parsing each line in text file java

Question

I have a text file that has the following lines:

150004|2012|12|15|0|0|3|0|0|-3.2411|83.9962|156.3321|1.1785|205.3125|2.0599
150004|2012|12|15|0|10|3|0|0|-3.4206|85.9575|150.4877|1.4142|226.7578|2.4276
150004|2012|12|15|0|20|3|0|0|-2.2696|86.2675|149.3848|2.1553|225.7031|3.4387

every '|' sign indicates it has a column. I have to extract the info from each line that is inside of '|' signs. When I try the following code:

File filer = new File("C:\\Users\\Ali Y. Akgul\\Desktop\\150004_15122012_G.txt");
        try (BufferedReader reader = new BufferedReader(new FileReader(filer))) {
            while (true) {
                String line = reader.readLine();
                if (line == null) {
                    break;
                }
                String[] fields = line.split("|");
                // process fields here
                for(int i=0;i<=fields.length;i++){
                    System.out.println(fields[i]);
                }
            }
        }
}

it gives me:

1
5
0
0
0
4
|
2
0
1
2
|
1
2
|
1
5
|
Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 76
0
|
0
|
3
|
0
|
0
|
-
3
.
2
4
    at testenv.TestEnv.main(TestEnv.java:31)
1
1
|
8
3
.
9
9
6
2
|
1
5
6
.
3
3
2
1
|
1
.
1
7
8
5
|
2
0
5
.
3
1
2
5
|
2
.
0
5
9
9
Java Result: 1

How can I parse it correctly?

tckmn · Accepted Answer · 2013-01-16 14:07:45Z

8

It is because that String.split uses a regex.

In regexes, the | character is a special character meaning either the pattern on the left OR on the right of the character. It has to be escaped with a backslash (\\)

The correct syntax is:

String[] fields = line.split("\\|");

Also, take nto that I didn't see the issue with the for loop, but that needs fixing too, that is why the ArrayOutOfBoundsException pops up its ugly head...

edited Jan 16, 2013 at 14:07

tckmn

59.7k27 gold badges118 silver badges156 bronze badges

answered Jan 16, 2013 at 14:00

ppeterka

20.8k6 gold badges67 silver badges80 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Adrián · Accepted Answer · 2013-01-16 14:06:13Z

5

for(int i=0;i<=fields.length;i++)

needs to be

for(int i=0;i<fields.length;i++)

(The '<=' must be '<')

Also the issue with your regexp pointed out in other answers.

edited Jan 16, 2013 at 14:06

answered Jan 16, 2013 at 14:00

Adrián

6,2651 gold badge29 silver badges49 bronze badges

Comments

Reimeus · Accepted Answer · 2013-01-16 14:00:20Z

3

| is a special character in regex which acts an OR operator, you'll need to escape the expression using:

String[] fields = line.split("\\|");

answered Jan 16, 2013 at 14:00

Reimeus

160k16 gold badges225 silver badges282 bronze badges

Comments

András Kerekes · Accepted Answer · 2013-01-16 14:00:29Z

3

Instead of for(int i=0;i<=fields.length;i++){ use for(int i=0;i<fields.length;i++){ so use < instead of <= in the condition.

answered Jan 16, 2013 at 14:00

András Kerekes

1,0017 silver badges13 bronze badges

1 Comment

András Kerekes Over a year ago

and consider to comment of @ppeterka

rtheunissen · Accepted Answer · 2013-01-16 14:35:43Z

2

Try this:

Path file = Paths.get("C:\\Users\\Ali Y. Akgul\\Desktop\\150004_15122012_G.txt");

ArrayList<String> lines = Files.readAllLines(file, Charset.defaultCharset());
ArrayList<String []> columns = new ArrayList<>();
for(String line : lines){
    columns.add(line.split('\|'));
}

// Now for each line you have columns.
for(String [] s : columns){ 
    System.out.println(Arrays.toString(s));
}

// To get only the values for column 8 onwards (in response to your comment)
for(String [] s : columns){ 
    String [] sublist = Arrays.copyOfRange(s, 8, s.length);
    System.out.println(Arrays.toString(sublist));
}

// To get only the columns from line 8 onwards
for(int i = 0; i < columns.size(); i++){
    System.out.println(Arrays.toString(columns.get(i)));
}

edited Jan 16, 2013 at 14:35

answered Jan 16, 2013 at 14:05

rtheunissen

7,4355 gold badges40 silver badges72 bronze badges

7 Comments

Ali Yucel Akgul Over a year ago

Thanks a lot for your solution. your solution gives like [150004, 2012, 12, 15, 0, 0, 3, 0, 0, -3.2411, 83.9962, 156.3321, 1.1785, 205.3125, 2.0599] [150004, 2012, 12, 15, 0, 10, 3, 0, 0, -3.4206, 85.9575, 150.4877, 1.4142, 226.7578, 2.4276] [150004, 2012, 12, 15, 0, 20, 3, 0, 0, -2.2696, 86.2675, 149.3848, 2.1553, 225.7031, 3.4387] Now how to get the columns from 8 to last?

rtheunissen Over a year ago

Do you want to drop the first 7 values of each array? Or do you want to drop the first 7 lines?

Ali Yucel Akgul Over a year ago

well I will use them too. but necessary part is from 8 to last. I have to assign such strings for each, so that I can save them on database.

Ali Yucel Akgul Over a year ago

I changed columns[i] to columns.get(i).toString() because it says array required but arraylist found. THrough my way it gives like [Ljava.lang.String;@6e677ea2 [Ljava.lang.String;@4caaf64e

Ali Yucel Akgul Over a year ago

nope it still says, array required but arraylist<String[]> found

|

Grimmy · Accepted Answer · 2013-01-16 14:01:32Z

2

It seems that you have a boundary issue in the following lines:

for(int i=0;i<=fields.length;i++){
   System.out.println(fields[i]);
}

should be

for(int i=0;i<fields.length;i++){
   System.out.println(fields[i]);
}

answered Jan 16, 2013 at 14:01

Grimmy

8266 silver badges16 bronze badges

Comments

Mihai · Accepted Answer · 2013-01-16 14:00:46Z

1

shoud be smaller than: for(int i=0;i<fields.length;i++)

answered Jan 16, 2013 at 14:00

Mihai

1213 bronze badges

Collectives™ on Stack Overflow

parsing each line in text file java

7 Answers 7

Comments

Comments

Comments

1 Comment

7 Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

7 Answers 7

Comments

Comments

Comments

1 Comment

7 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related