I am going through a project where I need to remove all java keywords from a java file. First I create a keyword.java file and store all java keywords into this file.Like abstract continue for new switch assert default goto package etc which I store keyword.java file. I have another file named newFile.java and I read all data from newFile.java as a String. I have to remove all java keywords from newFile.java file. As far I tried:
public void processFile() throws IOException {
String data = "";
data = new String(Files.readAllBytes(Paths.get("H:\\java\\Clone\\newFile.java"))).trim();
String rmvPunctuation = removePunctuation(data);
String newLineRemove = rmvPunctuation.replace("\n", "").replace("\r", "");
String spaceRemove = newLineRemove.replaceAll("( ){2,}", " ");
removeKeyword(spaceRemove);}
public void removeKeyword(String fileAsString) throws FileNotFoundException, IOException {
ArrayList<String> keyWordList = new ArrayList<>();
ArrayList<String> methodContentList = new ArrayList<>();
FileInputStream fis = new FileInputStream("H:\\java\\keyword.java");
byte[] b = new byte[fis.available()];
fis.read(b);
String[] keyword = new String(b).trim().split(" ");
String newString = "";
for (int i = 0; i < keyword.length; i++) {
keyWordList.add(keyword[i].trim());
}
String[] p = fileAsString.split(" ");
for (int i = 0; i < p.length; i++) {
if (!(keyWordList.contains(p[i].trim()))) {
newString = newString + p[i] + " ";
}
}
System.out.println("" + newString);
}
But I could not found my desired output. All the java keywords are not removed from newFile.java file. I think StackOverflow community help me to solve this. I am also a beginner.
I also tried:
public void removeKeyword(String fileAsString) throws IOException {
String keyWord = new String(Files.readAllBytes(Paths.get("H:\\java\\keyword.java"))).trim();
String text = fileAsString.trim();
ArrayList<String> wordList = new ArrayList<>();
ArrayList<String> keyWordList = new ArrayList<>();
wordList.addAll(Arrays.asList(text.split(" ")));
keyWordList.addAll(Arrays.asList(keyWord.split(" ")));
wordList.removeAll(keyWordList);
System.out.println("" + wordList.toString());
}
I am facing a problem in reading data from the text file line by line storing it in an arraylist. I have to read the data from arraylist[0] and I have to perform split operation on that data and I have to store the data in a different array.
public class StatsOnData {
public static void main(String args[]) throws IOException {
String gender;
BufferedReader in = new BufferedReader(new FileReader("file path"));
String str;
List<String> list = new ArrayList<String>();`enter code here`
while((str = in.readLine()) != null){
list.add(str);
}
String[] stringArr = list.toArray(new String[0]);
System.out.println(list.size());
//spliting the array into a sub array
StringBuilder temp = new StringBuilder();
for(int i=1; i <= list.size(); i++){
for( int j = 0; j < list[i]; j++){
String line = null;
while ((line = .readLine()) != null) {
String[] values = line.split("|");
for (String str1 : values) {
System.out.println(str);
}
}
}
I did not understand your problem but may be you want to do something like this -
BufferedReader in = new BufferedReader(new FileReader("file path"));
String str;
int countMale=0;
int countFemale=0;
List<String> list = new ArrayList<String>();
while((str = in.readLine()) != null){
list.add(str);
}
for(String s:list){
String[] splitValues=s.split("|");
for(int i=0;i<splitValues.length;i++){
if(splitValues[i].equalsIgnoreCase("m")){
countMale++;
}
else if(splitValues[i].equalsIgnoreCase("f")){
countFemale++;
}
}
}
System.out.println("Number of males: "+countMale);
System.out.println("Number of females: "+countFemale);
Hope this helps !
To print content of each line in split form,
for(int i=1; i <= list.size(); i++)
{
String line = list.get (i) ;
String[] values = line.split("|");
for (String str1 : values)
{
System.out.print(str);
}
}
You can even use map
Map<String,List<String>> genderNameList = new HashMap<String,List<String>>();
for(int i=1; i <= list.size(); i++)
{
String line = list.get (i) ;
String[] values = line.split("|");
//assuming it won't be null
genderNameList.get ( values[1]).add(values[0]);// need tot take care about null
}
If your string goes like peter||Mr|F||23
List<Person> listOfObj = new ArrayList<Person> ();
for(int i=1; i <= list.size(); i++)
{
String line = list.get (i) ;
String[] values = line.split("|");
//assuming it won't be null
Person p = new Person ( values) ;
}
And person can be as following :
Class Person {
private String name;
private String gender;
private int age;
//provide gettter and setter for all such fields.
