Need MAJOR help with JAVA

[Xylitol]

Ok
Basically, my teacher assigned us this project and I've asked around my class for help but no one has finished it, so they are turning their projects in late.

I need help with it
This is what I need to do (not quoted) + This is only one of the 3 tasks that I have:

Find the # of times that a word appears in the text document
Anything with a dash between two words is one word
Anything with a space between two words is two words (such as twenty- seven)

I am supposed to use Scanner to open the text document (named lincoln.txt)
I believe that it is:
try
{
Scanner fin = new Scanner (new File(fname));
}
catch (FileNotFoundException e)
{
//missing something here
System.out.println ("File " + fname + " not found");
//missing something here
System.exit (1);
}

lincoln.txt:
The Gettysburg Address

Fourscore and seven years ago our fathers brought forth on
this continent a new nation, conceived in liberty, and dedicated to
the proposition that all men are created equal.

Now we are engaged in a great civil war, testing whether that
nation, or any nation so conceived and so dedicated, can long endure.
We are met on a great battlefield of that war. We have come to
dedicate a portion of that field as a final resting-place for those
who here gave their lives that the nation might live. It is altogether
fitting and proper that we should do this. But, in a larger sense, we
cannot dedicate, we cannot consecrate, we cannot hallow, this ground.
The brave men, living and dead, who struggled here have consecrated
it, far above our poor power to add or detract. The world will little
note, nor long remember, what we say here, but it can never forget
what they did here. It is for us the living, rather, to be dedicated
here to the unfinished work which they who fought here have thus far
so nobly advanced. It is rather for us to be here dedicated to the
great task remaining before us - that from these honored dead we take
increased devotion to that cause for which they gave the last full
measure of devotion - that we here highly resolve that these dead
shall not have died in vain - that this nation, under God, shall have
a new birth of freedom and that government of the people, by the
people, for the people, shall not perish from the earth.

I have to use ArrayLists in order to do this
However, I do not know how to use a loop to store each word into the list

I need desperate help with this project
Any help is welcomed

Thanks

 

[KLin]

Obligatory "do your own homework" response.

 

[AgaBoogaBoo]

Start by thinking how you would do it yourself if you had to find it, try to mimic that and then improve from there. Write out in words what you would do in simple english, then try to turn this into a flowchart, and finally into the program. It might seem a bit drawn out, but it will help you fully understand how to do it.

 

[George P Burdell]

Originally posted by: AgaBoogaBoo
Start by thinking how you would do it yourself if you had to find it, try to mimic that and then improve from there. Write out in words what you would do in simple english, then try to turn this into a flowchart, and finally into the program. It might seem a bit drawn out, but it will help you fully understand how to do it.

Agreed. Draw it out using paper/pencil if that works for you.

BTW, what's your major?

 

[Xylitol]

Originally posted by: George P Burdell

Originally posted by: AgaBoogaBoo
Start by thinking how you would do it yourself if you had to find it, try to mimic that and then improve from there. Write out in words what you would do in simple english, then try to turn this into a flowchart, and finally into the program. It might seem a bit drawn out, but it will help you fully understand how to do it.

Agreed. Draw it out using paper/pencil if that works for you.

BTW, what's your major?

I'm in highschool
I dont even know how to start with the loop to search

 

[paulney]

Ok, the task is rather simple.
Do you need to print out occurrence stats for each word encountered in text, or is the search word specified via an argument?

 

[Xylitol]

Originally posted by: paulney
Ok, the task is rather simple.
Do you need to print out occurrence stats for each word encountered in text, or is the search word specified via an argument?

the search word is my own idea to eventually print out the # of times that each word appears in the text document

Biggest thing that I need help for right now is
How to "traverse" the text document and store each word into an ArrayList so I can traverse that for the # of occurrences.

