Creating bean of FileInputStream

Question

I need to write 3 different sheets in the same excel workbook in JAVA. I need to segregate this task to 3 different classes, each class should write one excel sheet in the same file. Now everytime at the end of a class, I need to flush the data to that particular sheet. Something like,

inputStream =new FileInputStream("FileName.xls");
wb_template = new XSSFWorkbook(inputStream);
inputStream.close();
wb = new SXSSFWorkbook(wb_template);

//Logic here

FileOutputStream out = new FileOutputStream("FileName.xls");
workbook.write(out);
    wb.dispose();
    out.close();

and repeat this common part of opening and closing in another class for another sheet.

Now, as my class is annotated with @Component annotation, I simply can not create FileOutputStream with new in my classes as the sample code above. So I need to create bean for them. So now my doubt is, how many beans do I need to create for each type. i.e FileInputStream, SXSSFWorkbook and FileOutputStream ? As I need to dispose workbook at end of every class and need to close FileOutputStream at end of every class, will single bean be sufficient ???

I am novice to this field. Any lead will be appreciated.

Answer 1

I don't think input and output streams are good candidates for Spring beans.
Much better and more intuitive candidates are your excel sheet writers:

interface ExcelSheetWriter {
    void writeOneSheet(String excelFileName);
}

@Configuration
class Config {
    @Bean(name="sheet1Writer) ExcelWriter getSheet1Writer() {
        return new Sheet1Writer(); //implements ExcelWriter
    }
}

class ExcelDocumentWriter {
    @Autowired @Qualifier("sheet1Writer") ExcelWriter sheet1Writer;
    @Autowired @Qualifier("sheet2Writer") ExcelWriter sheet2Writer;
    @Autowired @Qualifier("sheet3Writer") ExcelWriter sheet3Writer;
    //... use them to write the entire document
}

Good spring beans don't change state after initialization.