JSON 使用什么类型：string 还是 xstring？

Question

I create JSON with ABAP methods.

For example:

DATA(lo_json_writer) = cl_sxml_string_writer=>create( type = if_sxml=>co_xt_json ).
CALL TRANSFORMATION id
        SOURCE result = result
        RESULT XML lo_json_writer.

cl_abap_conv_in_ce=>create( )->convert(
        EXPORTING
          input = lo_json_writer->get_output( )
        IMPORTING
          data = json ).

Which data type should I use for json?

Use string or xstring ?

Answer 1

There's no "good way". Each solution has advantages and drawbacks.

If your data contains mostly "latin" characters, then use xstring with UTF-8 encoding, it will occupy less memory.

• xstring with UTF-8 encoding: one byte for common AZ/az/0-9 characters, two bytes for accentuated characters, and more bytes for characters from other languages (Chinese and so on).
• string : two bytes per character (encoding is like UCS-2 ), since all ABAP systems are now Unicode (ABAP >= 7.50).

Answer 2

According to this blog-entry( https://blogs.sap.com/2013/01/07/abap-and-json/ ): "For storing XML data in strings or internal tables, we recommend that you use byte strings or byte-like line types" Therefore i would use xstring.