 

[George P Burdell]

Originally posted by: Xylitol

Originally posted by: George P Burdell

Originally posted by: AgaBoogaBoo
Start by thinking how you would do it yourself if you had to find it, try to mimic that and then improve from there. Write out in words what you would do in simple english, then try to turn this into a flowchart, and finally into the program. It might seem a bit drawn out, but it will help you fully understand how to do it.

Agreed. Draw it out using paper/pencil if that works for you.

BTW, what's your major?

I'm in highschool
I dont even know how to start with the loop to search

Didn't your teacher teach you anything? No textbook?

Oh what the hell, here is clue #1: StringTokenizer

As for loops, just google for or while loops in java and see what you get.

 

[Xylitol]

Originally posted by: George P Burdell

Originally posted by: Xylitol

Originally posted by: George P Burdell

Originally posted by: AgaBoogaBoo
Start by thinking how you would do it yourself if you had to find it, try to mimic that and then improve from there. Write out in words what you would do in simple english, then try to turn this into a flowchart, and finally into the program. It might seem a bit drawn out, but it will help you fully understand how to do it.

Agreed. Draw it out using paper/pencil if that works for you.

BTW, what's your major?

I'm in highschool
I dont even know how to start with the loop to search

Didn't your teacher teach you anything? No textbook?

Oh what the hell, here is clue #1: StringTokenizer

As for loops, just google for or while loops in java and see what you get.

I know how to use for/while loops (that much I learned from this teacher who in my class' opinion is meh)
I just dont know how to use the loops in a text document instead of an array/arrayList

We havent learned about StringTokenizers yet

 

[Xylitol]

hmmm could I do this?

StringTokenizer st = new StringTokenizer(lincoln.txt);
while (st.hasMoreTokens()) {
System.out.println(st.nextToken());
}

This would print out all of the words in individual lines
However, I still dont know how to transfer these words to an arrayList

 

[Evadman]

I could write that in about 60 seconds in VB. In fact, I will

Dim words() As String
Dim WordSorted() As String, WordCount() As Long
Dim alltext As String
Dim i As Long, a As Long
ReDim WordSorted(0)
ReDim WordCount(0)
alltext = "this is a test test test"
words() = Split(alltext, " ")
For i = 0 To UBound(words)
For a = 0 To UBound(WordSorted())
If UBound(WordSorted) = 0 Then 'add first word
ReDim Preserve WordSorted(UBound(WordSorted) + 1)
ReDim Preserve WordCount(UBound(WordCount) + 1)
WordSorted(UBound(WordSorted)) = words(i)
WordCount(a) = 1
ElseIf words(i) = WordSorted(a) Then
WordCount(a) = WordCount(a) + 1
ElseIf a = UBound(WordSorted) Then 'new word not in array
ReDim Preserve WordSorted(UBound(WordSorted) + 1)
ReDim Preserve WordCount(UBound(WordCount) + 1)
WordSorted(UBound(WordSorted)) = words(i)
WordCount(a) = 1
End If
Next a
Next i

For i = 1 To UBound(WordCount)
Debug.Print "the word '" & WordSorted(i) & "' appears " & WordCount(i) & " times" & vbCrLf
Next i

Sorry, no help in java, I don't know the syntax well enough to get it correct without an editer.

<edit>
had a 7 instead of a & in string concat.

 

[paulney]

Is ArrayList a mandatory class to use? Because it'll perform rather poorly for this task.
So, here's a pseudo-alg of what you do: (I didn't use generics, but you can add them if you want to avoid warnings in 1.5)

Hashtable myWords = new Hashtable();
Scanner scanner = new Scanner(new File("filename"));
while (scanner.hasNext()) {
String newToken = scanner.next();
if (myWord.containsKey(newToken)) {
int occurence = myWords.get(newToken);
occurence++;
myWords.put(newToken, occurence);
}
else {
myWords.put(newToken, 1);
}
}

That's the gist of it.
The default delimiter for scanner is whitespace, so you should be set.

After you exhaust all tokens, print out the contents of the Hashtable using enumeration

 

[paulney]

Originally posted by: George P Burdell
Didn't your teacher teach you anything? No textbook?

