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Find the most common word from user input

I'm very new to Java creating a software application that allows a user to input text into a field and the program runs through all of the text and identifies what the most common word is. At the moment, my code looks like this:
JButton btnMostFrequentWord = new JButton("Most Frequent Word");
btnMostFrequentWord.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String text = textArea.getText();
String[] words = text.split("\\s+");
HashMap<String, Integer> occurrences = new HashMap<String, Integer>();
for (String word : words) {
int value = 0;
if (occurrences.containsKey(word)) {
value = occurrences.get(word);
}
occurrences.put(word, value + 1);
}
JOptionPane.showMessageDialog(null, "Most Frequent Word: " + occurrences.values());
}
}
This just prints what the values of the words are, but I would like it to tell me what the number one most common word is instead. Any help would be really appreciated.

Just after your for loop, you can sort the map by value then reverse the sorted entries by value and select the first.
for (String word: words) {
int value = 0;
if (occurrences.containsKey(word)) {
value = occurrences.get(word);
}
occurrences.put(word, value + 1);
}
Map.Entry<String,Integer> tempResult = occurrences.entrySet().stream()
.sorted(Map.Entry.<String, Integer>comparingByValue().reversed())
.findFirst().get();
JOptionPane.showMessageDialog(null, "Most Frequent Word: " + tempResult.getKey());

For anyone who is more familiar with Java, here is a very easy way to do it with Java 8:
List<String> words = Arrays.asList(text.split("\\s+"));
Collections.sort(words, Comparator.comparingInt(word -> {
return Collections.frequency(words, word);
}).reversed());
The most common word is stored in words.get(0) after sorting.

I would do something like this
int max = 0;
String a = null;
for (String word : words) {
int value = 0;
if(occurrences.containsKey(word)){
value = occurrences.get(word);
}
occurrences.put(word, value + 1);
if(max < value+1){
max = value+1;
a = word;
}
}
System.out.println(a);
You could sort it, and the solution would be much shorter, but I think this runs faster.

You can either iterate through occurrences map and find the max or
Try like below
String text = textArea.getText();;
String[] words = text.split("\\s+");
HashMap<String, Integer> occurrences = new HashMap<>();
int mostFreq = -1;
String mostFreqWord = null;
for (String word : words) {
int value = 0;
if (occurrences.containsKey(word)) {
value = occurrences.get(word);
}
value = value + 1;
occurrences.put(word, value);
if (value > mostFreq) {
mostFreq = value;
mostFreqWord = word;
}
}
JOptionPane.showMessageDialog(null, "Most Frequent Word: " + mostFreqWord);

Assign strings from a string array to various string variables

what I want to do:
I want to extract every string from a string array to a different string variable.
Outputting this to the console is no problem of course, just iterate over the array.
But when it comes to assigning each value to a different variable, I dont get any further right now. All I found online were suggestions on how to concatenate each index of the array. That is not what I want. I had a similar solution for ints some time ago, but I cannot come up with it right now.
int answerPackagerCounter = 0;
String answerPackager = "answer" + answerPackagerCounter;
String answer0 = "";
String answer1 = "";
String answer2 = "";
String answer3 = "";
boolean correct0 = false;
boolean correct1 = false;
boolean correct2 = false;
boolean correct3 = false;
for(int k = 0; k < answers.size(); k++ ){
answerPackager = answers.get(k);
}
Of course this does not work, since each time answerPackager is overwritten. I'm quite sure not much is missing here, but I can't see it right now.
Any input is appreciated, thanks in advance!