Person ( String [] values)
{
name = values[0];
gender = values[1];
age = Integer.valuesOf ( values[2]) ;
....
}
}
Here I read the dataset and extracted the data lines(not the attributes) and print it.Next I need to sort the dataset.Now this is stored in an ArrayList.How to sort it?
public static void main(String args[]) throws Exception
{
String filen, jsnfl;
Customiseddata data = new Customiseddata();
data.setAlgorithm("C4.5");
data.setUserName("Dahlia");
System.out.println("Enter the file name");
sc = new Scanner(System.in);
filen = sc.nextLine();
data.setFileName("input_files/" + filen);
Mainclass main = new Mainclass();
main.build(data);
}
public void build(Customiseddata data) throws Exception
{
int extension;
String filename;
filename = data.getFileName();
extension = filename.lastIndexOf('.');
String extensionType = filename.substring(extension + 1,
filename.length());
if (extensionType.equalsIgnoreCase("csv"))
{
readcsv(filename);
}
else if (extensionType.equalsIgnoreCase("arff"))
{
readarff(filename);
}
}
public void readarff(String filename) throws Exception
{
#SuppressWarnings("unused")
int filesize, attributesize, c = 0, i;
#SuppressWarnings("unused")
float v = 0;
String s, line1;
ArrayList<String> filelines;
ArrayList<String> attributes;
Customiseddata data = new Customiseddata();
Arfffilereader arfffile = new Arfffilereader();
Extractdata exdata = new Extractdata();
exdata = arfffile.extractInputArff(filename);
filelines = exdata.getFileLines();
attributes = exdata.getAttributes();
filesize = filelines.size();
attributesize = attributes.size();
data.setFilesize(filesize);
System.out.println("Print the attributes");
System.out.println("--------------------");
for (i = 0; i < attributesize; i++)
{
System.out.println(attributes.get(i));
}
System.out.println("\t");
System.out.println("Print the filelines");
System.out.println("--------------------");
for (int j = 0; j < filesize; j++)
{
System.out.println(filelines.get(j));
}
}
But after this I need to sort the dataset.
Since the elements of the list are Strings and since String implements Comparable, sorting a list is as simple as:
Collections.sort(theList);
Note however that it will sort the list in place. If you don't want that, make a copy of the list and sort that copy.
So I have a text file with items like look like this:
350279 1 11:54 107.15
350280 3 11:55 81.27
350281 2 11:57 82.11
350282 0 11:58 92.43
350283 3 11:59 86.11
I'm trying to create arrays from those values, in which the first values of each line are in an array, the second values of each line are in an array, and so on.
This is all the code I have right now, and I can't seem to figure out how to do it.
package sales;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class Sales {
public static void main (String[] args) throws FileNotFoundException {
Scanner reader = new Scanner(new File("sales.txt"));
int[] transID = new int[reader.nextInt()];
int[] transCode = new int[reader.nextInt()];
String[] time = new String[reader.next()];
double[] trasAmount = new double[reader.hasNextDouble()];
}
}
It's difficult to build an array this way, because Arrays have fixed size... you need to know how many elements they have. If you use a List instead, you don't have to worry about knowing the number of elements in advance. Try this (note: there is no error checking here!):
public static void main (String[] args) throws FileNotFoundException {
Scanner reader = new Scanner(new File("sales.txt"));
List<Integer> ids = new LinkedList<>();
List<Integer> codes = new LinkedList<>();
List<String> times = new LinkedList<>();
List<Double> amounts = new LinkedList<>();
// Load elements into Lists. Note: you can just use the lists if you want
while(reader.hasNext()) {
ids.add(reader.nextInt());
codes.add(reader.nextInt());
times.add(reader.next());
amounts.add(reader.nextDouble());
}
// Create arrays
int[] idArray = new int[ids.size()];
int[] codesArray = new int[codes.size()];
String[] timesArray = new String[times.size()];
double[] amountsArray = new double[amounts.size()];
// Load elements into arrays
int index = 0;
for(Integer i : ids) {
idArray[index++] = i;
}
index = 0;
for(Integer i : codes) {
codesArray[index++] = i;
}
index = 0;
for(String i : times) {
timesArray[index++] = i;
