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Making bufferedreader from loop, to next line?

sorry about the poor title, didn't quite know what to call it!
basically I made the loop below to show the first six lines from the file, got that sorted. When it comes to showing the six lines though, I'm not sure how to get them to appear on a different line each time. The closest I got, was including the joptionpane in the loop, showing one line, then on the next joptionpane on the next et al. The second joptionpane at the bottom shows all the lines but on the same line instead of the next etc. How ought I make it so they appear on the next line each time? \n doesn't seem to work.
private static void doOptionTwo(int balance) throws IOException {
JOptionPane.showMessageDialog(null, "Option two selected ");
String sum = null;
BufferedReader br = null;
br = new BufferedReader(new FileReader("file1.txt"));
for (int i = 1; i <= 6; i++){
String line1 = br.readLine();
//JOptionPane.showMessageDialog(null, line1);
sum = sum + line1;
}
if (br != null)br.close();
String log = sum;
JOptionPane.showMessageDialog(null, log);
}

Use StringBuilder instead of String which is initialized as null. You could do whatever you want with following code:
StringBuilder stringBuilder = new StringBuilder();
String newLineCharacter = System.getProperty("line.separator");
for (int i = 1; i <= 6; i++){
stringBuilder.append(br.readLine());
stringBuilder.append(newLineCharacter);//note: will add new line at end as well..
}

Just insert break each time in your String :
for (int i = 1; i <= 6; i++) {
String line1 = br.readLine();
sum += line1 + "\n";
}

You can just add "\n" between the lines.
String sum = "";
for (int i = 1; i <= 6; i++){
String line1 = br.readLine();
sum += line1 + "\n";
}
Or more appropriately, use a StringBuilder.
StringBuilder sb = new StringBuilder();
for (int i = 1; i <= 6; i++){
String line1 = br.readLine();
if (sb.length() > 0) {
sb.append('\n');
}
sb.append(line1);
}
String sum = sb.toString();

This is more efficient :
JOptionPane.showMessageDialog(null, "Option two selected ");
StringBuilder build = new StringBuilder();
BufferedReader br = null;
br = new BufferedReader(new FileReader("file1.txt"));
for (int i = 1; i <= 6; i++){
String line1 = br.readLine();
//JOptionPane.showMessageDialog(null, line1);
build.append(sum).append("\n");
}
if (br != null)br.close();
System.out.println(build.toString());

java.util.NoSuchElementException: No line found*

I keep getting this error
java.util.NoSuchElementException No line found
when I use this method
public boolean hasMoreCommands() {
if (input.hasNextLine()) {
return true;
} else {
//input.close();
return false;
}
}
public void advance() {
String str;
if(hasMoreCommands() == true){
do {
str = input.nextLine().trim();
// Strip out any comments
if (str.contains("//")) {
str = (str.substring(0, str.indexOf("//"))).trim();
}
} while (str.startsWith("//") || str.isEmpty() || hasMoreCommands());
command = str;
}
}
I have main code here:
public class Ptest
{
public Ptest(String fileName)
{
String line = null;
String nName = fileName.replace(".vm", ".asm");
Parser p = new Parser();
try{
File neF = new File(nName);
if(!neF.exists()){
neF.createNewFile();
}
File tempFile = new File("temp.txt");
if(!tempFile.exists()){
tempFile.createNewFile();
}
FileReader fr = new FileReader(fileName);
BufferedReader br = new BufferedReader(fr);
FileWriter fw = new FileWriter(nName);
BufferedWriter bw = new BufferedWriter(fw);
FileWriter writR = new FileWriter(tempFile);
BufferedWriter buffR = new BufferedWriter(writR);
while((line = br.readLine()) != null) {
buffR.write(line+ "\n");
//System.out.println(line);
}
buffR.flush();
buffR.close();
p.insertTitle(tempFile);
String ctype = p.commandType();
int len = ctype.length();
int spaces = 13 - len;
String sp = " ";
String asp = " ";
String a1 = null;
int a2;
int alen;
boolean t = false;
while(p.hasMoreCommands()){
for(int i= 0; i < spaces; i++){
sp += " ";
}
t = p.hasMoreCommands();
a1 = p.arg1();
alen = (10 - a1.length());
for(int i= 0; i < alen; i++){
asp += " ";
}
//a2 = p.arg2();
if (ctype == "C_PUSH" || ctype == "C_POP" || ctype == "C_FUNCTION" || ctype == "C_CALL") {
a2 = p.arg2();
bw.write(ctype + sp + a1 + asp + a2);
}
else {
bw.write(ctype + sp + a1);
}
p.advance();
ctype = p.commandType();
len = ctype.length();
spaces = 13 - len;
}
bw.flush();
bw.close();
}
catch(FileNotFoundException ex){
System.out.println("File not found!");
}
catch(IOException ex){
System.out.println("Error reading file '" + fileName + "'");
}
}
}
I went through debugger and it literally goes the entire file then gives me an error when its finished.