Oh what the hell, here is clue #1: StringTokenizer

As for loops, just google for or while loops in java and see what you get.

He mentioned Scanner, so my guess is they are using 1.5. He doesn't have to use StringTokenizer at all, that's old school.

 

[iotone]

What I Found on Google

 

[Xylitol]

Originally posted by: paulney
Is ArrayList a mandatory class to use? Because it'll perform rather poorly for this task.
So, here's a pseudo-alg of what you do: (I didn't use generics, but you can add them if you want to avoid warnings in 1.5)

Hashtable myWords = new Hashtable();
Scanner scanner = new Scanner(new File("filename"));
while (scanner.hasNext()) {
String newToken = scanner.next();
if (myWord.containsKey(newToken)) {
int occurence = myWords.get(newToken);
occurence++;
myWords.put(newToken, occurence);
}
else {
myWords.put(newToken, 1);
}
}

That's the gist of it.
The default delimiter for scanner is whitespace, so you should be set.

After you exhaust all tokens, print out the contents of the Hashtable using enumeration

Unfortunately, the teacher said that the only classes we can use for that type of stuff are: ArrayLists and Arrays (Since they're the only ones that we have learned so far - Any others and he said we would receive a 50% deduction )

I'm researching hashtables right now on sun java so I can get the gist of what you're doing

 

[paulney]

Originally posted by: Xylitol

Originally posted by: paulney
Is ArrayList a mandatory class to use? Because it'll perform rather poorly for this task.
So, here's a pseudo-alg of what you do: (I didn't use generics, but you can add them if you want to avoid warnings in 1.5)

Hashtable myWords = new Hashtable();
Scanner scanner = new Scanner(new File("filename"));
while (scanner.hasNext()) {
String newToken = scanner.next();
if (myWord.containsKey(newToken)) {
int occurence = myWords.get(newToken);
occurence++;
myWords.put(newToken, occurence);
}
else {
myWords.put(newToken, 1);
}
}

That's the gist of it.
The default delimiter for scanner is whitespace, so you should be set.

After you exhaust all tokens, print out the contents of the Hashtable using enumeration

Unfortunately, the teacher said that the only classes we can use for that type of stuff are: ArrayLists and Arrays (Since they're the only ones that we have learned so far - Any others and he said we would receive a 50% deduction )

I'm researching hashtables right now on sun java so I can get the gist of what you're doing

Ugh. Ok. That seems odd, but maybe you guys aren't ready for associative collections. Basically, a Hashtable associates a value to a key, so a lookup of any value by its key happens in the same amount of time O(1) whatever the key is. They keys here are your tokens, and the values - number of occurrences in the text.

In order to use ArrayLists, you'll have to run through the list each time you get a token to find if you have already seen it or not. That will slow down your code incredibly (you are now running O(n) operation instead of O(1), where n is the number of tokens you've seen so far, for each new token).

So, the code would look like this:

ArrayList myWords = new ArrayList();
ArrayList occurences = new ArrayList();

Scanner scanner = new Scanner(new File("filename"));
while (scanner.hasNext()) {
String newToken = scanner.next();
boolean tokenFound = false;
int tokenIndex = -1;
int currPos = 0;

while (!tokenFound && currPos < myWords.size()) {
if (myWords[currPos].equals(newToken) {
tokenFound = true;
tokenIndex = currPos;
}
currPos++;
}

if (tokenFound) {
occurences[tokenIndex]++; // check if Integer supports ++ op, I don't remember
}
else {
myWords.add(newToken);
occurences.add(new Integer(0));
}
}

After that do a loop over the ArrayList and print out the token and its respective occurence from another ArrayList - occurrences.

