How to read CSV from 2nd Line in java?

Question

I have a comma delimited CSV file ans I have the code to read it from 2nd line. But it gives me the following error. Exception in thread "AWT-EventQueue-0" java.lang.OutOfMemoryError: Java heap space

This is my Code.

public static List<String> readCSV(String path){        
    BufferedReader br = null;
    String[] cd = null;
    String line ="";
    String split=",";
    List<String> list = new ArrayList<String>();
    try {        
        br=new BufferedReader(new FileReader(path));            
        while ((line = br.readLine()) != null) {
            boolean firstLine = true;               
            while (line != null && line.startsWith("child's Last Name")) {
                if (firstLine) {
                    firstLine = false;
                    continue;
                } else {
                    list.add(line);
                }
            }               
        }               
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        if (br != null) {
            try {
                br.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    return list;
}

How can I fix it with this code..

Thanks in Advance!

Deepak Bhatia · Answer 1 · 2013-11-26T08:50:43.523

1

In your second while loop where are you assigning line again

 while (line != null && line.startsWith("child's Last Name"))

Once this condition is satisfied, you are not reassigning it.
Your code should be different something like,

boolean firstLine = true;               
while ((line = br.readLine()) != null) 
{
   if (firstLine) 
   {
      firstLine = false;
       continue;
   } 
   else if(line != null && line.startsWith("child's Last Name"))
   {
        list.add(line);
   }
}

edited Nov 26 '13 at 08:50

answered Nov 26 '13 at 08:45

Deepak Bhatia

6,230
2
24
58

The only place he re-assigns "line" is in the first while loop. – Ben Dale Nov 26 '13 at 08:48

score 0 · Answer 2 · edited May 23 '17 at 10:27

Usually, you get an out of memory error when you... well... run out of memory to run the application. Have you debugged into it? You could be stuck in an endless loop...

while (line != null && line.startsWith("child's Last Name")) {

Should this be an if statement?

EDIT:

while ((line = br.readLine()) != null) {

This really should be:

while(br.hasNext()) {

More info: Java - Read CSV with Scanner()

score 0 · Answer 3 · answered Nov 26 '13 at 08:45

Your problem has nothing to do with the 2nd line; You're simply trying to put the whole file in list and eventually, there's just too much to fit in memory. You have two choices:

Do not keep it all in memory! Process the line, do what you must, and don't store it, so it eventually gets garbage collected
If you really really must keep it all in memory, try increasing the amount of heap space available by starting java with a -Xmx parameter (run java -X for details)

UPDATE: oh oops, yes, as others said, you're also stuck in and endless loop. Consider this answer only once you've fixed that!

Scary Wombat · Accepted Answer · 2013-11-26T08:53:14.297

0

try

    br=new BufferedReader(new FileReader(path));            
    boolean firstLine = true;               
    while ((line = br.readLine()) != null) {
        if (line.startsWith("child's Last Name")) {
            if (firstLine) {
                firstLine = false;
                continue;
            } 
            list.add(line);
        }               
    }

There is no need for two while loops

edited Nov 26 '13 at 08:53

answered Nov 26 '13 at 08:46

Scary Wombat

44,617
6
35
64

score -1 · Answer 5 · answered Nov 26 '13 at 08:51

-1

try this..

    br=new BufferedReader(new FileReader(path)); 
    br.readLine();           
    while ((line = br.readLine()) != null) {
         if (line.startsWith("child's Last Name")) {
                 list.add(line);
         }               
    }

answered Nov 26 '13 at 08:51

subash

3,116
3
18
22

fails to account for skipping firstline – Scary Wombat Nov 26 '13 at 08:51

How to read CSV from 2nd Line in java?

5 Answers5