Like #hfontanez I think your problem is in this code:
if(hasMoreCommands() == true){
do {
str = input.nextLine().trim();
// Strip out any comments
if (str.contains("//")) {
str = (str.substring(0, str.indexOf("//"))).trim();
}
} while (str.startsWith("//") || str.isEmpty() || hasMoreCommands());
command = str;
}
However, my solution is to change the while clause to while (str.isEmpty() && hasMoreCommands());
I'm assuming that "advance" ought to return the next non-comment / blank line.
If the string from the previous pass is empty (after stripping any comment) it will go round the loop again provided that wasn't the last line. But, if that was the last line or str still has something in it, then it will exit the loop. Comments should have been stripped so don't need tested for in the while.
I think if you just test for hasNextLine within the loop then it will never exit the loop if the last line was comment / blank.

My guess is that your problem is here:
if(hasMoreCommands() == true){
do {
str = input.nextLine().trim();
// Strip out any comments
if (str.contains("//")) {
str = (str.substring(0, str.indexOf("//"))).trim();
}
} while (str.startsWith("//") || str.isEmpty() || hasMoreCommands());
command = str;
}
The exception you encountered (NoSuchElementException) typically occurs when someone tries to iterate though something (String tokens, a map, etc) without checking first if there are any more elements to get. The first time the code above is executed, it checks to see if it has more commands, THEN it gets in a loop. The first time it should work fine, however, if the test done by the while() succeeds, the next iteration will blow up when it tries to do input.nextLine(). You have to check is there is a next line to be got before calling this method. Surround this line with an if(input.hasNextLine()) and I think you should be fine.

Split file having Integers and string into strings only

i have the file which has data stored as " Integer-> \t(tab)-> String ->couple of space-> ".
Am I doing Wrong?
What I am doing is.
Trie t = new Trie();
BufferedReader bReader = new BufferedReader(new FileReader(
"H:\\100kfound.txt"));
String line;
String[] s = null;
while ((line = bReader.readLine()) != null) {
s = line.split("\t");
}
int i;
for (i = 0; i < s.length; i++) {
System.out.println(s[i]);
if (!(s[i].matches("\\d+"))) {
t.addWord(s[i]);
System.out.println(s[i]);
}
}
What I can see by debugging it is going properly till while loop but in for loop it just stores two strings and prints the same.

