Code so far:
public class test1 {
public static void main(String[] args) throws IOException {
//declare reader and writer
BufferedReader reader = null;
PrintWriter writer = null;
//hash maps to store the data
HashMap<String, String> names = new HashMap<String, String>();
//read the first file and store the data
reader = new BufferedReader(new InputStreamReader(new FileInputStream(new File("IRStudents.txt"))));
String line;
String[] arg;
while ((line = reader.readLine()) != null) {
if (!line.startsWith("-")) {
arg = line.split(" ");
names.put(arg[0], arg[1]);
}
}
reader.close();
//read the second file, merge the data and output the data to the out file
writer = new PrintWriter(new FileOutputStream(new File("File_2.txt")));
reader = new BufferedReader(new InputStreamReader(new FileInputStream(new File("Marks.txt"))));
while((line = reader.readLine()) != null){
arg = line.split(" ");
writer.println(arg[0] + " " + names.get(arg[0]));
writer.println("Marks: " + arg[1]);
writer.println("- - - - - -");
}
writer.flush();
writer.close();
reader.close();
}
}
So the output in the text file looks like:
25220 Fiona
Marks: 68.3
- - - - - -
25212 Greg
Marks: 70.5
- - - - - -
I have ANOTHER text file with another set of marks with the same layout as the first mark file.
Now I want to add a new set of marks to the set of data So it should look like this:
25220 Fiona
Marks: 68.3 Marks2: 21.2
- - - - - -
25212 Greg
Marks: 70.5 Marks2: 23.43
- - - - - -
So what can I do to add? I assume I have to add a new Hashmap for the new text document? But when I tried doing all of that it never fully works.
IR Student:
25987 Alan
25954 Betty
25654 Chris
25622 David
You could do the following too.
package toBeDeleted;
import java.util.HashMap;
import java.util.Map;
import java.util.Objects;
public class MarksProcessor {
private final Map<String, Record> map = new HashMap<>();
public static void main(String[] args) {
String fileName = "file1.txt"; // change it to your specific file.
MarksProcessor marksProcessor = new MarksProcessor();
marksProcessor.processFile(fileName, 0);
fileName = "file2.txt";
marksProcessor.processFile(fileName, 1);
marksProcessor.writeData();
}
private void processFile(String fileName, int marksIndex) {
try(/*specify your reader resources here*/) {
// read the first record and get rollNumber, name and marks.
String roll = "valueYouGot";
double value = 0.0; // the value you read.
Record record = map.get(roll);
// if record is null, you need to create one
// and put it into the map.
//record.updateMarks(marksndex, value);
}
}
private void writeData() {
// if this needs to be written to a file/stream, create a writer.
for (Map.Entry<String, Record> entry : map.entrySet()) {
String roll = entry.getKey();
Record record = entry.getValue();
if (record != null) {
String name = record.getName();
double marks1 = record.getMarks(0);
double marks2 = record.getMarks(1);
// Now you have all the values. Print them
// however you like. Wherever you like.
}
}
}
static class Record {
private String name;
private double[] marks = new double[2];
Record(String name) {
this.name = name;
}
public String getName() {
return name;
}
public double getMarks(int index) {
if (index < 0 || index > 1)
throw new IllegalArgumentException("index should be 0 or 1 but"
+ " the supplied index was " + index);
return marks[index];
}
public void updateMarks(int index, double value ) {
if (index < 0 || index > 1)
throw new IllegalArgumentException("index should be 0 or 1 but"
+ " the supplied index was " + index);
marks[index] = value;
}
#Override
public String toString() {
return "the way you want to type your output";
}
}
}
I think you are doing too much String manipulation. And if you will have more marks' files to process in a similar way, the String manipulation is likely going to increase which could make your code less readable and could give more room for errors. I think following would be a better approach.
You could create a MarksRecord class with the following structure.
public class MarksRecord {
private String subject; // or whatever this variable name should be.
// in your case it should hold value marks1.
private double marks;
}
Similarly you could create an immutable Student/similar class as follows. This could be a value class with equals and hashCode methods based on the first number you are reading in each file. I am guessing it is roll number or similar that can identify a student in a unique way.
public final class Student {
private final String rollNumber;
private final String name;
// equals, hashCode, and other methods.