 

[AgaBoogaBoo]

Originally posted by: George P Burdell

Originally posted by: Xylitol

Originally posted by: George P Burdell

Originally posted by: AgaBoogaBoo
Start by thinking how you would do it yourself if you had to find it, try to mimic that and then improve from there. Write out in words what you would do in simple english, then try to turn this into a flowchart, and finally into the program. It might seem a bit drawn out, but it will help you fully understand how to do it.

Agreed. Draw it out using paper/pencil if that works for you.

BTW, what's your major?

I'm in highschool
I dont even know how to start with the loop to search

Didn't your teacher teach you anything? No textbook?

Oh what the hell, here is clue #1: StringTokenizer

As for loops, just google for or while loops in java and see what you get.

OP: http://java.sun.com/j2se/1.4.2/docs/api/java/util/StringTokenizer.html (1.4.2 version)

Learn to use the docs asap, you'll soon realize that they are an invaluable resource when coding in java.

 

[AgaBoogaBoo]

Originally posted by: George P Burdell

Originally posted by: AgaBoogaBoo
Start by thinking how you would do it yourself if you had to find it, try to mimic that and then improve from there. Write out in words what you would do in simple english, then try to turn this into a flowchart, and finally into the program. It might seem a bit drawn out, but it will help you fully understand how to do it.

Agreed. Draw it out using paper/pencil if that works for you.

BTW, what's your major?

If you were asking me, CompE.

 

[AgaBoogaBoo]

Btw, OP, when is it due? Will you have class before it's due? If so, ask the teacher if you can use StringTokenizer - maybe print out the docs for it and say you found it online when you were looking around on how to solve this.

If not, ask the teacher on your own time outside of class or do something else to figure it out. If you really wanted to avoid using it, you could even view the source code of StringTokenizer and see how they coded it, although that'll be digging very deep. Hmm... ask your teacher if you can and report back. I don't mind helping, but don't have time to sit down and look at this properly right now to see how to do it without stringtokenizer.

 

[Xylitol]

Originally posted by: paulney

Originally posted by: Xylitol

Originally posted by: paulney
Is ArrayList a mandatory class to use? Because it'll perform rather poorly for this task.
So, here's a pseudo-alg of what you do: (I didn't use generics, but you can add them if you want to avoid warnings in 1.5)

Hashtable myWords = new Hashtable();
Scanner scanner = new Scanner(new File("filename"));
while (scanner.hasNext()) {
String newToken = scanner.next();
if (myWord.containsKey(newToken)) {
int occurence = myWords.get(newToken);
occurence++;
myWords.put(newToken, occurence);
}
else {
myWords.put(newToken, 1);
}
}

That's the gist of it.
The default delimiter for scanner is whitespace, so you should be set.

After you exhaust all tokens, print out the contents of the Hashtable using enumeration

Unfortunately, the teacher said that the only classes we can use for that type of stuff are: ArrayLists and Arrays (Since they're the only ones that we have learned so far - Any others and he said we would receive a 50% deduction )

I'm researching hashtables right now on sun java so I can get the gist of what you're doing

Ugh. Ok. That seems odd, but maybe you guys aren't ready for associative collections. Basically, a Hashtable associates a value to a key, so a lookup of any value by its key happens in the same amount of time O(1) whatever the key is. They keys here are your tokens, and the values - number of occurrences in the text.

In order to use ArrayLists, you'll have to run through the list each time you get a token to find if you have already seen it or not. That will slow down your code incredibly (you are now running O(n) operation instead of O(1), where n is the number of tokens you've seen so far, for each new token).

So, the code would look like this:

ArrayList myWords = new ArrayList();
ArrayList occurences = new ArrayList();

Scanner scanner = new Scanner(new File("filename"));
while (scanner.hasNext()) {
String newToken = scanner.next();
boolean tokenFound = false;
int tokenIndex = -1;
int currPos = 0;

while (!tokenFound && currPos < myWords.size()) {
if (myWords[currPos].equals(newToken) {
tokenFound = true;
tokenIndex = currPos;
}
currPos++;
}

if (tokenFound) {
occurences[tokenIndex]++; // check if Integer supports ++ op, I don't remember
}
else {
myWords.add(newToken);
occurences.add(new Integer(0));
}
}

After that do a loop over the ArrayList and print out the token and its respective occurence from another ArrayList - occurrences.

