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How to get my delete function to delete an entire line that contains what I entered, as opposed to just what I entered?

I have a function that adds, searches, and deletes lines from a text file. The Search works irrelevant of case and has a .contains which allows it to work on less than the whole line. The delete function only deletes the exact match. I'm accessing an outside .txt file which is saving the changes that are made.
I tried duplicating my search code, but was unable to produce the same result. I'd also like to completely remove the line so that my table remains clean looking if I don't delete that last entry, but that's less important.
System.out.println("What would you like to delete");
Scanner deleteScanner = new Scanner(System.in);
String deleteInput = deleteScanner.nextLine();
try{
File file = new File("contacts.txt");
File temp = File.createTempFile("file", ".txt",
file.getParentFile());
BufferedReader reader = new BufferedReader(new
InputStreamReader(new FileInputStream(file)));
PrintWriter writer = new PrintWriter(new
OutputStreamWriter(new FileOutputStream(temp)));
for (String line; (line = reader.readLine()) != null;) {
line = line.replace(deleteInput, "");
writer.println(line);
}
reader.close();
writer.close();
file.delete();
temp.renameTo(file);
} catch (IOException e){
e.printStackTrace();
}
I feel like .contains should work but I haven't been able to make it function as intended.

You could get all file lines easier by using:
List<String> lines = Files.readAllLines(Paths.get(path), Charset.defaultCharset());
After that you can simple iterate thru the lines List and delete the whole line if it contains deleteInput:
for (String line : lines) {
if (line.contains(deleteInput)) {
lines.remove(line);
}
}
If there is a need to find the occupies ignoring case you can use toLowerCase() before each check.

Using BufferedWriter and the newLine attribute to insert a line after a string of text

First off I am new at coding in java. I have done extensive research prior to posting this question but have not found the exact answer to my question. I am sure it is my lack of experience, but any assistance the community can provide would be much appreciated.
I am trying to debug a utility class that I have coded. The code is working except for the bit about adding a new line to the substituted text.
Here is the piece of code that is generating an error in NetBeans IDE. The error is incompatible types: Boolean can't be converted to int
try (BufferedWriter bw = new BufferedWriter(new FileWriter (NewCSVFile),true))
What I am trying to do is get this code to read a CSV text file, substitute and the write the new csv data to a new file but preserve the original new lines in the file. And, I want to ensure that the method used is platform independent thus why I am using BufferedWriter.
Here is all the code for your review.
public class TxtFileConverter {
public static void main (String[] args) {
// Location of the file you want to work with.
File CSVFile = new File("/Users/data.csv");
File NewCSVFile = new File("/Users/NewData.csv");
String search = "[,](?!\\w)";
String replace = ",0";
try{
FileReader fr = new FileReader(CSVFile);
String s;
String totalStr = "";
try (BufferedReader br = new BufferedReader(fr)) {
while ((s = br.readLine()) != null) {
totalStr += s;
}
totalStr = totalStr.replaceAll(search, replace);
try (BufferedWriter bw = new BufferedWriter(new FileWriter
(NewCSVFile),true)) {
bw.write(totalStr);
bw.newLine();
}
}
}catch(IOException e){
}
}
}

I think you are trying to read some lines from a file and write it to another file. In the output file, you get all the code in a single line.
I think the bug is in this piece of code.
while ((s = br.readLine()) != null) {
totalStr += s;
}
If you add a statement to add a new line character after reading a line from input file, you should get the desired output.
while ((s = br.readLine()) != null) {
totalStr += s;
totalStr += "\n";
}
The following code adds a newline character at the end of the file.
bw.newLine();

What do you think that true argument is doing in the BufferedWriter constructor? The second and optional argument is the buffer size, an integer. You probably don't even need to supply that argument unless you're doing something rather odd.
try (BufferedWriter bw = new BufferedWriter(new FileWriter(NewCSVFile)))

BufferedWriter has only two constructors:
public BufferedWriter(Writer out) //sz = defaultCharBufferSize = 8192
public BufferedWriter(Writer out, int sz) //sz Output-buffer size, a positive integer
There is no option with second boolean argument. I recommend to use first constructor in your case.

Why does introducing a FileWriter delete all the content in the file?

