Example 2

This ABAP report is included in the addon package.

&---------------------------------------------------------------------
& Report /CEX/JMP_JSON_EXAMPLE2
&---------------------------------------------------------------------
& This is example code to show the usage of JSON within ABAP
& Store ABAP types into JSON objects for transferring to external
& applications. Map inbound JSON data back to (complex) ABAP objects
&---------------------------------------------------------------------
& (c) 2014 joomp.de
& last changed 2014/02/05
&---------------------------------------------------------------------
REPORT /cex/jmp_json_example2 NO STANDARD PAGE HEADING LINE-SIZE 1023.

• -------- interface
  PARAMETERS: p_max TYPE sqf_max_rows DEFAULT 10.

• -------- local data
  DATA: lr_json TYPE REF TO /cex/cl_jmp_json.
  DATA: lr_mapper TYPE REF TO /cex/cl_jmp_json_mapper.
  DATA: lr_output TYPE REF TO /cex/cl_jmp_json_object.
  DATA: lr_jdata TYPE REF TO /cex/if_jmp_json.
  DATA: lr_parsed TYPE REF TO /cex/if_jmp_json.
  DATA: lr_input TYPE REF TO /cex/cl_jmp_json_object.

DATA: lv_output TYPE string.
DATA: lv_message TYPE string.
DATA: lv_lin TYPE i.

DATA: lr_sflight_t TYPE REF TO /cex/cl_jmp_json_array.
DATA: lr_sflight_s TYPE REF TO /cex/cl_jmp_json_object.
DATA: lv_sflight_s TYPE string.
DATA: lt_sflight TYPE TABLE OF sflight.
DATA: ls_sflight LIKE LINE OF lt_sflight.
DATA: ls_usr02 TYPE usr02.

DATA: BEGIN OF ls_complex,
table_sflight TYPE TABLE OF sflight,
struc_sflight TYPE sflight,
string_sflight TYPE string,
date_sflight TYPE sydatum,
integer_sflight TYPE i,
double_sflight TYPE /cex/jmp_json_double,
usr02 TYPE usr02,
END OF ls_complex.

FIELD-SYMBOLS: <field> TYPE data.

• -------- local macro
  DEFINE write_struc.
  do.
• bind field number #
  unassign <field>.
  assign component sy-index of structure &1 to <field>.
• output
  if <field> is assigned.
  write: / sy-index, <field>.
  else.
  exit. " from loop
  endif.

• want to leave ?
  if &2 > 0 and sy-index > &2.
  exit.
  endif.
  enddo.
  END-OF-DEFINITION.

• --------- ACTION
  START-OF-SELECTION.

• -------- 0) select some data

• sflight
  SELECT * FROM sflight
  INTO TABLE lt_sflight
  UP TO p_max ROWS.
  DESCRIBE TABLE lt_sflight LINES lv_lin.
  IF lv_lin EQ 0.
  WRITE: / 'No data selected in table SFLIGHT'.
  EXIT.
  ELSE.
  WRITE: / 'Zeilen gelesen:', lv_lin.
  ULINE.
  ENDIF.
  READ TABLE lt_sflight INTO ls_sflight INDEX 1.

• usr02
  SELECT SINGLE * FROM usr02
  INTO ls_usr02
  WHERE bname = sy-uname.
  write_struc ls_usr02 15.

• -------- 1) get the main json handler
  lr_json = /cex/cl_jmp_json=>get_instance( ).

• -------- 2) get the mapper and an empty output object
  lr_mapper = lr_json->get_mapper( ).
  lr_output = lr_json->new_object( ).

