读取错误的 CSV 文件并将“坏行”打印到另一个文件 Java

Question

So my assignment is to read a csv file containing 'employee' objects. This file contains errors within it, for example a normal csv line should read:

EmployeeId,FirstName,LastName,DOB,Gender,Position

Some lines of the file however are either in the wrong format or contain null values. Eg:

9658273,bad

I need to be able to read the file and use exceptions to identify where the errors occur and write these 'bad lines' to a new file called bad.txt .

I am unsure where to start at this point and need some direction. I know how to read a file that has no errors but I'm having trouble writing exceptions.

Answer 1

So the first thing you should look at is what constitutes a 'bad line'. Write up some if statements for this:

For example (this is just logic/pseudocode):

if i have a null line:
write this line into the error file
else if i have a line with first name before employeeid:
write this line into the error file
etc, etc

You will need to figure out how to tell when a entry is out of order, which will probably be looking at types. For instance, name should not be a date/time. While Gender should not be an ID of 1028473AA848737.

Don't worry too much about writing the error into error.txt for now. Start with a simple:

if i detect an error: 
print out "ERROR DETECTED" 

then once you have a case where you can see you are detecting the errors correctly, you can move onto writing them to a file.

Hope this might give you something to start off: Let me know if you need further guidance :)

Answer 2

You can see: https://www.mkyong.com/java/how-to-read-and-parse-csv-file-in-java/ to read data, then validate them