Develop Reference

Search for multiline String in a text file

I have a text file from which i am trying to search for a String which has multiple lines. A single string i am able to search but i need multi line string to be searched.
I have tried to search for single line which is working fine.
public static void main(String[] args) throws IOException
{
File f1=new File("D:\\Test\\test.txt");
String[] words=null;
FileReader fr = new FileReader(f1);
BufferedReader br = new BufferedReader(fr);
String s;
String input="line one";
// here i want to search for multilines as single string like
// String input ="line one"+
// "line two";
int count=0;
while((s=br.readLine())!=null)
{
words=s.split("\n");
for (String word : words)
{
if (word.equals(input))
{
count++;
}
}
}
if(count!=0)
{
System.out.println("The given String "+input+ " is present for "+count+ " times ");
}
else
{
System.out.println("The given word is not present in the file");
}
fr.close();
}
And below are the file contents.
line one
line two
line three
line four

Use the StringBuilder for that, read every line from file and append them to StringBuilder with lineSeparator
StringBuilder lineInFile = new StringBuilder();
while((s=br.readLine()) != null){
lineInFile.append(s).append(System.lineSeparator());
}
Now check the searchString in lineInFile by using contains
StringBuilder searchString = new StringBuilder();
builder1.append("line one");
builder1.append(System.lineSeparator());
builder1.append("line two");
System.out.println(lineInFile.toString().contains(searchString));

More complicated solution from default C (code is based on code from book «The C programming language» )
final String searchFor = "Ich reiß der Puppe den Kopf ab\n" +
"Ja, ich reiß' ich der Puppe den Kopf ab";
int found = 0;
try {
String fileContent = new String(Files.readAllBytes(
new File("puppe-text").toPath()
));
int i, j, k;
for (i = 0; i < fileContent.length(); i++) {
for (k = i, j = 0; (fileContent.charAt(k++) == searchFor.charAt(j++)) && (j < searchFor.length());) {
// nothig
}
if (j == searchFor.length()) {
++found;
}
}
} catch (IOException ignore) {}
System.out.println(found);

Why don't you just normalize all the lines in the file to one string variable and then just count the number of occurrences of the input in the file. I have used Regex to count the occurrences but can be done in any custom way you find suitable.
public static void main(String[] args) throws IOException
{
File f1=new File("test.txt");
String[] words=null;
FileReader fr = new FileReader(f1);
BufferedReader br = new BufferedReader(fr);
String s;
String input="line one line two";
// here i want to search for multilines as single string like
// String input ="line one"+
// "line two";
int count=0;
String fileStr = "";
while((s=br.readLine())!=null)
{
// Normalizing the whole file to be stored in one single variable
fileStr += s + " ";
}
// Now count the occurences
Pattern p = Pattern.compile(input);
Matcher m = p.matcher(fileStr);
while (m.find()) {
count++;
}
System.out.println(count);
fr.close();
}
Use StringBuilder class for efficient string concatenation.

Try with Scanner.findWithinHorizon()
String pathToFile = "/home/user/lines.txt";
String s1 = "line two";
String s2 = "line three";
String pattern = String.join(System.lineSeparator(), s1, s2);
int count = 0;
try (Scanner scanner = new Scanner(new FileInputStream(pathToFile))) {
while (scanner.hasNext()) {
String withinHorizon = scanner.findWithinHorizon(pattern, pattern.length());
if (withinHorizon != null) {
count++;
} else {
scanner.nextLine();
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
}
System.out.println(count);

Try This,
public static void main(String[] args) throws IOException {
File f1 = new File("./src/test/test.txt");
FileReader fr = new FileReader(f1);
BufferedReader br = new BufferedReader(fr);
String input = "line one";
int count = 0;
String line;
while ((line = br.readLine()) != null) {
if (line.contains(input)) {
count++;
}
}
if (count != 0) {
System.out.println("The given String " + input + " is present for " + count + " times ");
} else {
System.out.println("The given word is not present in the file");
}
fr.close();
}

