我如何将我的 json 响应转换为 txt 制表符分隔的文件 rest api java？

Question

I have a sql query.

this is my abc.class

public class Abc {
    
    private Integer ABC_ID;
    private String RECIP_ID, RECIP_FIRST_NAME, RECIP_MIDDLE_NAME;
    
    public Abc() {
        //super();
        // TODO Auto-generated constructor stub
    }
    }

and the rest are the getters and setters;

    @RequestMapping(value = "/abc/export", method = RequestMethod.GET)
        @ResponseBody
        public ResponseEntity<List<abc>> getProviderExport(@RequestParam String id, HttpServletResponse response){
    
List<abc> abcdetails = jdbcTemplate.query(sqlQuery, new BeanPropertyRowMapper<abc>(abc.class));
HttpHeaders responseHeaders = new HttpHeaders();
        //responseHeaders.setContentType(MediaType.TEXT_PLAIN);
        String filename1 = "output.txt";
        //responseHeaders.setContentType("text/plain");
        response.setCharacterEncoding("UTF-8");
        responseHeaders.add("Content-Disposition","attachment; filename="+filename1);
        
        return new ResponseEntity<>(abcdetails, responseHeaders, HttpStatus.OK);

    }

when I execute the above code and run the api, my api prompts to save the output file as output.txt, but when i open the output file, the content is still in json format. can anyone help me on how to achieve the output.txt file that is using tab delimited and uppercase.

Answer 1

Because you return ResponseEntity<List<abc>> . A List<> is converted automatically to array JSON. You need to return a ResponseEntity<String> . So, convert your List<abc> to String .

Something like this :

final StringBuilder textData = new StringBuilder();
for (final Abc abcDetail : abcdetails) {
    final String line = abcDetail.getRECIP_FIRST_NAME() + " " + abcDetail.getRECIP_ID() + " ";//You can add your other field
    textData.append(line).append("\n");
}

return new ResponseEntity<>(textData.toString(), responseHeaders, HttpStatus.OK);

Answer 2

You have to convert that json format to text format using Jackson JSON Java Parser I am attaching a link for a brief example on how to convert jsno to txt file with tab delimited and uppercase.

Here is the link : https://www.journaldev.com/2324/jackson-json-java-parser-api-example-tutorial