how to read line by line and pass each line value to a method

[uma prem]

hi,

i have a text file, having one value in each line digitsandnumbers. now once i read it line by line i need to pass each lines value to one staticmethod (class ABC)which takes it as one of the parameter to get me one more id. Please help me,.i am in trouble.... Please help me with the correct code

what i have done so far is

public static ArrayList<String> getUUIDbyBID(String textFile)
	{
		
		String pathname=BOOKSG_PATH+"//cm:eBooks//cm:Complete/*";
    	String fieldname="";
    	String uuid="";
    	   	    			
		File file = new File(textFile);
		BufferedReader br = null;
		ArrayList<String> pidList=new ArrayList<String>();
		String text=null;
		try
		{
			
			br=new BufferedReader(new FileReader(file));
			while((text=br.readLine())!=null)
				
			{
				System.out.println(text);
				fieldname="+@\\:Identifier:\""+text+"\"";
				uuid=ABC.GetUIDByField(pathname,fieldname);//this is the method i need to pass my value 
				pidList.add(uuid);
				System.out.print("UUID :" +uuid);
										
			}
				
	}
		catch(FileNotFoundException e)
		{
			e.printStackTrace();
		}
		catch (IOException e)
		{	
		e.printStackTrace();
		}
		return pidList;
		
	}
}

thanks a lot for your time

[Joanne Neal]

TellTheDetails

[Campbell Ritchie]

I don't understand the problem. You obviously know how to write a method, so what you want is a method which takes the line and extracts the UUID from it. Your code already gives you half the method

public class ABC
{
    public static StringGetUIDByField(String pathname, String fieldname)
    {
        String uuid = . . . .;
        return uuid;
    }
 . . .
}

Obviously I don't know how to complete your method for you.

Why are you making all your methods static? Please put spaces before and after binary operators, after commas etc. Your code is hard to read as it stands.

[uma prem]

Hi Campbell,

Thanks for your reply,

My problem is :

My bidfilename is bid.txt having one value in each line(1000lines together)
Now in my program, I am passing the entire textfile(bid.txt) to the method, instead of one line at a time.I want help in that

fieldname="+@\\:Identifier:\""+text+"\"";
uuid=ABC.GetUIDByField(pathname,fieldname);//

like when I check in the fieldname parameter inside the method GetUIDbyField of class ABC,the fieldname shows +@\\:Identifier:\""+bid.txt(the entire filename) ,instead of +@\\:Identifier:\""+12134(one by one line value at a time)

hope i am clear of the problem facing

Please reply

[Sai Hegde]

fis = new FileInputStream(file);
bis = new BufferedInputStream(fis);
dis = new DataInputStream(bis);

// dis.available() returns 0 if the file does not have more lines.
while (dis.available() != 0) {
           System.out.println(dis.readLine());
}

[Campbell Ritchie]

Still don't understand the problem. What are you doing in that getUID method?

[Rob Spoor]

Sai Hegde wrote:

fis = new FileInputStream(file);
bis = new BufferedInputStream(fis);
dis = new DataInputStream(bis);

// dis.available() returns 0 if the file does not have more lines.
while (dis.available() != 0) {
           System.out.println(dis.readLine());
}

http://www.coderanch.com/how-to/java/AvailableDoesntDoWhatYouThinkItDoes

For files it's usually pretty accurate but that still doesn't guarantee that it works. If your disk is really busy then available() may return 0 even if there's still data available.

A BufferedReader wrapped around a FileReader seems like a better solution. The Javadoc of DataInputStream's readLine() method also suggests using BufferedReader for reading lines.

[Sai Hegde]

Nice, Rob! That is a valuable insight. Thanks!
@Campbell