Replace multiple string in a file java

I am trying to replace multiple strings in a file from source as ArrayList. But the application is erasing the old string before replacing a new one. Please help.
public static void writeNewFile(File template, ArrayList<String> data) {
File file = template;
String nameToReplace = "((name))";
String productToReplace = "((product))";
String giftToReplace = "((gift))";
String giftValueToReplace = "((gift-value))";
String outputFileName = data.get(0);
String workingDirectory = System.getProperty("user.dir");
Scanner scanner = null;
try {
scanner = new Scanner(file);
PrintWriter writer = new PrintWriter(workingDirectory + "\\Output\\" + outputFileName);
while (scanner.hasNextLine()) {
String line1 = scanner.nextLine();
writer.println(line1.replace(nameToReplace, data.get(1)));
writer.println(line1.replace(productToReplace, data.get(2)));
}
} catch (Exception e) {
System.out.println("Destination folder not found");
}
}

This worked for me
try {
BufferedReader reader = new BufferedReader(new FileReader(file));
String line = "", oldtext = "";
while ((line = reader.readLine()) != null) {
oldtext += line + "\r\n";
}
reader.close();
String result = oldtext.replace(nameToReplace, data.get(1))
.replace(productToReplace, data.get(2))
.replace(giftToReplace, data.get(3));
// Write updated record to a file
FileWriter writer = new FileWriter(workingDirectory + "\\Output\\" + outputFileName);
writer.write(result);
writer.close();
} catch (IOException ioe) {
System.out.println("Write error");
}

Move to next element of array

I need the below code to move to next line and not to restart from first line again
public void actionPerformed(ActionEvent e) {
String getTextArea;
getTextArea = textArea.getText();
String[] arr = getTextArea.split("\\n");
String type = null;
String serial = null;
try {
for(String s : arr) {
if(s.isEmpty()) {
textArea_1.append("Empty line" + '\n');
s = getTextArea;
}
type = s.substring(0, 4);
serial = s.substring(5, 12);
URL url = new URL("blablabla" + type + serial);
BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
String result;
Scanner sc;
sc = new Scanner(in);
while(sc.hasNext()) {
result = sc.next();
if (result.contains("Type:")) {
result = sc.nextLine();
result = sc.nextLine();
result = result.substring(26,30);
textArea_1.append(result + '\t');
}
result = sc.nextLine();
result = sc.nextLine();
result = result.substring(26, 29);
textArea_1.append(result + '\t');
}
}
}
} catch (Exception e2) {
// TODO: handle exception
}
}
});
Here is a picture to show the result
As you see after writing empty line the first line is repeated again !

I think that instead of s = getTextArea; in the if block, you should have continue; to advance to the next element in arr.