}
index = 0;
for(Double i : ids) {
amountsArray[index++] = i;
}
}
Use Array list because Arrays have fixed size and using Arraylist you add the elements dynamically
Scanner reader = new Scanner(new File("test.txt"));
List<Integer> transID = new ArrayList<Integer>();
List<Integer> transCode = new ArrayList<Integer>();
List<String> time= new ArrayList<String>();
List<Double> trasAmount = new ArrayList<Double>();
while(reader.hasNext() )
{
transID.add(reader.nextInt());
transCode.add(reader.nextInt());
time.add(reader.next());
trasAmount.add(reader.nextDouble());
}
System.out.println(transID.toString());
System.out.println(transCode.toString());
System.out.println(time.toString());
System.out.println(trasAmount.toString());
Output of the above code
transID [350279, 350280, 350281, 350282, 350283]
transCode [1, 3, 2, 0, 3]
time [11:54, 11:55, 11:57, 11:58, 11:59]
trasAmount [107.15, 81.27, 82.11, 92.43, 86.11]
You'll need a while loop to check for input. Since not all inputs are integers you might do something like:
while(reader.hasNextLine()){ //checks to make sure there's still a line to be read in the file
String line=reader.nextLine(); //record that next line
String[] values=line.split(" "); //split on spaces
if(values.length==4){
int val1=Integer.parseInt(values[0]); //parse values
int val2=Integer.parseInt(values[1]);
String val3=values[2];
double val4=Double.parseDouble(values[3]);
//add these values to your arrays. Might have to "count" the number of lines on a first pass and then run through a second time... I've been using the collections framework for too long to remember exactly how to work with arrays in java when you don't know the size right off the bat.
}
}
In addition to my comment here are 3 ways how you cant do it
read into single arrays
int size = 2;
// first allocate some memory for each of your arrays
int[] transID = new int[size];
int[] transCode = new int[size];
String[] time = new String[size];
double[] trasAmount = new double[size];
Scanner reader = new Scanner(new File("sales.txt"));
// keep track of how many elements you have read
int i = 0;
// start reading and continue untill there is no more left to read
while(reader.hasNext()) {
// since array size is fixed and you don't know how many line your file will have
// you have to reallocate your arrays when they have reached their maximum capacity
if(i == size) {
// increase capacity by 5
size += 5;
// reallocate temp arrays
int[] tmp1 = new int[size];
int[] tmp2 = new int[size];
String[] tmp3 = new String[size];
double[] tmp4 = new double[size];
// copy content to new allocated memory
System.arraycopy(transID, 0, tmp1, 0, transID.length);
System.arraycopy(transCode, 0, tmp2, 0, transCode.length);
System.arraycopy(time, 0, tmp3, 0, time.length);
System.arraycopy(trasAmount, 0, tmp4, 0, trasAmount.length);
// reference to the new memory by your old old arrays
transID = tmp1;
transCode = tmp2;
time = tmp3;
trasAmount = tmp4;
}
// read
transID[i] = Integer.parseInt(reader.next());
transCode[i] = Integer.parseInt(reader.next());
time[i] = reader.next();
trasAmount[i] = Double.parseDouble(reader.next());
// increment for next line
i++;
}
reader.close();
for(int j = 0; j < i; j++) {
System.out.println("" + j + ": " + transIDList.get(j) + ", " + transCodeList.get(j) + ", " + timeList.get(j) + ", " + trasAmountList.get(j));
}
as you see this is a lot of code.
Better you use lists so get rid of the overhead of reallocation and copying (at leas in your own code)
read into single lists
// instanciate your lists
List<Integer> transIDList = new ArrayList<>();
List<Integer> transCodeList = new ArrayList<>();
List<String> timeList = new ArrayList<>();
List<Double> trasAmountList = new ArrayList<>();
reader = new Scanner(new File("sales.txt"));
int i = 0;
while(reader.hasNext()) {
// read
transIDList.add(Integer.parseInt(reader.next()));
transCodeList.add(Integer.parseInt(reader.next()));
timeList.add(reader.next());
trasAmountList.add(Double.parseDouble(reader.next()));
i++;
}
reader.close();
for(int j = 0; j < i; j++) {
System.out.println("" + j + ": " + transIDList.get(j) + ", " + transCodeList.get(j) + ", " + timeList.get(j) + ", " + trasAmountList.get(j));
}
You see here how small the code went? But but it still can get better...
