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Java File Parsing - Go word by word

I have a file content as Follows:
Sample.txt:
Hi my name is john
and I am an engineer. How are you
The output I want is an arrayList of string like [Hi,my,name,is,john,and,I,am,an,engineer,.,How,are,you]
The standard java function parses it as line and I would get an array containing the lines. I am confused as to which approach I should use to get the following output.
Any help is appretiated.

.nextLine() will get one whole line but .next() will go word by word

You could check out using the Scanner class with the .next() method.

This will read the file and collect all words into a list of strings.
Edit: Updated so as to handle punctuation and the likes as distinct words:
try {
List<String> words = Files.lines(Paths.get("/path/to/sample.txt"))
.map(line -> line.split("\\b"))
.flatMap(Arrays::stream)
.filter(w -> !w.trim().isEmpty())
.collect(Collectors.toList());
return words;
} catch (IOException e) {
// handle error
}

If you are getting the strings as whole lines, but just want the words, you could use .split(" ") on the words, as this would return an array containing individual words with no spaces. If you want to do this within the file reading, you could use something like the following...
public ArrayList<String> readWords(File file) throws IOException {
ArrayList<String> words = new ArrayList<String>();
String cLine = "";
BufferedReader reader = new BufferedReader(new FileReader(file));
while ((cLine = reader.readLine()) != null) {
for (String word : cLine.split(" ")) {words.add(word);}
}
reader.close();
return words;
}
which would return an ArrayList<String> containing all of the individual words in the file.
Hope this helps.

How to take StringTokenizer result to ArrayList in Java?

I want to take StringTokenizer result to ArrayList. I used following code and in 1st print statement, stok.nextToken() print the correct values. But, in second print statement for ArrayList give error as java.util.NoSuchElementException .
How I take these results to an ArrayList?
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.StringTokenizer;
public class Test {
public static void main(String[] args) throws java.io.IOException {
ArrayList<String> myArray = new ArrayList<String>();
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
System.out.print("Enter : ");
String s = br.readLine();
StringTokenizer stok = new StringTokenizer(s, "><");
while (stok.hasMoreTokens())
System.out.println(stok.nextToken());
// -------until now ok
myArray.add(stok.nextToken()); //------------???????????
System.out.println(myArray);
}
}

Quoting javadoc of StringTokenizer:
StringTokenizer is a legacy class that is retained for compatibility reasons although its use is discouraged in new code. It is recommended that anyone seeking this functionality use the split method of String or the java.util.regex package instead.
"New code" meaning anything written for Java 1.4 or later, i.e. ancient times.
The while loop will extract all values from the tokenizer. When you then call nextToken() after already having extracted all the tokens, why are you surprised that you get an exception?
Especially given this quote from the javadoc of nextToken():
Throws NoSuchElementException if there are no more tokens in this tokenizer's string.
Did you perhaps mean to do this?
ArrayList<String> myArray = new ArrayList<>();
StringTokenizer stok = new StringTokenizer(s, "><");
while (stok.hasMoreTokens()) {
String token = stok.nextToken(); // get and save in variable so it can be used more than once
System.out.println(token); // print already extracted value
// more code here if needed
myArray.add(token); // use already extracted value
}
System.out.println(myArray); // prints list

ArrayList<String> myArray = new ArrayList<String>();
while (stok.hasMoreTokens()){
myArray.add(stok.nextToken());
}
dont call stock.nextToken outside the while loop that results in exceptions and printing out arraylist in System.out.println wont help you have to use a for loop.
for(String s : myArray){
System.out.Println(s);
}

How to only get the lines you want from an arraylist depending on how they start, IN JAVA