I have a text file with some text in it and i'm planning on replacing certain characters in the text file. So for this i have to read the file using a buffered reader which wraps a file reader.
File file = new File("new.txt");
BufferedReader br = new BufferedReader(new FileReader(file));
String line = null;
while ((line = br.readLine()) != null) {
System.out.println(line);
}
But since i have to edit characters i have to introduce a file writer and add the code which has a string method called replace all. so the overall code will look as given below.
File file = new File("new.txt");
FileWriter fw = new FileWriter(file);
BufferedReader br = new BufferedReader(new FileReader(file));
String line = null;
while ((line = br.readLine()) != null) {
System.out.println(line);
fw.write(br.readLine().replaceAll("t", "1") + "\n");
}
Problem is when i introduce a file writer to the code (By just having the initialization part and when i run the program it deletes the content in the file regardless of adding the following line)
fw.write(br.readLine().replaceAll("t", "1") + "\n");
Why is this occurring? am i following the correct approach to edit characters in a text file?
Or is there any other way of doing this?
Thank you.

public FileWriter(String fileName,
boolean append)
Parameters:
fileName - String The system-dependent filename.
append - boolean if true, then data will be written to the end of the
file rather than the beginning.
To append data use
new FileWriter(file, true);

The problem is that you're trying to write to the file while you're reading from it. A better solution would be to create a second file, put the transformed data into it, then replace the first file with it when you're done. Or if you don't want to do that, read all of the data out of the file first, then open it for writing and write the transformed data.
Also, have you considered using a text-processing language solution such as awk, sed or perl: https://unix.stackexchange.com/questions/112023/how-can-i-replace-a-string-in-a-files

You need to read the file first, and then, only after you read the entire file, you can write to it.
Or you open a different file for writing and then afterwards you replace the old file with the new one.
The reason is that once you start writing to a file, it is truncated (the data that was in the file is deleted).
The only way to avoid that is to open the file in "append" mode. With that mode, you start writing at the end of the file, so you don't delete its content. However, you won't be able to modify the existing content, you will only add content.

Maybe like this
public static void main(String[] args) throws IOException {
try {
File file = new File("/Users/alexanderkrum/IdeaProjects/printerTest/src/atmDep.txt");
Scanner myReader = new Scanner(file);
ArrayList<Integer> numbers = new ArrayList<>();
while (myReader.hasNextLine()) {
numbers.add(myReader.nextInt() + 1);
}
myReader.close();
FileWriter myWriter = new FileWriter(file);
for (Integer number :
numbers) {
myWriter.write(number.toString() + '\n');
}
myWriter.close();
} catch (FileNotFoundException e) {
System.out.println("An error occurred.");
e.printStackTrace();
}
}

Just add at last :
fw.close();
this will close it ,then it will not delete anything in the file.
:)

How can I get this buffered writer to write one line at a time? JAVA

I am creating a little program that will amend driver letters saved in a program file. The method works in the sense that it locates the file correctly and amends the drive letter correctly.
However when I open the file after it has been changed all the Directory listings are all on one line but they need to be 1 directory per line. I've tried saving each individual line to an Array List then printing them out like that but that didn't seem to work for me so was wondering if anyone could help?
Much appreciated.
P.S. Been messing around trying to make it work and also now ran into another issue where it is now printing them all out into one line but with spaces in between e.g:
S:\ D A T A\ S A G E\
public class copy
{
private String newDriveLetter;
private String line;
private Path[]sageFolders;
private FileReader fileReader;
private BufferedReader bufferedReader;
private FileWriter fileWriter;
private BufferedWriter bufferedWriter;
private List<String> lines = new ArrayList<String>();
public void scanFiles() throws IOException{
try
{
System.out.println("Sage 2015 is Installed on this machine");
File companyFile = new File(sageFolders[8] + "\\COMPANY");
fileReader = new FileReader(companyFile);
bufferedReader = new BufferedReader(fileReader);
while((line = bufferedReader.readLine()) != null)
{
if(line.contains("F"))
{
line = line.replace("F:\\","S:\\");
lines.add(line);
}
}
//Close the Readers
fileReader.close();
bufferedReader.close();
fileWriter = new FileWriter(companyFile);
bufferedWriter = new BufferedWriter(fileWriter);
for(String s : lines)
{
bufferedWriter.write(s);
}
bufferedWriter.flush();
bufferedWriter.close();
}
catch(FileNotFoundException e)
{
System.out.println("File not Found: Moving onto next Version");
}
}