}
Then in your main method you could have a
Map<Student, ArrayList<MarksRecord>>
. Alternatively you could also use a
Map<String, ArrayList<MarksRecord>>
where the first String is the roll number of a Student record.
This way every time you have a new file of marks, your data structure will be able to accomodate it.
When adding the new marks, use this to add them to the already existing ones:
String key = arg[0];
String secondMarks = arg[1];
String theMarks = names.get(key);
theMarks = theMarks + " Marks2: " + secondMarks;
names.put(key, theMarks);
I think I understand your problem, let me know if this is incorrect.
The requirement is to have all marks that the person receved on its own line...
Theres two print functions in the System.out stream.
print and println
arg = line.split(" ");
writer.println(arg[0] + " " + names.get(arg[0]));
writer.print("Marks: " + arg[1]);
for(int i = 2; i < args.length; i++){
writer.println(" Marks" + i + ": " + arg[i]);
}
writer.println("\n- - - - - -");
Related
I would like to count countX and countX using the same loop instead of creating three different loops. Is there any easy way approaching that?
public class Absence {
private static File file = new File("/Users/naplo.txt");
private static File file_out = new File("/Users/naplo_out.txt");
private static BufferedReader br = null;
private static BufferedWriter bw = null;
public static void main(String[] args) throws IOException {
int countSign = 0;
int countX = 0;
int countI = 0;
String sign = "#";
String absenceX = "X";
String absenceI = "I";
try {
br = new BufferedReader(new FileReader(file));
bw = new BufferedWriter(new FileWriter(file_out));
String st;
while ((st = br.readLine()) != null) {
for (String element : st.split(" ")) {
if (element.matches(sign)) {
countSign++;
continue;
}
if (element.matches(absenceX)) {
countX++;
continue;
}
if (element.matches(absenceI)) {
countI++;
}
}
}
System.out.println("2. exerc.: There are " + countSign + " rows int the file with that sign.");
System.out.println("3. exerc.: There are " + countX + " with sick note, and " + countI + " without sick note!");
} catch (FileNotFoundException ex) {
Logger.getLogger(Absence.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
text file example:
# 03 26
Jujuba Ibolya IXXXXXX
Maracuja Kolos XXXXXXX
I think you meant using less than 3 if statements. You can actually so it with no ifs.
In your for loop write this:
Countsign += (element.matches(sign)) ? 1 : 0;
CountX += (element.matches(absenceX)) ? 1 : 0;
CountI += (element.matches(absenceI)) ? 1 : 0;
Both answers check if the word (element) matches all regular expressions while this can (and should, if you ask me) be avoided since a word can match only one regex. I am referring to the continue part your original code has, which is good since you do not have to do any further checks.
So, I am leaving here one way to do it with Java 8 Streams in "one liner".
But let's assume the following regular expressions:
String absenceX = "X*";
String absenceI = "I.*";
and one more (for the sake of the example):
String onlyNumbers = "[0-9]*";
In order to have some matches on them.
The text is as you gave it.
public class Test {
public static void main(String[] args) throws IOException {
File desktop = new File(System.getProperty("user.home"), "Desktop");
File txtFile = new File(desktop, "test.txt");
String sign = "#";
String absenceX = "X*";
String absenceI = "I.*";
String onlyNumbers = "[0-9]*";
List<String> regexes = Arrays.asList(sign, absenceX, absenceI, onlyNumbers);
List<String> lines = Files.readAllLines(txtFile.toPath());
//#formatter:off
Map<String, Long> result = lines.stream()
.flatMap(line-> Stream.of(line.split(" "))) //map these lines to words
.map(word -> regexes.stream().filter(word::matches).findFirst()) //find the first regex this word matches
.filter(Optional::isPresent) //If it matches no regex, it will be ignored
.collect(Collectors.groupingBy(Optional::get, Collectors.counting())); //collect
System.out.println(result);
}
}
The result:
{X*=1, #=1, I.=2, [0-9]=2}
X*=1 came from word: XXXXXXX
#=1 came from word: #
I.*=2 came from words: IXXXXXX and Ibolya
[0-9]*=2 came from words: 03 and 06
Ignore the fact I load all lines in memory.