Reading and modifying the text from the text file in Java

I am have a project that need to modify some text in the text file.
Like BB,BO,BR,BZ,CL,VE-BR
I need make it become BB,BO,BZ,CL,VE.
and HU, LT, LV, UA, PT-PT/AR become HU, LT, LV, UA,/AR.
I have tried to type some code, however the code fail to loop and also,in this case.
IN/CI, GH, KE, NA, NG, SH, ZW /EE, HU, LT, LV, UA,/AR, BB
"AR, BB,BO,BR,BZ,CL, CO, CR, CW, DM, DO,VE-AR-BR-MX"
I want to delete the AR in second row, but it just delete the AR in first row.
I got no idea and seeking for helps.
Please
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.util.Scanner;
public class tomy {
static StringBuffer stringBufferOfData = new StringBuffer();
static StringBuffer stringBufferOfData1 = stringBufferOfData;
static String filename = null;
static String input = null;
static String s = "-";
static Scanner sc = new Scanner(s);
public static void main(String[] args) {
boolean fileRead = readFile();
if (fileRead) {
replacement();
writeToFile();
}
System.exit(0);
}
private static boolean readFile() {
System.out.println("Please enter your files name and path i.e C:\\test.txt: ");
filename = "C:\\test.txt";
Scanner fileToRead = null;
try {
fileToRead = new Scanner(new File(filename));
for (String line; fileToRead.hasNextLine()
&& (line = fileToRead.nextLine()) != null;) {
System.out.println(line);
stringBufferOfData.append(line).append("\r\n");
}
fileToRead.close();
return true;
} catch (FileNotFoundException ex) {
System.out.println("The file " + filename + " could not be found! "+ ex.getMessage());
return false;
} finally {
fileToRead.close();
return true;
}
}
private static void writeToFile() {
try {
BufferedWriter bufwriter = new BufferedWriter(new FileWriter(
filename));
bufwriter.write(stringBufferOfData.toString());
bufwriter.close();
} catch (Exception e) {// if an exception occurs
System.out.println("Error occured while attempting to write to file: "+ e.getMessage());
}
}
private static void replacement() {
System.out.println("Please enter the contents of a line you would like to edit: ");
String lineToEdit = sc.nextLine();
int startIndex = stringBufferOfData.indexOf(lineToEdit);
int endIndex = startIndex + lineToEdit.length() + 2;
String getdata = stringBufferOfData.substring(startIndex + 1, endIndex);
String data = " ";
Scanner sc1 = new Scanner(getdata);
Scanner sc2 = new Scanner(data);
String lineToEdit1 = sc1.nextLine();
String replacementText1 = sc2.nextLine();
int startIndex1 = stringBufferOfData.indexOf(lineToEdit1);
int endIndex1 = startIndex1 + lineToEdit1.length() + 3;
boolean test = lineToEdit.contains(getdata);
boolean testh = lineToEdit.contains("-");
System.out.println(startIndex);
if (testh = true) {
stringBufferOfData.replace(startIndex, endIndex, replacementText1);
stringBufferOfData.replace(startIndex1, endIndex1 - 2,
replacementText1);
System.out.println("Here is the new edited text:\n"
+ stringBufferOfData);
} else {
System.out.println("nth" + stringBufferOfData);
System.out.println(getdata);
}
}
}

I wrote a quick method for you that I think does what you want, i.e. remove all occurrences of a token in a line, where that token is embedded in the line and is identified by a leading dash.
The method reads the file and writes it straight out to a file after editing for the token. This would allow you to process a huge file without worrying about about memory constraints.
You can simply rename the output file after a successful edit. I'll leave it up to you to work that out.
If you feel you really must use string buffers to do in memory management, then grab the logic for the line editing from my method and modify it to work with string buffers.
static void onePassReadEditWrite(final String inputFilePath, final String outputPath)
{
// the input file
Scanner inputScanner = null;
// output file
FileWriter outputWriter = null;
try
{
// open the input file
inputScanner = new Scanner(new File(inputFilePath));
// open output file
File outputFile = new File(outputPath);
outputFile.createNewFile();
outputWriter = new FileWriter(outputFile);
try
{
for (
String lineToEdit = inputScanner.nextLine();
/*
* NOTE: when this loop attempts to read beyond EOF it will throw the
* java.util.NoSuchElementException exception which is caught in the
* containing try/catch block.
*
* As such there is NO predicate required for this loop.
*/;
lineToEdit = inputScanner.nextLine()
)
// scan all lines from input file
{
System.out.println("START LINE [" + lineToEdit + "]");
// get position of dash in line
int dashInLinePosition = lineToEdit.indexOf('-');
while (dashInLinePosition != -1)
// this line has needs editing
{
// split line on dash
String halfLeft = lineToEdit.substring(0, dashInLinePosition);
String halfRight = lineToEdit.substring(dashInLinePosition + 1);
// get token after dash that is to be removed from whole line
String tokenToRemove = halfRight.substring(0, 2);
// reconstruct line from the 2 halves without the dash
StringBuilder sb = new StringBuilder(halfLeft);
sb.append(halfRight.substring(0));
lineToEdit = sb.toString();
// get position of first token in line
int tokenInLinePosition = lineToEdit.indexOf(tokenToRemove);
while (tokenInLinePosition != -1)
// do for all tokens in line
{
// split line around token to be removed
String partLeft = lineToEdit.substring(0, tokenInLinePosition);
String partRight = lineToEdit.substring(tokenInLinePosition + tokenToRemove.length());
if ((!partRight.isEmpty()) && (partRight.charAt(0) == ','))
// remove prefix comma from right part
{
partRight = partRight.substring(1);
}
// reconstruct line from the left and right parts
sb.setLength(0);
sb = new StringBuilder(partLeft);
sb.append(partRight);
lineToEdit = sb.toString();
// find next token to be removed from line
tokenInLinePosition = lineToEdit.indexOf(tokenToRemove);
}
// handle additional dashes in line
dashInLinePosition = lineToEdit.indexOf('-');
}
System.out.println("FINAL LINE [" + lineToEdit + "]");
// write line to output file
outputWriter.write(lineToEdit);
outputWriter.write("\r\n");
}
}
catch (java.util.NoSuchElementException e)
// end of scan
{
}
finally
// housekeeping
{
outputWriter.close();
inputScanner.close();
}
}
catch(FileNotFoundException e)
{
e.printStackTrace();
}
catch(IOException e)
{
inputScanner.close();
e.printStackTrace();
}
}