What I've read is that a Map is probably the best way to go. Where the key can be treated as your separate variable and the value of each key is the value.
You probably would want to create an string array of answer & correct variables that will hole answer0, answer1, etc... & correct0, correct1, etc... That way you can avoid hardcoding
public static void main(String[] args) throws Exception {
String[] answers = new String[] { "Blah1", "Blah2", "Blah3", "Blah4" };
String[] correct = new String[] { "false", "true", "false", "false" };
Map<String, String> answersCorrect = new HashMap();
for (int i = 0; i < answers.length; i++) {
answersCorrect.put("answer" + i, answers[i]);
}
for (int i = 0; i < correct.length; i++) {
answersCorrect.put("correct" + i, correct[i]);
}
// Keys are not stored in order of setting
for (String key : answersCorrect.keySet()) {
System.out.println("Key: " + key + " Value: " + answersCorrect.get(key));
}
System.out.println("");
// Direct usage
System.out.println(answersCorrect.get("answer0") + " " + answersCorrect.get("correct0"));
}
Results:

How about making two arrays, String[] answer = new String[4]; Boolean[] correct= new Boolean[4];
Better, create a class like this:
public Class Answers {
private String[] answer = new String[4];
private Boolean[] correct= new Boolean[4];
... Usuals getters and setters...
}