So I made it with the following lines to work. It escaped my attention that every character need to be separated from each other. Your ternary operation suggestion also nice so I will use it.
String myString;
while ((myString = br.readLine()) != null) {
String newString = myString.replaceAll("", " ").trim();
for (String element : newString.split(" ")) {
countSign += (element.matches(sign)) ? 1 : 0;
countX += (element.matches(absenceX)) ? 1 : 0;
countI += (element.matches(absenceI)) ? 1 : 0;
So I have to read out a string from a file in Java. It's for a highscore system.
Each line of the file contains something similiar like this: "24/Kilian".
The number in front of the / is the score and the text after the / is the name.
Now, my problem is that I have to sort the scores descending and write them back into the file. The new scores should overwrite the old ones.
I tried it but I can't get it working properly.
I already wrote some code which reads the score + name line by line out of the file.
public static void sortScores() {
String [][]scores = null;
int i = 1;
try (BufferedReader br = new BufferedReader(new FileReader("score.txt"))) {
String line;
while ((line = br.readLine()) != null) {
System.out.println(line);
scores[i][0] = line.substring(0, line.indexOf("/"));
scores[i][1] = line.substring(line.indexOf("/"), line.length());
i++;
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
So, this code basically writes the score and the name in a 2D array like this:
score[0][0] = "24";
score[0][1] = "Kilian";
score[1][0] = "33";
score[1][1] = "Name";
score[2][0] = "45";
score[2][1] = "AnotherName";
I hope someone can help me with my problem.
You can use java.util.Arrays's sort-Method:
Arrays.sort(scores, (a, b) -> -a[0].compareTo(b[0]));
But this lead to the case that "3" will be above "23". So probably you should create new class which holds the value and use an ArrayList
I'd recomend you to make a new class Score which holds your data (score + name) and add a new instance of Score into a ArrayList for each row you read from the file. After that you can implement a Comparator and sort your ArrayList. It's much easier because you don't know how big your string array will get and you need to know that when you're working with arrays.
public class Score {
public Score(int score, String name) {
this.score = score;
this.name = name;
}
int score;
String name;
// getter
}
List<Score> scoreList = new ArrayList<>();
String line;
while ((line = br.readLine()) != null) {
scoreList.add(new Score(Integer.parseInt(line.substring(0, line.indexOf("/"))), line.substring(line.indexOf("/"), line.length())));
}
Collections.sort(scoreList, new Comparator<Score>() {
public int compare(Score s1, Score s2) {
return s1.getScore() - s2.getScore();
}
}
// write to file
You can try it:
HashMap<Integer, String > map = new HashMap<>();
try (BufferedReader br = new BufferedReader(new FileReader("score.txt"))) {
String line;
while ((line = br.readLine()) != null) {
System.out.println(line);
String[] lines = line.split("/");
map.put(Integer.valueOf(lines[0]),lines[1]);
}
SortedSet<Integer> keys = new TreeSet<Integer>(map.keySet());
keys.forEach(k -> System.out.println(map.get(k).toString() + " value " + k ));
Use Arrays.sort(arr, comparator) with a custom comparator:
Arrays.sort(theArray, new Comparator<String[]>(){
#Override
public int compare(final String[] first, final String[] second){
// here you should usually check that first and second
// a) are not null and b) have at least two items
// updated after comments: comparing Double, not Strings
// makes more sense, thanks Bart Kiers
return Double.valueOf(second[1]).compareTo(
Double.valueOf(first[1])
);
}
});
System.out.println(Arrays.deepToString(theArray));
Good day!
I have created a code using Netbeans and it executes the processes just fine.
Now, i want my input to given and output to be displayed through a user interface. I have then created a 2 Jframes, 1 to collect the user's input and the other to display the results after execution by the code.
But, i am unable to link the interface to the main class(called NgramBetaE) as i am not aware of how i can do so.
I highly welcome suggestions.
