CODEWITHSUNDEEP
javatext-parsing
Ebad Saghar
Ebad Saghar

Reputation: 1127

How to read lines from a file that has commas and semi colons in Java

I am aware that I can use File Reader class. But I am confused on the implementation when it comes to reading separate sections of text within a line.

Each line in the file will have names (first and last name separated by an empty space), but a comma is used to delimited the UKNOWN set of full names. A semicolon is then used to to separate the section within the line. The next section is consisted of names of streets (each street name is delimited by a comma as well).

What I want to do is read the full names into an ArrayList of strings, when the semicolon is reached, the street names should be inserted into a separate ArrayList of strings.

If I could get a brief example of how to go on about the implementation, I could the entire thing on my own.

NOTE: It must read from a text file. Each line will be a separate test case of full names, and street names.

EDIT:

Here is a sample of the input: James Cooper ,John Evans,Abe Lincoln;Jackson st,No way,Aspen Way

Output: The array list of names holds = James Cooper , John Evans, Abe Lincoln (each separated by commas)

The array list of street names holds = Jackson st,No way,Aspen Way (each separated by commas)

Upvotes: 1

Views: 6944

Answers (3)

Kazagha
Kazagha

Reputation: 36

If you don't mind introducing an extra dependency have a look at OpenCSV (http://opencsv.sourceforge.net/).

This is a pretty basic example that reads a line (called 'nextLine'), then adds each element in to the dataArray. This changes to a new line when it calls reader.readNext(). If you were sure that there are only two lines of data you could replace the 'while' statement and hard-code the names array first, call readNext() then the street names array. 

    //Create the ArrayList to hold data
    ArrayList<String> dataArray =  new ArrayList<String>(); 

    //openCSV reader to parse the CSV file
    CSVReader reader = new CSVReader(new FileReader(f));

    //nextLine array contains a an entire row of data,
    //Each element represents a cell in the spreadsheet.
    String[] nextLine;

    //Iterate though the CSV while there are more lines to read
    while((nextLine = reader.readNext()) != null)
    {
                    //Iterate through the elements on this line
        for(String s : nextLine)
        {
            dataArray.add(s);
        }
    }

Source: http://opencsv.sourceforge.net/#how-to-read

-Kaz

Upvotes: 0

Sourabh Bhat
Sourabh Bhat

Reputation: 1893

The Scanner class is good enough for all of this. You have to use the method useDelimiter() appropriately, depending on the delimiter (i.e. separating character/string) you want to use.

Upvotes: 0

trutheality
trutheality

Reputation: 23465

The easiest thing to do is probably to read the entire line into a String and then use String's split() a bunch of times.

String line; // Put the line in here however you're reading from the file.
String[] sections = line.split(";");
// Assuming you know there are always two sections, names and addresses:
String[] names = sections[0].split(",");
String[] addresses = sections[1].split(",");

// Convert arrays into ArrayLists if you actually need to
List<String> namesList = new ArrayList<>( Arrays.asList( names ) );
List<String> addressList = new ArrayList<>( Arrays.asList( addresses ) );

Upvotes: 3

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