CODEWITHSUNDEEP
javastringfilesplitbufferedreader
Omar Fayez
Omar Fayez

Reputation: 103

How to to add values from a file into an array using split?

I have the following code:

BufferedReader metaRead = new BufferedReader(new FileReader(metaFile));
String metaLine = "";
String [] metaData = new String [100000];

while ((metaLine = metaRead.readLine()) != null){
    metaData = metaLine.split(",");
    for (int i = 0; i < metaData.length; i++)
        System.out.println(metaData[0]);
}

This is what's in the file:

testTable2  Name    java.lang.Integer   TRUE    test
testTable2  age     java.lang.String    FALSE   test
testTable2  ID      java.lang.Integer   FALSE   test

I want the array to have at metaData[0] testTable2, metaData[1] would be Name, but when I run it at 0 I get testtable2testtable2testtable2, and at 1 I'd get NameageID and OutOfBoundsException.

Any ideas what to do in order to get the result I want?

Upvotes: 3

Views: 55

Answers (3)

Minh
Minh

Reputation: 424

Although my answer may not fit completely with your question. But as i can see, your file format is TSV or CSV. May be you should consider using OpenCSV for your problem.

The library will handle reading, splitting process for you.

Upvotes: 0

Andrew
Andrew

Reputation: 49606

Just print metaData[i] instead of metaData[0] and split each string by "[ ]+" (that means "1 or more spaces"):

metaData = metaLine.split("[ ]+");

As a result, you will get the following arrays:

[testTable2, Name, java.lang.Integer, TRUE, test]
[testTable2, age, java.lang.String, FALSE, test]
[testTable2, ID, java.lang.Integer, FALSE, test]

The code snippet to the preceding output results:

while ((metaLine = metaRead.readLine()) != null) {
    metaData = metaLine.split("[ ]+");
    for (int i = 0; i < metaData.length; i++)
        System.out.print(metaData[i] + " ");
    System.out.println();
}

Also, I've written your task by using Java 8 and Stream API:

List<String> collect = metaRead
            .lines()
            .flatMap(line -> Arrays.stream(line.split("[ ]+")))
            .collect(Collectors.toList());

And, finally, there is the most straight-forward way:

final int LINES, WORDS;
String[] metaData = new String[LINES = 5 * (WORDS = 3)]; // I don't like it

int i = 0;
while ((metaLine = metaRead.readLine()) != null) {
    for (String s : metaLine.split("[ ]+")) metaData[i++] = s;
}

Upvotes: 3

Geeth Lochana
Geeth Lochana

Reputation: 164

Correct your code following line inside the for loop,

System.out.println(metaData[0]);

As 

System.out.println(metaData[i]);

Upvotes: 0

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