I have a very long string containing GPS data but this is not important. What I need to do is separate the string which is in an arraylist (one big string) into multiple pieces.
The tricky part is that the string is made up of multiple 'gps sentances' and I only require two types of these sentences.
The types I need start with $GPSGSV and $GPSGGA. Basically I need to dump ONLY THESE sentences into another arraylist while leaving all the rest behind.
The new arraylist must be in line-by-line form so that each sentence is followed by a new line.
Each sentence also ends in one white space which could be helpful when splitting up. The arraylist data is shown below. - This is printed from the arraylist.
[$GPGSA,A,3,28,09,26,15,08,05,21,24,07,,,,1.6,1.0,1.3*3A,
$GPRMC,151018.000,A,5225.9627,N,00401.1624,W,0.11,104.71,210214,,*14,
$GPGGA,151019.000,5225.9627,N,00401.1624,W,1,09,1.0,38.9,M,51.1,M,,0000*72,
$GPGSA,A,3,28,09,26,15,08,05,21,24,07,,,,1.6,1.0,1.3*3A,
$GPGSV,3,1,12,26,80,302,44,09,55,063,40,05,53,191,39,08,51,059,37*79,
$GPGSV,3,2,12,28,43,112,34,15,40,284,42,21,18,305,33,07,18,057,27*7E,
$GPGSV,3,3,12,10,05,153,,24,05,234,38,18,05,318,22,19,05,035,*79,
$GPRMC,151019.000,A,5225.9627,N,00401.1624,W,0.10,105.97,210214,,*1D,
$GPGGA,151020.000,5225.9627,N,00401.1624,W,1,09,1.0,38.9,M,51.1,M,,0000*78,
$GPGSA,A,3,28,09,26,15,08,05,21,24,07,,,,1.6,1.0,1.3*3A,
$GPRMC,151020.000,A,5225.9627,N,00401.1624,W,0.12,105.18,210214,,*12,
$GPGSA,A,3,28,09,26,15,08,05,21,24,07,,,,1.6,1.0,1.3*3A,
$GPRMC,151021.000,A,5225.9626,N,00401.1624,W,0.11,99.26,210214,,*28,
$GPGGA,151022.000,5225.9626,N,00401.1623,W,1,09,1.0,38.9,M,51.1,M,,0000*7C,
$GPGSA,A,3,28,09,26,15,08,05,21,24,07,,,,1.6,1.0,1.3*3A,
$GPRMC,151022.000,A,5225.9626,N,00401.1623,W,0.11,109.69,210214,,*1F,
The data continues up to 2000 sentences.
Any help would be great. Thanks
EDITS ------
Looking back at what I have.. It may be best if I just read in the lines (as the file is formatted to be one sentence per line) which start with either the GSV or the GGA tag. In the buffered reader section of the method, how could I go about doing that? Here is some of my code ....
try {
File gpsioFile = new File(gpsFile);
FileReader file = new FileReader(gpsFile);
BufferedReader buffer = new BufferedReader(file);
StringBuffer stringbuff = new StringBuffer();
String ans;
while ((ans = buffer.readLine()) != null) {
gps.add(ans);
stringbuff.append(ans);
stringbuff.append("\n");
}
} catch (Exception e) {
e.printStackTrace();
}
From this could I get an Arraylist with just the GGA and GSV sentences/lines but in the same order that they were from the file?
Thanks

OK, I'd first start by splitting your string into individual lines with spilt():
String[] split = "$GPGSA,A,3,28,09,26,15,08,05,21,24,07,,,,1.6,1.0,1.3*3A,".split(",");
you can also use "\n" as a split delimiter instead of ",". This will give you an array over which you can iterate.
List<String> filtered = new ArrayList<String>()
for (String item, split) {
if (item.startsWith("$GPGSA")) {
filtered.add(item);
}
}
filtered would be a new Array with the items you want to keep.
This approach works with JDK 6+. In JDK 8, this kind of problem can be solved more elegantly with the stream API.

My understanding is that you've got an ArrayList with a single String element. That String is a comma separated list of values. So step one is to extract the string and split it into it's constituent parts. Once you've done that you can process the each item in turn.
private static List<List<String>> splitData(final ArrayList<String> data) {
final List<List<String>> filteredData = new ArrayList<List<String>>();
String fullText = data.get(0);
String[] splitData = fullText.split(",");
List<String> currentList = null;
for (int i = 0;i < splitData.length; i++) {
final String next = splitData[i];
if (startTags.contains(next)) {
if (interestingStartTags.contains(next)) {
currentList = new ArrayList<String>();
filteredData.add(currentList);
} else {
currentList = null;
}
}
if (currentList != null) {
currentList.add(next);
}
}
return filteredData;
}
The two static Set<String> provide the set of all 'gps sentence' start tags and also the set of ones you're interested in. The split data method uses startTags to determine if it has reached the start of a new sentence. If the new tag is also interesting, then a new list is created and added to the List<List<String>>. It is this list of lists that is returned.
If you don't know all of the strings you want to use as 'startTag' then you could next.startsWith("$GP") or similar.
Reading the file
Looking at the updated question of how to read the file you could remove the StringBuffer and instead simply add each line you read to an ArrayList. The code below will step over any lines that do not start with the two tags you are interested in. The order of the lines within lineList will match the order they are found in the file.
FileReader file = new FileReader(gpsFile);
BufferedReader buffer = new BufferedReader(file);
String ans;
ArrayList<String> lineList = new ArrayList<String>();
while ((ans = buffer.readLine()) != null) {
if (ans.startsWith("$GPSGSV")||ans.startsWith("$GPSGGA")) {
lineList.add(ans);
}
}

How to make a method for searching from array and print entire arraybox?