Add to list at certain index

I'm having a problem with some list manipulation. I take the user's input and search through it: if i find an "=" sign i assume that the string in front of it is the name of a variable , so on the line right above that variable i want to add a new string to the user's input (in this case it is called "tempVAR", doesn't really matter though). I've been trying to do this with StringBuilder but without any success , so i currently am trying to do it with ArrayLists but I am getting stuck at adding new elements to the list. Because of the way list.add(index,string) works , the elements to the right of what i am adding will always add +1 to their index. Is there a way to always know exactly what index i am looking for even after a random number of string has been added? Here is my code so far, if you run it you will see what i mean, instead of "tempVAR" or "tempVar1" being added above the name of the variable they will be added one or to positions in the wrong way.
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map.Entry;
public class ToTestStuff {
static List<String> referenceList = new ArrayList<String>();
public static final String SEMICOLUMN = ";";
public static final String BLANK = " ";
public static final String EMPTY = "";
public static final String LEFT_CURLY = "{";
public static final char CARRIAGE_RETURN = '\r';
public static final String CR_STRING = "CARRIAGE_RETURN_AND_NEW_LINE";
public static final char NEW_LINE = '\n';
public static void main(String[] args) {
List<String> test = new ArrayList<String>();
String x = "AGE_X";
String y = "AGE_Y";
String z = "AGE_YEARS";
String t = "P_PERIOD";
String w = "T_VALID";
referenceList.add(x);
referenceList.add(y);
referenceList.add(z);
referenceList.add(t);
referenceList.add(w);
String text2 = " if ( AGE_YEARS > 35 ) {\r\n"
+ " varX = P_PERIOD ;\r\n"
+ " }\r\n"
+ " if ( AGE_YEARS < 35 ) {\r\n"
+ " varY = T_VALID ;\r\n"
+ " varZ = AGE_Y ;\r\n"
+ " varA = AGE_X ;\r\n"
+ " }";
detectEquals(text2);
}
public static String detectEquals(String text) {
String a = null;
// text = text.trim();
// text = TestSplitting.addDelimiters(text);
String[] newString = text.split(" ");
List<String> test = Arrays.asList(newString);
StringBuilder strBuilder = new StringBuilder();
HashMap<String, List<Integer>> signs = new HashMap<String, List<Integer>>();
HashMap<String, List<Integer>> references = new HashMap<String, List<Integer>>();
HashMap<Integer, Integer> indexesOfStringAndList = new HashMap<Integer, Integer>();
List<String> testList = new ArrayList<String>();
List<Integer> lastList = new ArrayList<Integer>();
List<Integer> indexList = new ArrayList<Integer>();
List<Integer> refList = new ArrayList<Integer>();
List<String> keysList = new ArrayList<String>();
List<List> minList = new ArrayList<List>();
String previous = null;
int index = 0;
Object obj = new Object();
List<Integer> referenceValueList = new ArrayList<Integer>();
List<Integer> indexPosition = new ArrayList<Integer>();
String b = null;
int indexOfa = 0;
// System.out.println("a----> " + test);
List<String> anotherList = new ArrayList(test);
for (int i = 0; i < anotherList.size(); i++) {
a = anotherList.get(i).trim();
index = strBuilder.length();// - a.length();
// index = i;
strBuilder.append(a); // "=", 3 - if, 14 - while, 36 , "=", 15
testList.add(a);
if (a.equals("if") || a.equals("=")) {
lastList.add(i);
indexOfa = i;
indexesOfStringAndList.put(index, indexOfa);
refList.add(index);
indexPosition.add(index);
if (signs.containsKey(a)) {
signs.get(a).add(index);
} else {
signs.put(a, refList);
}
refList = new ArrayList<Integer>();
}
if (referenceList.contains(a)) {
indexList.add(index);
if (references.containsKey(a)) {
references.get(a).add(index);
} else {
references.put(a, indexList);
}
indexList = new ArrayList<Integer>();
}
}
for (String k : references.keySet()) {
keysList.add(k);
referenceValueList = references.get(k);
obj = Collections.min(referenceValueList);
int is = (Integer) obj;
ArrayList xx = new ArrayList();
xx.add(new Integer(is));
xx.add(k);
minList.add(xx);
}
for (List q : minList) {
Integer v = (Integer) q.get(0);
String ref = (String) q.get(1);
int x = closest(v, indexPosition);
int lSize = anotherList.size();
int sizeVar = lSize - test.size();
int indexOfPx = 0;
int px = 0;
if (x != 0) {
px = indexesOfStringAndList.get(x) - 1;
} else {
px = indexesOfStringAndList.get(x);
}
if (px == 0) {
System.out.println("previous when x=0 " +anotherList.get(px+sizeVar));
anotherList.add(px, "tempVar1=\r\n");
} else {
previous = anotherList.get(px + sizeVar);
System.out.println("previous is---> " + previous + " at position " + anotherList.indexOf(previous));
anotherList.add(anotherList.indexOf(previous) - 1, "\r\ntempVAR=");
}
}
strBuilder.setLength(0);
for (int j = 0; j < anotherList.size(); j++) {
b = anotherList.get(j);
strBuilder.append(b);
}
String stream = strBuilder.toString();
// stream = stream.replaceAll(CR_STRING, CARRIAGE_RETURN + EMPTY + NEW_LINE);
System.out.println("after ----> " + stream);
return stream;
}
public static int closest(int of, List<Integer> in) {
int min = Integer.MAX_VALUE;
int closest = of;
for (int v : in) {
final int diff = Math.abs(v - of);
if (diff < min) {
min = diff;
closest = v;
}
}
return closest;
}
}
I've mapped the positions of the "=" and "if" to their positions in the StringBuilder, but these are remnants from when i was trying to use a stringBuilder to do what i said above.
I have been struggling with this for a few days now and still haven't managed to do what i need, i am not sure where i am going wrong. At the moment i am hellbent on making this work as it is (with either lists or string builder) after which , if there is a better way i will look into that and adapt this accordingly.
The addDelimiters() method is a method i created to avoid writing the string as you see it in "String text2" but i took that out for this because it would only clutter my already chaotic code even more :), i don't think it has any relevance to why what i am trying to do is not working.
TLDR: at the line above front of every varX or varY or other "var" i would like to be able to add a string to the list but i think my logic in getting the variable names or in adding to the list is wrong.

I think we both know that your code is messed up and that you need many more abstractions to make it better. But you could make it work by maintaining an offset variable, lets say "int offset". Each time you insert a string after the initial pass you increment it, and when you access the list you use it, "list.get(index+offset);". Read up on Abstract syntax trees. , which are a great way to parse and manipulate languages.