You might want to and a ^[0-9]+$ for the expressions so you just get complete integers. Without the ^ and $ you could be matching other characters like tt55gh would match.
if (!(s[i].matches("^[0-9]+$"))) {
}
Per the comment above you need to move the for loop inside the while loop.
while ((line = bReader.readLine()) != null) {
s = line.split("\t");
for (int i = 0; i < s.length; i++) {
System.out.println("Value "+i+": "+s[i]);
if (!(s[i].matches("^[0-9]+$"))) {
t.addWord(s[i]);
System.out.println("Integer "+i+": "+s[i]);
}
}
}

Java Reading 2D array in from file, numbers separated by comma

This is some code that I found to help with reading in a 2D Array, but the problem I am having is this will only work when reading a list of number structured like:
73
56
30
75
80
ect..
What I want is to be able to read multiple lines that are structured like this:
1,0,1,1,0,1,0,1,0,1
1,0,0,1,0,0,0,1,0,1
1,1,0,1,0,1,0,1,1,1
I just want to essentially import each line as an array, while structuring them like an array in the text file.
Everything I have read says to use scan.usedelimiter(","); but everywhere I try to use it the program throws straight to the catch that replies "Error converting number". If anyone can help I would greatly appreciate it. I also saw some information about using split for the buffered reader, but I don't know which would be better to use/why/how.
String filename = "res/test.txt"; // Finds the file you want to test.
try{
FileReader ConnectionToFile = new FileReader(filename);
BufferedReader read = new BufferedReader(ConnectionToFile);
Scanner scan = new Scanner(read);
int[][] Spaces = new int[10][10];
int counter = 0;
try{
while(scan.hasNext() && counter < 10)
{
for(int i = 0; i < 10; i++)
{
counter = counter + 1;
for(int m = 0; m < 10; m++)
{
Spaces[i][m] = scan.nextInt();
}
}
}
for(int i = 0; i < 10; i++)
{
//Prints out Arrays to the Console, (not needed in final)
System.out.println("Array" + (i + 1) + " is: " + Spaces[i][0] + ", " + Spaces[i][1] + ", " + Spaces[i][2] + ", " + Spaces[i][3] + ", " + Spaces[i][4] + ", " + Spaces[i][5] + ", " + Spaces[i][6]+ ", " + Spaces[i][7]+ ", " + Spaces[i][8]+ ", " + Spaces[i][9]);
}
}
catch(InputMismatchException e)
{
System.out.println("Error converting number");
}
scan.close();
read.close();
}
catch (IOException e)
{
System.out.println("IO-Error open/close of file" + filename);
}
}

I provide my code here.
public static int[][] readArray(String path) throws IOException {
//1,0,1,1,0,1,0,1,0,1
int[][] result = new int[3][10];
BufferedReader reader = new BufferedReader(new FileReader(path));
String line = null;
Scanner scanner = null;
line = reader.readLine();
if(line == null) {
return result;
}
String pattern = createPattern(line);
int lineNumber = 0;
MatchResult temp = null;
while(line != null) {
scanner = new Scanner(line);
scanner.findInLine(pattern);
temp = scanner.match();
int count = temp.groupCount();
for(int i=1;i<=count;i++) {
result[lineNumber][i-1] = Integer.parseInt(temp.group(i));
}
lineNumber++;
scanner.close();
line = reader.readLine();
}
return result;
}
public static String createPattern(String line) {
char[] chars = line.toCharArray();
StringBuilder pattern = new StringBuilder();;
for(char c : chars) {
if(',' == c) {
pattern.append(',');
} else {
pattern.append("(\\d+)");
}
}
return pattern.toString();
}

The following piece of code snippet might be helpful. The basic idea is to read each line and parse out CSV. Please be advised that CSV parsing is generally hard and mostly requires specialized library (such as CSVReader). However, the issue in hand is relatively straightforward.
try {
String line = "";
int rowNumber = 0;
while(scan.hasNextLine()) {
line = scan.nextLine();
String[] elements = line.split(',');
int elementCount = 0;
for(String element : elements) {
int elementValue = Integer.parseInt(element);
spaces[rowNumber][elementCount] = elementValue;
elementCount++;
}
rowNumber++;
}
} // you know what goes afterwards

Since it is a file which is read line by line, read each line using a delimiter ",".
So Here you just create a new scanner object passing each line using delimter ","
Code looks like this, in first for loop
for(int i = 0; i < 10; i++)
{
Scanner newScan=new Scanner(scan.nextLine()).useDelimiter(",");
counter = counter + 1;
for(int m = 0; m < 10; m++)
{
Spaces[i][m] = newScan.nextInt();
}
}

Use the useDelimiter method in Scanner to set the delimiter to "," instead of the default space character.
As per the sample input given, if the next row in a 2D array begins in a new line, instead of using a ",", multiple delimiters have to be specified.
Example:
scan.useDelimiter(",|\\r\\n");
This sets the delimiter to both "," and carriage return + new line characters.

