package net.technearts.rip;
   
   import java.io.IOException;
   import java.io.InputStream;
   import java.io.OutputStream;
   import java.util.ArrayList;
   import java.util.Iterator;
   import java.util.List;
   
  import org.apache.poi.ss.usermodel.Cell;
  import org.apache.poi.ss.usermodel.Row;
  import org.apache.poi.ss.usermodel.Sheet;
  import org.apache.poi.ss.usermodel.Workbook;
  import org.apache.poi.xssf.usermodel.XSSFWorkbook;
  
  import com.fasterxml.jackson.core.JsonFactory;
  import com.fasterxml.jackson.core.JsonGenerator;
  
  public class RipExcelReader {
  
    public static RipExcelReader setIO(final InputStream in,
        final OutputStream out) throws IOException {
      final RipExcelReader result = new RipExcelReader();
      result.workbook = new XSSFWorkbook(in);
      result.out = out;
      return result;
    }
  
    private OutputStream out;
  
    private Workbook workbook;
  
    public RipExcelReader() {
  
    }
  
    public void read() {
      readSheet(workbook.getSheetAt(0));
    }
  
    public void readSheet(final Sheet sheet) {
      final JsonFactory factory = new JsonFactory();
  
      try (JsonGenerator generator = factory.createGenerator(out)) {
        generator.writeStartObject();
        generator.writeArrayFieldStart(sheet.getSheetName());
        final Iterator<Row> i = sheet.rowIterator();
        Row r;
        r = i.next();
        Cell header;
        final List<String> headers = new ArrayList<>();
        int col = 0;
        while ((header = r.getCell(col++)) != null) {
          headers.add(header.getStringCellValue());
        }
        while (i.hasNext()) {
          r = i.next();
          generator.writeStartObject();
          col = 0;
          for (final String key : headers) {
            generator.writeStringField(key, r.getCell(col++).toString());
  
          }
          generator.writeEndObject();
        }
        generator.writeEndArray();
        generator.writeEndObject();
      } catch (final IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
      }
    }
  
  }