Manipulating a user's input

So I'm trying to manipulate the user's input in such a way that when I find a certain string in his input I turn that into a variable and replace the string with the name of the variable. (jumbled explanation I know, maybe an example will make it more clear).
public class Test {
static List<String> refMap = new ArrayList<String>();
public static void main(String[] args) {
String x = "PROPERTY_X";
String y = "PROPERTY_Y";
refMap.add(x);
refMap.add(y);
String z = "getInteger("PROPERTY_X)";
String text = "q=PROPERTY_X+10/(200*PROPERTY_X)";
String text1 = "if(PROPERTY_X==10){"
+ "j=1;"
+ "PROPERTY_X=5; "
+ "if(true){"
+ "m=4/PROPERTY_X"
+ "}"
+ "}";
detectEquals(text);
}
public static String detectEquals(String text) {
String a = null;
text = TestSplitting.addDelimiters(text);
String[] newString = text.split(" ");
List<String> test = Arrays.asList(newString);
StringBuilder strBuilder = new StringBuilder();
HashMap<String, Integer> signs = new HashMap<String, Integer>();
HashMap<String, Integer> references = new HashMap<String, Integer>();
List<String> referencesList = new ArrayList<String>();
List<Integer> indexList = new ArrayList<Integer>();
int index = 0;
for (int i = 0; i < test.size(); i++) {
a = test.get(i).trim();
//System.out.println("a= " + a);
strBuilder.append(a);
index = strBuilder.length() - a.length();
if (a.equals("=")) {
signs.put(a, index);
indexList.add(index);
// System.out.println("signs map--> : "+signs.get(a));
}
if (refMap .contains(a)) {
references.put(a, index);
// System.out.println("reference index-> "+references.get(a));
// System.out.println("reference-> "+references.toString());
}
}
//stuck here
for (String s : references.keySet()) {
//System.out.println("references-> " + s);
int position = references.get(s);
for (int j : indexList) {
if (j <= position) {
System.out.println(j);
}
}
//strBuilder.insert(j - 1, "temp1=\r\n");
}
System.out.println(strBuilder);
return a;
}
Say the user inputs the content of the string "text", I'm trying to parse that input so when I find "PROPERTY_X", I want to create a variable out of it and place it right before the occurrence of text, and then replace "PROPERTY_X" with the name of the newly created variable.
The reason I'm also searching for "=" sign is because I only want to do the above for the first occurrence of "PROPERTY_X" in the whole input and then just replace "PROPERTY_X" with tempVar1 wherever else I find "PROPERTY_X".
ex:
tempVar1=PROPERTY_X;
q=tempVar1+10/(200*tempVar1);
Things get more complex as the user input gets more complex, but for the moment I'm only trying to do it right for the first input example I created and then take it from there :).
As you can see, I'm a bit stuck on the logic part, the way I went with it was this:
I find all the "=" signs in the string (when I move on to more complex inputs I will need to search for conditions like if,for,else,while also) and save each of them and their index to a map, then I do the same for the occurrences of "PROPERTY_X" and their indexes. Then I try to find the index of "=" which is closest to the index of the "PROPERTY_X" and and insert my new variable there, after which I go on to replace what I need with the name of the variable.
Oh the addDelimiters() method does a split based on some certain delimiters, basically the "text" string once inserted in the list will look something like this:
q
=
PROPERTY_X
+
10
etc..
Any suggestions are welcome.

Java:how to group similar strings (items) to respective array (group)?

I have the following string "0#Aitem, 0#Aitem2, 0#Aitem3, 1#Bitem, 1#Bitem2, 2#Citem, Nitem, Nitem2".
the 0# shows group number. so Aitem, Aitem2, Aitem3 will belong to group 0. Bitem, Bitem2 in group 1. Citem in group 2. If there is no group number, they will all be place in separate group. So Nitem, Nitem2 will be placed in group 3.
I would like to create an array for each group, and place the "items" in respective group(array). So I would end up with something like
[array("Aitem,Aitem2,Aitem3"), array("Bitem, Bitem2"), array("Citem"), array("Nitem, Nitem2")]
I am guessing I need an arrayList to hold all the groups (arrays) which respectively has appropriate elements (items).
This is what I started with but I don't know if this is the best approach. The string is dynamic, so there can be any number of groups and has to follow the criteria above.
String[] x = Pattern.compile(",").split("0#item, 0#item2, 0#item3, 1#item, 1#item2, 2#item, item");
for (int ii=0; ii<x.length; ii++) {
System.out.println(i + " \"" + x[ii] + "\"");
}