I could use some help with a part of a code I am working on.
I made a method which I think transformed every line of my .txt file into separate elements in an Array. However, I now want to be able to search in them and make the program print the entire element. ie: one of the lines reads: Crow, M, Kansas, june2012
I think I was able to make it into an array. Now I want to be able to search for "crow" and be able to get all the elements with that word in them printed alongside the rest of the String in the element.
The code I have so far:
System.out.println("Her kan du soke etter registrerigner etter fugletype");
try {
Scanner sc = new Scanner(new File("fugler.txt"));
List<String> lines = new ArrayList<String>();
while (sc.hasNextLine()) {
lines.add(sc.nextLine());
}
String[] arr = lines.toArray(new String[lines.size]);
}catch (Exception e) {
}

As others have already pointed out, you don't need to put your lines into an array since you already have them in an ArrayList.
If you want to "search" lines and only print certain ones you could use contains:
try {
Scanner sc = new Scanner(new File("fugler.txt"));
List<String> lines = new ArrayList<String>();
while (sc.hasNextLine()) {
lines.add(sc.nextLine());
}
for (String line : lines) {
if(line.contains("yourSearchString")) {
System.out.println(line);
}
}
} catch (Exception e) {
}

First of all, you don't need to put the lines in an array. You already have them in a list.
You could print them as they come in:
while (sc.hasNextLine() {
String currentLine = sc.nextLine();
System.out.println(currentLine);
lines.add(currentLine);
}
Or, you could just print all the lines in your list:
for (String line : lines) {
System.out.println(line);
}

In addition to the other problems, if you want to have an array, you should replace this:
String[] arr = lines.toArray(new String[0]);
with this:
String[] arr = lines.toArray(new String[lines.size()]);
Your array that gets passed in is the array that will be populated by toArray, so it needs to be big enough to hold all the elements.
If you want to search for some value line, you can use the original ArrayList<String>:
// returns the index of the element, ie. its zero-based line number
int index = lines.indexOf(line);
To print them all, just loop through them all:
for(String l : lines) {
System.out.println(l);
}

Regarding arrayList

I have used scanner instead of string tokenizer ,, below is the piece of code...
Scanner scanner = new Scanner("Home,1;Cell,2;Work,3");
scanner.useDelimiter(";");
while (scanner.hasNext()) {
// System.out.println(scanner.next());
String phoneDtls = scanner.next();
// System.out.println(phoneDtls);
ArrayList<String> phoneTypeList = new ArrayList<String>();
if(phoneDtls.indexOf(',')!=-1) {
String value = phoneDtls.substring(0, phoneDtls.indexOf(','));
phoneTypeList.add(value);
}
Iterator itr=phoneTypeList.iterator();
while(itr.hasNext())
System.out.println(itr.next());
}
The ouput I get upon executing this...
Home
Cell
Work
As it is seen from the above code is that in the array list phoneTypeList we are finally storing the values..but the logic of finding out the value on the basisi of ',' is not that much great..that is ..
if(phoneDtls.indexOf(',')!=-1) {
String value = phoneDtls.substring(0, phoneDtls.indexOf(','));
phoneTypeList.add(value);
}
could you please advise me with some other alternative ..!! to achieve the same thing...!!thanks a lot in advance..!!

Well, since you asked if there is another way to do it then here is an alternative: You can split the string directly and do it with less code with the foreach statement:
String input = "Home,1;Cell,2;Work,3";
String[] splitInput = input.split(";");
for (String s : splitInput ) {
System.out.println(s.split(",")[0]);
}
No need to use the ArrayList<T> since you can iterate over an array as well.

could you try to split based on ',' STIRNG_VALUE.split(','); will return u an array with strings separated with , may be this helps

If i understand correctly. The problem statement is you want to maintain a list of Phone-Type-List. Like this: ["Home", "Cell", "Work"].
I suggest you keep this in a property file / config file / database which ever makes sense and load it to memory on start of you app.
If the input cannot be changed then as for the algorithm i couldn't think of a better one. Looks good.
You could use split function of string if that makes sense.
First use split on ";"
Then a split on ","

declare the arraylist outside the while loop.
try this, i have made some change for better performance too. hope you can compare and understand the change.
ArrayList<String> phoneTypeList = new ArrayList<String>();
Scanner scanner = new Scanner("Home,1;Cell,2;Work,3");
scanner.useDelimiter(";");
String phoneDtls = null;
String value = null;
while (scanner.hasNext()) {
phoneDtls = scanner.next();
if (phoneDtls.indexOf(',') != -1) {
value = phoneDtls.split(",")[0];
phoneTypeList.add(value);
}
}
Iterator itr = phoneTypeList.iterator();
while (itr.hasNext())
System.out.println(itr.next());
I have executed n got the result, check screenshot.