Tried to fix some syntax errors, but my compiler still doesn't like it

You are advised to encapsulate each unique word along with its count in an object that has a toString() method, a compareTo() method and an equals() method as well as appropriate accessor and mutator methods. (Means: you cannot get a passing score without doing this).

My teacher didn't teach ANYTHING about toString () / accessor and mutator methods
I think that I am going to fail this project

 

[Xylitol]

Originally posted by: AgaBoogaBoo
Btw, OP, when is it due? Will you have class before it's due? If so, ask the teacher if you can use StringTokenizer - maybe print out the docs for it and say you found it online when you were looking around on how to solve this.

If not, ask the teacher on your own time outside of class or do something else to figure it out. If you really wanted to avoid using it, you could even view the source code of StringTokenizer and see how they coded it, although that'll be digging very deep. Hmm... ask your teacher if you can and report back. I don't mind helping, but don't have time to sit down and look at this properly right now to see how to do it without stringtokenizer.

It's due tomorrow at 3:30 PM
Apparently, it's supposed to take 1 hour long although no one that I know has been able to do it yet
Unfortunately, we cannot use string tokenizers, etc. because we haven't learned about them (including regular tokens)
We can only use arrays, arraylists, the basics, scanners (hasNext () and next()), toString ()

I'm going to go to sleep right now because I have two exams tomorrow.

I'm very desperate right now with this project because I can't risk dropping from a B+/A- to a C because of one project.
I'll check tomorrow morning for more information that I can use to finish up this project before the end of the school day.

 

[AgaBoogaBoo]

Worst case scenario: Turn in the program with all the proper headers, commenting, etc. that you need to turn in to win at the game called school. Maybe toss some lines down that used stringtokenizer and or a good comment explaining what you looked into.

If you can't solve it, at least try to scavenge all the points possible to keep your grade from dropping as much as possible.

OP - are you able to create a loop to count the number of spaces in the program? If so, don't spaces indicate seperation of words? Start with that, that's at least part of the total amount. You can also create a loop to check for *not* being equal to "- " or " -", count the number of times you encounter them and add them. This should be a simple comparison in which you're moving through it one char at a time.

 

[paulney]

Originally posted by: Xylitol
Tried to fix some syntax errors, but my compiler still doesn't like it

You are advised to encapsulate each unique word along with its count in an object that has a toString() method, a compareTo() method and an equals() method as well as appropriate accessor and mutator methods. (Means: you cannot get a passing score without doing this).

My teacher didn't teach ANYTHING about toString () / accessor and mutator methods
I think that I am going to fail this project

He just wants you to create a separate (public or private - your choice) class (there are no structs in Java). It's easy, but at this point I think no amount of my help is going to help you here.

Anyways, here's a class for you. Stick it in the ArrayList instead of maintaining 2 separate ArrayLists with tokens and occurrences.

public class Entry {
private String token = null;
private int occurrence = 0;

public Entry(String token) {
this.token = token;
occurrence = 1;
}

public String getToken() { return token; };

public int getOccurrence() {return occurrence;};

public void setToken(String token) {this.token = token;};

public void setOccurrence(int occurrence) { this.occurrence = occurrence;};
}

That's it.

 

[paulney]

Originally posted by: AgaBoogaBoo
Btw, OP, when is it due? Will you have class before it's due? If so, ask the teacher if you can use StringTokenizer - maybe print out the docs for it and say you found it online when you were looking around on how to solve this.

If not, ask the teacher on your own time outside of class or do something else to figure it out. If you really wanted to avoid using it, you could even view the source code of StringTokenizer and see how they coded it, although that'll be digging very deep. Hmm... ask your teacher if you can and report back. I don't mind helping, but don't have time to sit down and look at this properly right now to see how to do it without stringtokenizer.