A line in the sales.txt file seem to constitute data elements of some entity, why not put them in an object ? for that you may write a class named Trans, some think like this:
class Trans {
public int transID;
public int transCode;
public String time;
public double trasAmount;
#Override
public String toString() {
return transID + ", " + transCode + ", " + time + ", " + trasAmount;
}
}
Then you can use this class to hold the data you read from your file and put each object of that class in a list.
reading into a list of objects
reader = new Scanner(new File("sales.txt"));
List<Trans> transList = new ArrayList<>();
int i = 0;
while(reader.hasNext()) {
Trans trans = new Trans();
trans.transID = Integer.parseInt(reader.next());
trans.transCode = Integer.parseInt(reader.next());
trans.time = reader.next();
trans.trasAmount = Double.parseDouble(reader.next());
transList.add(trans);
i++;
}
reader.close();
for(Trans trans : transList) {
System.out.println("" + i++ + ": " + trans);
}
Output of all 3 methods
0: 350279, 1, 11:54, 107.15
1: 350280, 3, 11:55, 81.27
2: 350281, 2, 11:57, 82.11
3: 350282, 0, 11:58, 92.43
4: 350283, 3, 11:59, 86.11
Here is a sample code to read the values from the file and write into an array. Sample code has logic for int array, you can replicate it for other array types as well.
package sales;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
public class Sales {
public static void main (String[] args) throws IOException {
FileInputStream fstream = new FileInputStream("sales.txt");
BufferedReader br = new BufferedReader(new InputStreamReader(fstream));
String strLine;
while ((strLine = br.readLine()) != null) {
String[] tokens = strLine.split(" ");
int[] transID = convertStringToIntArray(tokens[0]);
for(int i = 0 ; i < transID.length ; i++ )
System.out.print(transID[i]);
}
}
/** function to convert a string to integer array
* #param str
* #return
*/
private static int[] convertStringToIntArray(String str) {
int intArray[] = new int[str.length()];
for (int i = 0; i < str.length(); i++) {
intArray[i] = Character.digit(str.charAt(i), 10);
}
return intArray;
}
}
I have an array that is from .split command and want to put it into an array called String[][] datatabvars, I do not know how to turn datatabvars into a two dimensional array and put the data into it.
public String[] getList() {
String file_name = "path";
String[] links = null;
String[][] datatabvars = null; // this var
int numberOfDatatabs = 0;
try {
ReadFile file = new ReadFile(file_name);
String[] aryLines = file.OpenFile();
int i;
for(i=0; i < aryLines.length; i++) { //aryLines.length
if (aryLines[i].substring(0, 7).equals("datatab")) {
aryLines[i] = aryLines[i].replace("datatab["+Integer.toString(numberOfDatatabs)+"] = new Array(", "");
aryLines[i] = aryLines[i].replace(");", "");
datatabvars = aryLines[i].split(","); // this split array
numberOfDatatabs++;
}
}
System.out.println(datatabvars[0]);
}catch (IOException e) {
System.out.println( e.getMessage() );
}
return links;
}
Update the two lines(I added comment) as below: (I am assuming that rest of your code is working)
String[][] datatabvars = null; // this var
int numberOfDatatabs = 0;
try {
ReadFile file = new ReadFile(file_name);
String[] aryLines = file.OpenFile();
datatabvars = new String[aryLines.length][]; // INITIALIZED
int i;
for(i=0; i < aryLines.length; i++) { //aryLines.length
if (aryLines[i].substring(0, 7).equals("datatab")) {
aryLines[i] = aryLines[i].
replace("datatab["+Integer.toString(numberOfDatatabs)+"] =
new Array(", "");
aryLines[i] = aryLines[i].replace(");", "");
datatabvars[i] = aryLines[i].split(","); // this split array: ASSIGNED
numberOfDatatabs++;
}
}
System.out.println(datatabvars[0]);
In general, arrays are to avoided like the plague - use collections if possible:. In this case, split() returns a String[], so use that, but use List<String[]> to store multiple String[]:
List<String[]> datatabvars = new ArrayList<String[]>();
...
String[] array = input.split(",");
datatabvars.add(array);
You find life is much easier using collections than arrays.