The main class in its entirety is;
package ngrambetae;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;
import java.util.*;
/**
*
* #author 201102144
*/
public class NgramBetaE {
static LinkedList<String> allWords = new LinkedList<String>();
static LinkedList<String> distinctWords = new LinkedList<String>();
static String[] hashmapWord = null;
static int wordCount;
public static HashMap<String,HashMap<String, Integer>> hashmap = new HashMap<>();
public static HashMap<String,HashMap<String, Integer>> bigramMap = new HashMap<>();
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
//prompt user input
Scanner input = new Scanner(System.in);
//read words from collected corpus; a number of .txt files
File directory = new File("Corpus");
File[] listOfFiles = directory.listFiles();//To read from all listed iles in the "directory"
int lineNumber = 0;
String line;
String files;
String delimiters = "[()?!:;,.\\s]+";
//reading from a list of text files
for (File file : listOfFiles) {
if (file.isFile()) {
files = file.getName();
try {
if (files.endsWith(".txt") || files.endsWith(".TXT")) { //ensures a file being read is a text file
BufferedReader br = new BufferedReader(new FileReader(file));
while ((line = br.readLine()) != null) {
line = line.toLowerCase();
hashmapWord = line.split(delimiters);
//CALCULATING UNIGRAMS
for(int s = 0; s < hashmapWord.length; s++){
String read = hashmapWord[s];
allWords.add(read);
//count the total number of words in all the text files combined
//TEST
wordCount = 0;
for (int i = 0; i < allWords.size(); i++){
wordCount ++;
}
}
//CALCULATING BIGRAM FREQUENCIES
for(int s = 0; s < hashmapWord.length -1; s++){
String read = hashmapWord[s];
final String read1 = hashmapWord[s + 1];
HashMap<String, Integer> counter = bigramMap.get(read);
if (null == counter) {
counter = new HashMap<String, Integer>();
bigramMap.put(read, counter);
}
Integer count = counter.get(read1);
counter.put(read1, count == null ? 1 : count + 1);
}
//CALCULATING TRIGRAM FREQUENCIES
for(int s = 0; s < hashmapWord.length - 2; s++){
String read = hashmapWord[s];
String read1 = hashmapWord[s + 1];
final String read2 = hashmapWord[s + 2];
String readTrigrams = read + " " + read1;
HashMap<String, Integer> counter = hashmap.get(readTrigrams);
if (null == counter) {
counter = new HashMap<String, Integer>();
hashmap.put(readTrigrams, counter);
}
Integer count = counter.get(read2);
counter.put(read2, count == null ? 1 : count + 1);
}
}
br.close();
}
} catch (NullPointerException | IOException e) {
e.printStackTrace();
System.out.println("Unable to read files: " + e);
}
}
}
//COMPUTING THE TOTAL NUMBER OF WORDS FROM ALL THE TEXT FILES COMBINED
System.out.println("THE TOTAL NUMBER OF WORDS IN COLLECTED CORPUS IS : \t" + wordCount + "\n");
for(int i = 0, size = allWords.size(); i < size; i++){
String distinctWord = allWords.get(i);
//adding a word into the 'distinctWords' list if it doesn't already occur
if(!distinctWords.contains(distinctWord)){
distinctWords.add(distinctWord);
}
}
//PRINTING THE DISTINCT WORDS
System.out.println("THE DISTINCT WORDS IN TOTAL ARE :\t " + distinctWords.size() + "\n");
System.out.println("PRINTING CONTENTS OF THE BIGRAMS HASHMAP... ");
System.out.println(bigramMap);
System.out.println("================================================================================================================================================================================================================================================================================================================\n");
System.out.println("PRINTING CONTENTS OF THE TRIGRAMS HASHMAP... ");
System.out.println(hashmap);
System.out.println("================================================================================================================================================================================================================================================================================================================\n");
//QUITTING APPLICATION
String userInput = null;
while(true) {
System.out.println("\n**********************************************************************************************************************************************************************************************************************************");