Why use a scanner for a file? You already have a BufferedReader:
FileReader fileReader = new FileReader(filename);
BufferedReader reader = new BufferedReader(fileReader);
Now you can read the file line by line. The tricky bit is you want an array of int
int[][] spaces = new int[10][10];
String line = null;
int row = 0;
while ((line = reader.readLine()) != null)
{
String[] array = line.split(",");
for (int i = 0; i < array.length; i++)
{
spaces[row][i] = Integer.parseInt(array[i]);
}
row++;
}
The other approach is using a Scanner for the individual lines:
while ((line = reader.readLine()) != null)
{
Scanner s = new Scanner(line).useDelimiter(',');
int col = 0;
while (s.hasNextInt())
{
spaces[row][col] = s.nextInt();
col++;
}
row++;
}
The other thing worth noting is that you're using an int[10][10]; this requires you to know the length of the file in advance. A List<int[]> would remove this requirement.

Counting the number of characters from a text file

I currently have the following code:
public class Count {
public static void countChar() throws FileNotFoundException {
Scanner scannerFile = null;
try {
scannerFile = new Scanner(new File("file"));
} catch (FileNotFoundException e) {
}
int starNumber = 0; // number of *'s
while (scannerFile.hasNext()) {
String character = scannerFile.next();
int index =0;
char star = '*';
while(index<character.length()) {
if(character.charAt(index)==star){
starNumber++;
}
index++;
}
System.out.println(starNumber);
}
}
I'm trying to find out how many times a * occurs in a textfile. For example given a text file containing
Hi * My * name *
the method should return with 3
Currently what happens is with the above example the method would return:
0
1
1
2
2
3
Thanks in advance.

Use Apache commons-io to read the file into a String
String org.apache.commons.io.FileUtils.readFileToString(File file);
And then, use Apache commons-lang to count the matches of *:
int org.apache.commons.lang.StringUtils.countMatches(String str, String sub)
Result:
int count = StringUtils.countMatches(FileUtils.readFileToString(file), "*");
http://commons.apache.org/io/
http://commons.apache.org/lang/

Everything in your method works fine, except that you print the count per line:
while (scannerFile.hasNext()) {
String character = scannerFile.next();
int index =0;
char star = '*';
while(index<character.length()) {
if(character.charAt(index)==star){
starNumber++;
}
index++;
}
/* PRINTS the result for each line!!! */
System.out.println(starNumber);
}

int countStars(String fileName) throws IOException {
FileReader fileReader = new FileReader(fileName);
char[] cbuf = new char[1];
int n = 0;
while(fileReader.read(cbuf)) {
if(cbuf[0] == '*') {
n++;
}
}
fileReader.close();
return n;
}

I would stick to the Java libraries at this point, then use other libraries (such as the commons libraries) as you become more familiar with the core Java API. This is off the top of my head, might need to be tweaked to run.
StringBuilder sb = new StringBuilder();
FileReader fr = new FileReader(file);
BufferedReader br = new BufferedReader(fr);
String s = br.readLine();
while (s != null)
{
sb.append(s);
s = br.readLine();
}
br.close(); // this closes the underlying reader so no need for fr.close()
String fileAsStr = sb.toString();
int count = 0;
int idx = fileAsStr('*')
while (idx > -1)
{
count++;
idx = fileAsStr('*', idx+1);
}