How to append a string from a file to a string???????????

Question

hi there
the following code reads a line from a file,
while (true)
try
line = br.readLine();
catch (IOException e)
System.out.println("Error reading data file");
System.exit(1);
if (line == null) break;
st = new StringTokenizer(line, delimiterString);
n = st.countTokens();
if (first == 0) first = n;
if (n != first)
System.out.println("Data format error!");
System.exit(1);
how will i append the line to itself each time the loop runs? the line should contain all the lines in the file, not just a single line. thank you

Answer 1

You can make a StringBuffer object with the same scope as the line String and keep appending to the StringBuffer. You can use StringBuffer's toString() method to get a String back when you need it. You can also do this with a String instead of a StringBuffer using +=, but the String buffer is a lot more efficient.
StringBuffer wholeFile = new StringBuffer();
while (true)
try
line = br.readLine();
wholeFile.append(line);  // or put this wherever it makes most sense
catch (IOException e)
System.out.println("Error reading data file");
System.exit(1);
if (line == null) break;
st = new StringTokenizer(line, delimiterString);
n = st.countTokens();
if (first == 0) first = n;
if (n != first)
System.out.println("Data format error!");
System.exit(1);
}