Extracing and assigning values from a text file to variable - Java

I am having trouble assigning values from text file to 4 variables. The file has four values in each line which are separated by space. I want to assign each value to a different variable.
the data in the items.txt:
344443 toothbrush WW WQ
243434 ToothPaste WE WQ
349343 DentalFloss WS QA
This is my code which isnt working.
File itemsSold = new File("items.txt");
if (itemsSold.exists()){
Scanner inputFile = new Scanner(itemsSold);
while (inputFile.hasNextLine()) {
Items = inputFile.nextLine();
ItemId = inputFile.nextInt();
ItemName = inputFile.next();
String itemShlve = inputFile.next();
String itemcode= inputFile.next();
System.out.print(ItemId + "\n");
System.out.print(ItemName);
System.out.print(itemitemShlve);
}
inputFile.close();
}
Output needed is this, which what I get:
344443
toothbrush
WW
243434
ToothPaste
WE
349343
DentalFloss
WS
A beginner to Java, Thanks in advance.

You can do this:
Scanner fScn = new Scanner(new File(“items.txt”));
String data;
while( fScn.hasNextLine() ){
data = fScn.nextLine();
String[] token = data.split(" ");
itemId = Integer.parseInt(token[0]);
itemName= token[1];
itemShelve = token[2];
itemCode = token[3];
}
fScn.close();
1) Use file Scanner to capture data line by line
2) Split the line of data into tokens by white spaces
3) Assign the tokens accordingly into respective variables
4) Close file Scanner

Don't mix calls to nextInt and nextLine. Just use nextLine in this case.

Use another Scanner for each line.
if (itemsSold.exists()){
Scanner inputFile = new Scanner(itemsSold);
while (inputFile.hasNextLine()) { // check for next line
Items = inputFile.nextLine(); // read next line
Scanner scanner = new Scanner(Items);//create new Scanner for new line
ItemId = scanner.nextInt(); // read next int
ItemName = scanner.next();
String itemShlve = scanner.next();
String itemcode= scanner.next();
scanner.close(); // don't forget to close the Scanner
...
}
inputFile.close();
}
Note: Follow Java Naming convention.

I hope it will help. If you want fourth value also. Set the value 4 in the SysOut Loop.
File file = new File("C:\\items.Txt");
String[] variable = new String[4];
try {
FileReader fr = new FileReader(file);
BufferedReader br = new BufferedReader(fr);
String line;
int count;
String temp = new String();
while((line = br.readLine())!=null) {
count = 0;
for(char c : line.toCharArray()) {
if(c ==' ') {
variable[count] = temp;
temp = new String();
count++;
}
else {
temp += c;
}
}
for(int i=0; i<3; i++) {
System.out.println(variable[i]);
}
System.out.println();
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
br.close()
fr.close();