Question

I have 3 different types of files in a folder. Every file has same data which is saved into Employee Table.

File Types:

1. XML
2. Excel
3. .txt

I have written 3 separate classes which have two methods, take a filePath as String parameter and return an EmployeeVO Object or a List<EmployeeVO>.

I want to remove these if else.

List<EmployeeVO>  list ;
 if(fileName.endsWith(".xml")){
    list =   XmlReader();
 }else if(fileName.endsWith(".EXCEL")){
    list =     ExcelReader();
 }else if(fileName.endsWith(".TXT")){
    list =     TxtReader();
 }

Answer 1

You could use a kind of strategy:

// class field holding association from readers to extension
Map<String, Reader> readers = new HashMap<String, Reader>();

// configuration (bean initialization for example)
readers.put("xml", xmlReader);
readers.put("xls", excelReader);
readers.put("txt", txtReader);

// execution would be something like:
List<EmployeeVO> list = readers.get(fileExtension).readList();