System.out.println("\n\n\t\tPLEASE ENTER A WORD OR PHRASE YOU WOULD LIKE A PREDICTION OF THE NEXT WORD FROM:");
System.out.println("\t\t\t\t(OR TYPE IN 'Q' OR 'q' TO QUIT)");
userInput = input.nextLine();
if (userInput.equalsIgnoreCase("Q")) break;
//FORMAT USER INPUT
String[] users = userInput.toLowerCase().split("[?!,.\\s]+");
if (users.length < 2) {
userInput = users[0];
//System.out.println("\nENTRY '" + userInput + "' IS TOO SHORT TO PREDICT NEXT WORD. PLEASE ENTER 2 OR MORE WORDS");
//CALCULATING BIGRAM PROBABILITY
int sum = 0;
try {
for(String s : bigramMap.get(userInput).keySet()) {
sum += bigramMap.get(userInput).get(s);
}
String stringHolder = null;
double numHolder = 0.0;
for(String s : bigramMap.get(userInput).keySet()) {
//System.out.println("TWO");
double x = Math.round(bigramMap.get(userInput).put(s, bigramMap.get(userInput).get(s))/ (double)sum *100 );
if(s != null){
if(numHolder < x ){
stringHolder = s;
numHolder = x;
}
}
}
System.out.println("\nNEXT WORD PREDICTED IS '" + stringHolder + "'");
System.out.println("ITS PROBABILITY OF OCCURRENCE IS " + numHolder + "%");
} catch (Exception NullPointerException) {
System.out.println("\nSORRY. MATCH NOT FOUND.");
}
} else {
userInput = users[users.length - 2] + " " + users[users.length - 1];
// System.out.println("FROM USER WE GET....");
// System.out.println(bigrams.get(userInput).keySet());
/* CALCULATING TRIGRAM PROBABILITY*/
int sum = 0;
try {
for(String s : hashmap.get(userInput).keySet()) {
sum += hashmap.get(userInput).get(s);
}
String stringHolder = null;
double numHolder = 0.0;
for(String s : hashmap.get(userInput).keySet()) {
//System.out.println("TWO");
double x = Math.round(hashmap.get(userInput).put(s, hashmap.get(userInput).get(s))/ (double)sum *100 );
if(s != null){
if(numHolder < x ){
stringHolder = s;
numHolder = x;
}
}
}
System.out.println("\nNEXT WORD PREDICTED IS '" + stringHolder + "'");
System.out.println("ITS PROBABILITY OF OCCURRENCE IS " + numHolder + "%");
} catch (Exception NullPointerException) {
System.out.println("\nSORRY. MATCH NOT FOUND.");
}
}
}
input.close();
}
}
My first Jframe which i would like to appear upon running the project has got a single textbox and a single button;
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
String usersInput = jTextField1.getText();
Interface1 s = new Interface1();
s.setVisible(true);
dispose();
}
i would like for the user to enter data in the textbox and when they click on the button 'predict next word' then the output from the code execution is displayed on the second jframe which has got 3 labels and relative text areas.
NOTE; i couldn't paste the screenshots but if you run the NgramBetaE class you will get an idea of how the interfaces will be as i tried to explain them.
Thank you
Don't even try to link your GUI code to your NgramBetaE code as you've more work to do since the NgramBetaE is little more than one huge static main method that gets user input from the console with a Scanner and outputs to the console via printlns. Melding these two is like trying to put a square peg into a round hole.
Instead re-write the whole thing with an eye towards object-oriented coding, including creation of an OOP-compliant model class with instance fields and methods, and a single GUI that gets the input and displays it, that holds an instance of the model class and that calls instance methods on this instance.
Consider creating non-GUI classes and methods for --
Reading in data from your text files
Analyzing and hashing the data held in the text files including calculating word frequencies etc...
Returning needed data after analysis in whatever data form it may be needed.
A method for allowing input of a String/phrase for testing, with return its predicted probability
Then create GUI code for:
Getting selected text file from the user. A JFileChooser and supporting code works well here.
Button to start analysis
JTextField to allow entering of phrase
JTextArea or perhaps JTable to display results of analysis
Note that you should avoid having more than one JFrame in your GUI. For more on this, please have a look at The Use of Multiple JFrames, Good/Bad Practice?
I'm doing a Phone Directory project and we have to read from a directory file telnos.txt
I'm using a Scanner to load the data from the file telnos.txt, using a loadData method from a previous question I asked here on StackOverflow.