The problem is that readLine() reads a whole line, and then tosses away the line ending. From the documentation:
A String containing the contents of the line, not including any line-termination characters, or null if the end of the stream has been reached
So you have to add it back again, possibly using the preferred line ending for your platform:
bufferedWriter.write(String.format("%s%n", s);
here %s is the String and %n is the platform dependent line ending.
Alternatively, as Ransom Briggs indicates, you may use newline(). newLine() is easier to read and will perform slightly better:
bufferedWriter.write(s);
bufferedWriter.newLine();
I've left the String.format method in as it is a more general approach of adding newlines to strings.

Try PrintWriter - so new PrintWriter(bufferedWriter).println(s).

Add this after bufferedWriter.write(s);:
bufferedWriter.write(System.getProperty("line.separator", "\n"));
This will add the system specific line separator, or "\n" if the system property is not set.

Java - open txt file and clear all multiple spaces

I have a txt file and what I am trying to do is open it and delete all multiple spaces so they become only one. I use:
br = new BufferedReader(new FileReader("C:\\Users\\Chris\\Desktop\\file_two.txt"));
bw = new BufferedWriter(new FileWriter("C:\\Users\\Chris\\Desktop\\file_two.txt"));
while ((current_line = br.readLine()) != null) {
//System.out.println("Here.");
current_line = current_line.replaceAll("\\s+", " ");
bw.write(current_line);
}
br.close();
bw.close();
However, as it seems correct according to me at least, nothing is written on the file. If I use a system.out.println command, it is not printed, meaning that execution is never in the while loop... What do I do wrong? Thanks

you are reading the file and at the same time writing contents on it..it is not allowed...
so better way to read the file first and store the processed text in another file and finally replace the original file with the new one..try this
br = new BufferedReader(new FileReader("C:\\Users\\Chris\\Desktop\\file_two.txt"));
bw = new BufferedWriter(new FileWriter("C:\\Users\\Chris\\Desktop\\file_two_copy.txt"));
String current_line;
while ((current_line = br.readLine()) != null) {
//System.out.println("Here.");
current_line = current_line.replaceAll("\\s+", " ");
bw.write(current_line);
bw.newLine();
}
br.close();
bw.close();
File copyFile = new File("C:\\Users\\Chris\\Desktop\\file_two_copy.txt");
File originalFile = new File("C:\\Users\\Chris\\Desktop\\file_two.txt");
originalFile.delete();
copyFile.renameTo(originalFile);
it may help...

There are few problems with your approach:
Main one is that you are trying to read and write to same file at the same time.
other is that new FileWriter(..) always creates new empty file which kind of prevents FileReader from reading anything from your file.
You should read content from file1 and write its modified version in file2. After that replace file1 with file2.
Your code can look more or less like
Path input = Paths.get("input.txt");
Path output = Paths.get("output.txt");
List<String> lines = Files.readAllLines(input);
lines.replaceAll(line -> line.replaceAll("\\s+", " "));
Files.write(output, lines);
Files.move(output, input, StandardCopyOption.REPLACE_EXISTING);

You must read first then write, you are not allowed to read and write to the same file at the same time, you would need to use RandomAccessFile to do that.
If you don't want to learn a new technique, you will need to either write to a separate file, or cache all lines to memory(IE an ArrayList) but you must close the BufferedReader before you Initialize your BufferedWriter, or it will get a file access error.
Edit:
In case you want to look into it, here is a RandomAccessFile use case example for your intended use. It is worth pointing out this will only work if the final line length is less than or equal to the original, because this technique is basically overwriting the existing text, but should be very fast with a small memory overhead and would work on extremely large files:
public static void readWrite(File file) throws IOException{
RandomAccessFile raf = new RandomAccessFile(file, "rw");
String newLine = System.getProperty("line.separator");
String line = null;
int write_pos = 0;
while((line = raf.readLine()) != null){
line = line.replaceAll("\\s+", " ") + newLine;
byte[] bytes = line.getBytes();
long read_pos = raf.getFilePointer();
raf.seek(write_pos);
raf.write(bytes, 0, bytes.length);
write_pos += bytes.length;
raf.seek(read_pos);
}
raf.setLength(write_pos);
raf.close();
}