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Array Lists, reading in from file and 2 Classes

I'm learning arraylists, I'm unsure of how to read in from file and add it to a list as I am much more used to arrays, are they alike?
I'm also getting many errors when I am trying to instantiate the class object 'film' but never mind about it.
How am I able to get load my file method working? To me it looks right I think I just need a strangers pov.
Also getting an error when trying to find the file symbol. If there is any specific readings I should do for array lists could you please link me or explain best you can.
I'm very new to both coding and stack overflow so if you could dumb anything down and please be patient if I don't understand anything thanks.
import java.util.*;
public class CinemaDriver {
film[] Film;
public static void main(String[] args) {
Film = new film[100];
ArrayList <Film> list = new ArrayList<Film> ();
}
public void readFromFile() {
File f = new file("file.txt");
Scanner infile = new Scanner(f);
int x = infile.nextInt();
for(int i = 0; i < x ; i++) {
String title = infile.nextLine();
String genre = infile.nextLine();
int screenings = infile.nextInt();
int attendance = infile.nextInt();
file.nextLine();
list.add(title,genre,screenings,name);
}
infile.close();
}
public void displayAll() {
for (film f : list ){
System.out.println(f +"/ \n");
}
}
}

Your ArrayList keeps Film objects as defined here:
ArrayList <Film> list = new ArrayList<Film> ();
But you are trying to insert several different objects or values (Strings, ints, etc...) instead of a Film object
list.add(title,genre,screenings,name);
What you should do is something like this:
Option 1:
list.add(new Film(title,genre,screenings,name));
Option2:
Film f = new Film();
f.setTitle(title);
f.setGenre(genre);
f.setScreenings(screenings);
f.setName(name);
list.add(f);

How do I add / delete a line from a text file?

I am unsure on how to give the user an option to add / delete a name from the existing text file. The current code works fine and reads in names from the text file. Could someone give me a hand on this?
import java.io.File;
import java.util.Scanner;
public class AddOrDeleteNames {
public static void main(String[] args) throws Exception {
String[] names = new String[100];
Scanner scan = new Scanner(new File("names.txt"));
int index = 0;
while (scan.hasNext()){
names[index]=(scan.nextLine());
index++;
}
for(int i = 0; i < index; i++){
System.out.println(names[i]);
}
scan.close();
}
}

It is possible, almost everything is, but you'll find it very difficult to do using arrays.
I would instead use an ArrayList which is similar, but much, much better than just regular ol' arrays.
A String ArrayList is defined like so:
ArrayList<String> names = new ArrayList<String>();
You can add using the add function of the ArrayList:
while (scan.hasNext())
names.add(scan.nextLine());
Then, to remove a name from the text file, just remove it from the names ArrayList using the remove function, and write the modified ArrayList to the file:
names.remove("Some Name Here");
PrintWriter writer = new PrintWriter("names.txt", "UTF-8");
for (int i = 0; i < names.size(); i++)
writer.println(names.get(i));
writer.close();
Likewise, to add a new name to the file, just add the new name to the ArrayList before you write it to the file, using the add function

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.