I noticed attempts to find a user always returned Not Found, so I added a few System.out.printlns in the methods to help me see what was going on. It looks like the scanner isn't reading anything from the file. Weirdly, it is printing the name of the file as what should be the first line read, which makes me think I've missed something very very simple here.
Console
run:
telnos.txt
null
loadData tested successfully
Please enter a name to look up: John
-1
Not found
BUILD SUCCESSFUL (total time: 6 seconds)
ArrayPhoneDirectory.java
import java.util.*;
import java.io.*;
public class ArrayPhoneDirectory implements PhoneDirectory {
private static final int INIT_CAPACITY = 100;
private int capacity = INIT_CAPACITY;
// holds telno of directory entries
private int size = 0;
// Array to contain directory entries
private DirectoryEntry[] theDirectory = new DirectoryEntry[capacity];
// Holds name of data file
private final String sourceName = "telnos.txt";
File telnos = new File(sourceName);
// Flag to indicate whether directory was modified since it was last loaded or saved
private boolean modified = false;
// add method stubs as specified in interface to compile
public void loadData(String sourceName) {
Scanner read = new Scanner("telnos.txt").useDelimiter("\\Z");
int i = 1;
String name = null;
String telno = null;
while (read.hasNextLine()) {
if (i % 2 != 0)
name = read.nextLine();
else
telno = read.nextLine();
add(name, telno);
i++;
}
}
public String lookUpEntry(String name) {
int i = find(name);
String a = null;
if (i >= 0) {
a = name + (" is at position " + i + " in the directory");
} else {
a = ("Not found");
}
return a;
}
public String addChangeEntry(String name, String telno) {
for (DirectoryEntry i : theDirectory) {
if (i.getName().equals(name)) {
i.setNumber(telno);
} else {
add(name, telno);
}
}
return null;
}
public String removeEntry(String name) {
for (DirectoryEntry i : theDirectory) {
if (i.getName().equals(name)) {
i.setName(null);
i.setNumber(null);
}
}
return null;
}
public void save() {
PrintWriter writer = null;
// writer = new PrintWriter(FileWriter(sourceName));
}
public String format() {
String a;
a = null;
for (DirectoryEntry i : theDirectory) {
String b;
b = i.getName() + "/n";
String c;
c = i.getNumber() + "/n";
a = a + b + c;
}
return a;
}
// add private methods
// Adds a new entry with the given name and telno to the array of
// directory entries
private void add(String name, String telno) {
System.out.println(name);
System.out.println(telno);
theDirectory[size] = new DirectoryEntry(name, telno);
size = size + 1;
}
// Searches the array of directory entries for a specific name
private int find(String name) {
int result = -1;
for (int count = 0; count < size; count++) {
if (theDirectory[count].getName().equals(name)) {
result = count;
}
System.out.println(result);
}
return result;
}
// Creates a new array of directory entries with twice the capacity
// of the previous one
private void reallocate() {
capacity = capacity * 2;
DirectoryEntry[] newDirectory = new DirectoryEntry[capacity];
System.arraycopy(theDirectory, 0, newDirectory,
0, theDirectory.length);
theDirectory = newDirectory;
}
}
ArrayPhoneDirectoryTester.java
import java.util.Scanner;
public class ArrayPhoneDirectoryTester {
public static void main(String[] args) {
//create a new ArrayPhoneDirectory
PhoneDirectory newTest = new ArrayPhoneDirectory();
newTest.loadData("telnos.txt");
System.out.println("loadData tested successfully");
System.out.print("Please enter a name to look up: ");
Scanner in = new Scanner(System.in);
String name = in.next();
String entryNo = newTest.lookUpEntry(name);
System.out.println(entryNo);
}
}
telnos.txt
John
123
Bill
23
Hello
23455
Frank
12345
Dkddd
31231
In your code:
Scanner read = new Scanner("telnos.txt");
Is not going to load file 'telnos.txt'. It is instead going to create a Scanner object that scans the String "telnos.txt".
To make the Scanner understand that it has to scan a file you have to either:
Scanner read = new Scanner(new File("telnos.txt"));
or create a File object and pass its path to the Scanner constructor.