• -------- 3) add different data types to json object

• table example
  CLEAR lr_jdata.
  lr_jdata = lr_mapper->map_to_json( lt_sflight ).
  IF lr_jdata IS NOT INITIAL.
  lr_output->put( iv_id = 'table_sflight' ir_data = lr_jdata ).
  ENDIF.
• structure example
  CLEAR lr_jdata.
  lr_jdata = lr_mapper->map_to_json( ls_sflight ).
  IF lr_jdata IS NOT INITIAL.
  lr_output->put( iv_id = 'struc_sflight' ir_data = lr_jdata ).
  ENDIF.
• string example
  CLEAR lr_jdata.
  lr_jdata = lr_mapper->map_to_json( ls_sflight-carrid ).
  IF lr_jdata IS NOT INITIAL.
  lr_output->put( iv_id = 'string_sflight' ir_data = lr_jdata ).
  ENDIF.
• date example
  CLEAR lr_jdata.
  lr_jdata = lr_mapper->map_to_json( ls_sflight-fldate ).
  IF lr_jdata IS NOT INITIAL.
  lr_output->put( iv_id = 'date_sflight' ir_data = lr_jdata ).
  ENDIF.
• integer example
  CLEAR lr_jdata.
  lr_jdata = lr_mapper->map_to_json( ls_sflight-seatsmax ).
  IF lr_jdata IS NOT INITIAL.
  lr_output->put( iv_id = 'integer_sflight' ir_data = lr_jdata ).
  ENDIF.
• double example
  CLEAR lr_jdata.
  lr_jdata = lr_mapper->map_to_json( ls_sflight-paymentsum ).
  IF lr_jdata IS NOT INITIAL.
  lr_output->put( iv_id = 'double_sflight' ir_data = lr_jdata ).
  ENDIF.

• struc with other data types example
  CLEAR lr_jdata.
  lr_jdata = lr_mapper->map_to_json( ls_usr02 ).
  IF lr_jdata IS NOT INITIAL.
  lr_output->put( iv_id = 'usr02' ir_data = lr_jdata ).
  ENDIF.

• -------- 4) get the json as string for output, reset vars
  lv_output = lr_output->/cex/if_jmp_json~to_string( ).
  WRITE: / 'JSON String:'.
  WRITE: / lv_output.

REFRESH lt_sflight.
CLEAR ls_sflight.

• ========================= PARSE STRING TO JSON
  ULINE.

• -------- 5) get json data from output string
  lr_parsed = lr_json->parse( lv_output ).
  IF lr_parsed IS INITIAL.
  WRITE: / 'Error parsing json input'.
  EXIT.
  ENDIF.

• -------- 6) map json to complex abap object
  CLEAR ls_complex.
  CALL METHOD lr_mapper->map_from_json
  EXPORTING
  ir_json = lr_parsed
  CHANGING
  cv_data = ls_complex
  cv_message = lv_message
  EXCEPTIONS
  failed = 1
  OTHERS = 2.
  IF sy-subrc <> 0.
  WRITE: / 'Errors occured while mapping json to abap:', lv_message.
  ELSE.

• write the usr02 entry
  write_struc ls_complex-usr02 15.
  ULINE.

• lt_sflight
  DESCRIBE TABLE ls_complex-table_sflight LINES lv_lin.
  WRITE: / 'Lines of SFLIGHT parsed from json string (complex):', lv_lin.
  ENDIF.

• -------- 7) map json data to abap manually

• the main json is an object
  lr_input ?= lr_parsed.

• get the subobjects via known id
  lr_sflight_t = lr_input->get_array( 'table_sflight' ).
  lr_sflight_s = lr_input->get_object( 'struc_sflight' ).
  lv_sflight_s = lr_input->get_string( 'string_sflight' ).

• read data back to lt_sflight
  IF lr_sflight_t IS INITIAL.
  WRITE: / 'table sflight not in json input'.
  ELSE.
  REFRESH lt_sflight.
  CALL METHOD lr_mapper->map_from_json
  EXPORTING

• is_ddic =
  ir_json = lr_sflight_t
  CHANGING
  cv_data = lt_sflight
  cv_message = lv_message
  EXCEPTIONS
  failed = 1
  OTHERS = 2.
  IF sy-subrc <> 0.
  WRITE: / 'Errors occured while mapping json to abap'.
  ELSE.
  DESCRIBE TABLE lt_sflight LINES lv_lin.
  WRITE: / 'Lines of SFLIGHT parsed from json string (manual) :', lv_lin.
  ENDIF.
  ENDIF.

• read data back to ls_sflight
  IF lr_sflight_s IS INITIAL.
  WRITE: / 'structure sflight is not in json input'.
  ELSE.
  CLEAR ls_sflight.
  CALL METHOD lr_mapper->map_from_json
  EXPORTING
  ir_json = lr_sflight_s
  CHANGING
  cv_data = ls_sflight
  cv_message = lv_message
  EXCEPTIONS
  failed = 1
  OTHERS = 2.
  IF sy-subrc <> 0.
  WRITE: / 'Errors occured while mapping json to abap'.
  ELSE.
  WRITE: / 'Fields SFLIGHT read from json:'.

• write all cols of this structure
  write_struc ls_sflight 15.
  ENDIF.
  ENDIF.