -1) {
>> 424:             result.append(str, 0, n);
> 
> If the characters in the Reader are always Latin1, this process will convert the UTF16 char[] to the LATIN1 encoded byte[] value in the StringBuilder every time, which will cause unnecessary performance overhead.

We need to provide a StringBuilder that creates a coder of UTF16 to avoid the unnecessary UTF16 to LATIN1 conversion overhead here. 

If we do not want to add a new public method, we can add an internal method and expose it through JLA for use here.

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PR Review Comment: https://git.openjdk.org/jdk/pull/24728#discussion_r2049921890