In case you are getting "File not found" errors you need to check the current working directory. You could run the following lines and see if you are indeed in the right directory in which the file is:
String workingDir = System.getProperty("user.dir");
System.out.println("Current working directory : " + workingDir);
You need to also catch the FileNotFoundException in the function as follows:
public void loadData(String sourceName) {
try {
Scanner read = new Scanner(new File("telnos.txt")).useDelimiter("\\Z");
int i = 1;
String name = null;
String telno = null;
while (read.hasNextLine()) {
if (i % 2 != 0)
name = read.nextLine();
else {
telno = read.nextLine();
add(name, telno);
}
i++;
}
}catch(FileNotFoundException ex) {
System.out.println("File not found:"+ex.getMessage);
}
}
You are actually parsing the filename not the actual file contents.
Instead of:
new Scanner("telnos.txt")
you need
new Scanner( new File( "telnos.txt" ) )
http://docs.oracle.com/javase/7/docs/api/java/util/Scanner.html
So I have a file that has names along with 11 popularity ranks which looks like this. <--- (this is a link) I am a bit confused on what I am suppose to do with this next part that I have for my assignment. Generally I have a name app that looks like this:
public class Name{
private String givenName;
private int[] ranks = new int[11];
public Name(String name, int[] popularityRanks){
givenName = name;
for (int i = 0; i < 11; i++){
ranks[i] = popularityRanks[i];
}
}
public String getName(){
return givenName;
}
public int getPop(int decade){
if (decade >= 1 && decade <= 11){
return ranks[decade];
}
else{
return -1;
}
}
public String getHistoLine(int decade){
String histoLine = ranks[decade] + ": ";
return histoLine;
}
public String getHistogram(){
String histogram = "";
for (int i = 0; i < 11; i++){
histogram += ranks[i] + ": " + this.getHistoLine(i)
+ "\n";
}
return histogram;
}
}
It is not finished for the getHistoLine but that doesn't have anything to do with what I am trying to do. Generally I want to take these names in from the file and create an array of list.
How he describes it:
Create the array in main, pass it to the readNamesFile method and let that method fill it with Name objects
Test this, by printing out various names and their popularity rankings
For example, if main named the array, list, then upon return from the readNamesFile method do something like:
System.out.println( list[0].getName() + list[0].getPop(1) );
This is what my main looks like:
import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;
public class NameApp{
public static void main(String[] args){
Name list[] = new Name()
}
private static void loadFile(){
Scanner inputStream = null;
String fileName = "names.txt";
try {
inputStream = new Scanner (new File(fileName));
}
catch (FileNotFoundException e){
System.out.println("Error opening file named: " + fileName);
System.out.println("Exiting...");
}
while (inputStream.hasNext()){
}
}
}
I am just a bit confused how I can take the name have it send to the Name object list[] and then take the popularity ranks and send it to the Name object list[]. So when I call
list[0].getName()
it will just call the name for one of the lines... Sorry I am a bit new to the java language. Thanks in advance
You need to create a Name list correctly. I would use a List since you don't know how many names there will be;
public static void main(String[] args){
List<Name> list = new ArrayList<Name>();
loadFile();
System.out.println(list.get(0).getPop());
}
private static void loadFile(){
Scanner inputStream = null;
String fileName = "names.txt";
try {
inputStream = new Scanner (new File(fileName));
}
catch (FileNotFoundException e){
System.out.println("Error opening file named: " + fileName);
System.out.println("Exiting...");
}
while (inputStream.hasNext()){
// givenName = something
// ranks = something;
list.add(new Name(givenName, ranks);
}
}
Assuming each line is something like this (from your deleted comment)
A 1 234 22 43 543 32 344 32 43
Your while loop can be something like this
while (inputStream.hasNextLIne()){
String line = inputStream.nextLine();
String tokens = line.split("\\s+");
String givenName = tokens[0];
int[] numList = new int[tokens.lenth - 1];
for (int i = 1; i < tokens.length; i++){
numList[i - 1] = Integer.parseInt(tokens[i].trim());
}
list.add(new Name(givenName, numList);
}