AgaBoogaBoo,

If he's using Scanner, there's no need for Tokenizer. Scanner is a more advanced and powerful concept.

 

[PMChris]

Originally posted by: AgaBoogaBoo

Originally posted by: George P Burdell

Originally posted by: Xylitol

Originally posted by: George P Burdell

Originally posted by: AgaBoogaBoo
Start by thinking how you would do it yourself if you had to find it, try to mimic that and then improve from there. Write out in words what you would do in simple english, then try to turn this into a flowchart, and finally into the program. It might seem a bit drawn out, but it will help you fully understand how to do it.

Agreed. Draw it out using paper/pencil if that works for you.

BTW, what's your major?

I'm in highschool
I dont even know how to start with the loop to search

Didn't your teacher teach you anything? No textbook?

Oh what the hell, here is clue #1: StringTokenizer

As for loops, just google for or while loops in java and see what you get.

OP: http://java.sun.com/j2se/1.4.2/docs/api/java/util/StringTokenizer.html (1.4.2 version)

Learn to use the docs asap, you'll soon realize that they are an invaluable resource when coding in java.

OP stated that he could only use ArrayLists to do this. I'll also be using the capabilities of the String class.

Also, your teacher is pretty ague with the specifications. He has to specify what characters can appear in a word. By your text I am going to assume just alphabetic characters and the hyphen, but this solution would not work if words can contain other characters. In addition I will assume that a single hyphen is not considered a word. He also should specify what output he wants, I've produced output that gives the number of instances of each word in the text and a total word count. An advanced programming course would also specify a bound on the runtime.

This is how I'd do it, going on from your code snippet (you'd pick the code from Option 1 or Option 2, not both):

ArrayList<String> wordList = new ArrayList<String>();
/* Option 1: No visible use of outside class besides String and ArrayList */
String tempWord = null;
while(fin.hasNextLine()) {
String[] words = fin.nextLine().split("[^a-zA-Z-]");
int wordsLength = words.length;
for(int wordIndex = 0; wordIndex < wordsLength; wordIndex++) {
String currentWord = words[wordIndex];
int currentWordLength = currentWord.length();
if(currentWord == null || currentWord.equals("") || currentWord.equals("-")) {
continue;
} else if(wordIndex == (wordsLength - 1) && currentWord.charAt(currentWordLength - 1) == '-') {
// This and the next else if are accounting for the common practice of cutting words with a hyphen at the end of a line for spacing purposes
tempWord = currentWord.substring(0, currentWordLength - 1);
} else if(tempWord != null) {
String newWord = tempWord + currentWord;
wordList.add(newWord);
tempWord = null;
} else {
wordList.add(currentWord);
}
}
}
/* END OPTION 1 */
/* OPTION 2: Less code, does the same thing, uses the Pattern class */
Pattern wordPattern = Pattern.compile("[a-zA-Z-\n]")
while(fin.hasNext(wordPattern)) {
String nextWord = fin.next(wordPattern);
nextWord.replaceAll("-\n", "");
nextWord.replaceAll("\n", "");
if(!nextWord.equals("-"))
wordList.add(nextWord);
}
/* END OPTION 2 */
// How I do this next bit is very lazy and slow, a better solution would be to quicksort the list then walk it with a counter going up until resetting when the String changes, but I don't want to write that
System.out.println("Counts for each word appearing in this text:";
int totalWords = wordList.length();
while(!wordList.isEmpty()) {
String firstWord = wordList.get(0);
int count = 0;
while(wordList.remove(firstWord)) {
count++;
}
System.out.println(firstWord + ": " + count);
}
System.out.println("Total word count: " + totalWords);

That should do it (I didn't compile or test it, so it's probably full of errors, but the idea should come across). My option 1 probably can be written shorter with a slight bump in memory usage, but I should get to bed. You can't submit it because I doubt you know regular expressions.