My answer shows how you can use a single regex to extract both the group and the item. You can then store these in a map.
String s = "0#Aitem, 0#Aitem2, 0#Aitem3, 1#Bitem, 1#Bitem2, 2#Citem, Nitem, Nitem2";
Pattern p = Pattern.compile("(\\d*)[#]{0,1}(\\w+?)(,|$)");
Matcher m = p.matcher(s);
Map<String, List<String>> map = new TreeMap<String, List<String>>();
while(m.find()){
String group = m.group(1);
String item = m.group(2);
List<String> items = map.get(group);
if(items == null){
items = new ArrayList<String>();
map.put(group, items);
}
items.add(item);
}
//let's print it out
for(String key : map.keySet()){
System.out.println(key + " : " + map.get(key));
}
prints:
: [Nitem, Nitem2]
0 : [Aitem, Aitem2, Aitem3]
1 : [Bitem, Bitem2]
2 : [Citem]
At the moment, items with no group are keyed against an empty string. I'll leave it at as an exercise for you to handle this scenario. It should simply be a case of finding the max key and incrementing it.
I'm sure the regex can be improved too as it was written in haste.

//Create a map for storing groups
Map<String, Collection<String>> groupMap = new HashMap<String, Collection<String>>();
String[] parts = yourString.split("[, ]+"); //Split by each word
for (String part : parts) { //Go over all words
String[] subparts = part.split("#"); //Split to index and value
String groupKey;
String value;
if (subparts.length == 1) { //There is no '#' sign
groupKey = null;
value = subparts[0];
} else if (subparts.length == 2) { //There is one '#'sign
groupKey = subparts[0];
value = subparts[1];
} else {
throw new IllegalArgumentException("Can not parse string");
}
Collection<String> groupContents = groupMap.get(groupKey); //Extract list of items in this group
if (groupContents == null) { //If there was no such group yet - create one
groupMap.put(groupKey, groupContents = new ArrayList<String>());
}
groupContents.add(value); //Add item to group
}

HashMap<String,List<String> myItems = new HashMap<String,List<String>);
Then you can whatever class you want with an sting alias and store as many items as you whish.

You are on right way but I'd like to correct you a little bit.
Use the following regex to split: str.split("\\s*,\\s*"). This will support all possible spaces.
When you get separate item you have to split it again: item.split("#").
To store all this create data structure like List<List<String>>. Then do the following:
String[] parts = item.split("#");
int group = Integer.parseInt(parts[0]);
String itemName = parts[1];
List<String> groupList = allGroups.get(group);
if (groupList == null) {
groupList = new ArrayList<String>();
allGroups[group] = groupList;
}
groupList.add(itemName);
I am sorry if the code sample contains syntax errors. It is written here, on the site and should just help you to see the idea.

Another solution based on Maps.
System.out.println("###Parsing results and populating map");
String[] x = Pattern.compile("\\s*,\\s*").split(
"0#item, 0#item2, 0#item3, 1#item, 1#item2, 2#item, item");
Map<String, List<String>> result = new TreeMap<String, List<String>>();
for (int i = 0; i < x.length; i++) {
String y[] = x[i].split("#");
if (y.length > 1) {
System.out.println("group: '" + y[0] + "' item: '" + y[1] + "'");
List<String> l = result.get(y[0]);
if(l==null){
l = new ArrayList<String>();
result.put(y[0], l);
}
l.add(y[1]);
}
}
System.out.println("###Returning values stored in map, as separate arrays");
for(Entry<String,List<String>> entry: result.entrySet()){
System.out.println("Group:" + entry.getKey());
//System.out.println("Items:");
List <String> l = entry.getValue();
// This is where the final array is
String[] finalArray = l.toArray(new String[1]);
for (int i = 0; i < finalArray.length; i++) {
System.out.println(finalArray[i]);
}
}