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Java writing file line by line

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  1. Writing to a text file line by line
  2. Writing to a text file line by line
  3. Java How to write to a text file
  4. Files.write() : appending new lines in a text file
  5. How to write text to a next empty line in text file in java
  6. How to Write to File Line by Line in Java with Examples
  7. Java write to file line by line using FileOutputStream class
  8. Example : Write to file line by line using FileOutputStream class
  9. Java write to file line by line using FileWriter class
  10. Example : Write to file line by line using FileWriter class
  11. Java write to file line by line using PrintWriter class
  12. Example : Write to file line by line using PrintWriter class
  13. OutputStreamWriter class
  14. OutputStreamWriter class Example:
  15. Java write to file line by line using BufferedWriter
  16. Example : Write to file line by line using BufferedWriter
  17. Conclusion
  18. Newsletter Updates
  19. Newsletter
  20. Recent Posts
  21. java write to file line by line
  22. How do you write multiple lines in a text file in Java?
  23. Will FileWriter create a file?
  24. How do you clear a text file in Java?
  25. How do I change the first line of a file in Java?
  26. How do I change the content of a text file in Java?
  27. How do you read a specific line in a text file in Java?
  28. How do you write to a file?
  29. How do you write Java code?
  30. How do I create a Java file?

Writing to a text file line by line

The output shows the following as a single line: What I expect is to have output presented line by line as: 4.2 2.2457957 0.05037037 and so on OR at least have the results have something to show separation Solution 1: Everytime you want to terminate a line you can use the below : Alternatively, assuming you want a new line after you write the diff you can also do it like this : Solution 2: Wrap your FileWriter in a BufferedWriter, that way you can use the writer.newLine() method: An additional benefit is that the BufferedWriter is more efficient then using the FileWriter directly. The purpose of the Program is to add and save new ideas to a text file and that is why I don’t want to overwrite existing lines of text.

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Writing to a text file line by line

I am writing java code to read a from a text file, use the information read to calculate sum and difference and then write the results to a text file. My problem is that I have managed to write to the text file but the results are written as one continuous line. What I want is to have the results written line by line.

I have managed to write to the text file but the results are written as one continuous line.

The output shows the following as a single line:

What I expect is to have output presented line by line as: 4.2 2.2457957 0.05037037 and so on

OR at least have the results have something to show separation

Everytime you want to terminate a line you can use the below :

writer.write(System.getProperty("line.separator"));

Alternatively, assuming you want a new line after you write the diff you can also do it like this :

writer.write(diffr + System.getProperty("line.separator"));

Wrap your FileWriter in a BufferedWriter, that way you can use the writer.newLine() method:

try (BufferedWriter writer = new BufferedWriter(new FileWriter("results.text", true))) < writer.write(""); writer.newLine(); >catch(IOException ex)

An additional benefit is that the BufferedWriter is more efficient then using the FileWriter directly. In general, it is advisable to wrap a BufferedWriter around any Writer whose write() operations may be costly, such as FileWriters and OutputStreamWriters.

Note, in your example you are not managing the writer resource correctly as it will not be closed if an exception occurs, the close should be in a finally block. If using a recent Java version you can use the try-with-resources construct as shown in my example, this will close the writer automatically so you avoid having to write the finally block yourself.

Java FileWriter Class, package com.javatpoint; · import java.io.FileWriter; · public class FileWriterExample < · public static void main(String args[])< · try< · FileWriter fw=new

Java How to write to a text file

How to write data to a text file in Java. String permutation algorithm | All permutation of a Duration: 4:03

Files.write() : appending new lines in a text file

I’m using the code below to write into a text file

String content = "I Love Java"; Files.write(Paths.get(gg), (content + "\n").getBytes(UTF_8),StandardOpenOption.CREATE,StandardOpenOption.APPEND);

After 3 times of run, the text is saved into the the text as :

I Love JavaI Love JavaI Love Java

But, I want the text in the text file looks like:

I Love Java I Love Java I Love Java

You should avoid specific new line separators such as «\n» or «\r\n» that depends on the OS and favor the use of the System.lineSeparator() constant that applies at runtime the separator of the OS on which the JVM runs.

Write line by line to file using java.nio, Specify the StandardOpenOption.APPEND OpenOption as the last argument to Files.writeString . When this option is specified,

How to write text to a next empty line in text file in java

package ideat; import java.nio.file.Paths; import java.io.FileWriter; import java.util.Scanner; public class Paaohjelma < public static void main(String[] args) < try < Scanner tLuk = new Scanner(Paths.get("ideat.txt")); FileWriter tKirj = new FileWriter("ideat.txt"); for (String line = tLuk.nextLine(); line.isBlank(); tKirj.append("\n")) < tKirj.write("textHere"); >tKirj.close(); tLuk.close(); > catch (Exception e) < System.out.println(e); >> >

I created a loop that goes trough the txt-file until it finds an empty line to write, however this doesn’t work because when Scanner tries to read next line that is empty, java throws no next line exception. The purpose of the Program is to add and save new ideas to a text file and that is why I don’t want to overwrite existing lines of text.

Once you open a file you are reading in write mode, a file descriptor for reading is corrupted. It could be not corrupted, but once written something, it will be corrupted especially when what the descriptor will read overwritten.

So, you should take rewrite and replace approach:

 try < Scanner tLuk = new Scanner(Paths.get("ideat.txt")); FileWriter tKirj = new FileWriter("ideat.txt.tmp"); while (tLuk.hasNextLine()) < String line = tLuk.nextLine(); if (line.isBlank()) < tKirj.write("textHere"); >else < tKirj.write(line); >> tKirj.close(); tLuk.close(); > catch (Exception e)

Then, replace the file ideat.txt with ideat.txt.tmp .

Files.move( Paths.get("ideat.txt.tmp"), Paths.get("ideat.txt"), StandardCopyOption.REPLACE_EXISTING );

How to append text to an existing file in Java?, try < final Path path = Paths.get("path/to/filename.txt"); Files.write(path, Arrays.asList("New line to append

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How to Write to File Line by Line in Java with Examples

In this tutorial, we are going to explain the various ways of How to write to a file in Java with the illustrative examples.

Java write to file line by line is often needed in our day to day projects for creating files through java. There are various classes present in Java which can be used for write to file line by line.

Java write to file line by line using FileOutputStream class

FileOutputStream class is an output stream used for writing data to a File or FileDescriptor. FileOutputStream class is used to write streams of raw bytes such as image data. This class is good to use with bytes of data which cannot be represented as text such as excel document, PDF files, image files etc.

FileOutputStream class is part of the java.io package and it is a subclass of OutputStream class.

java write to file line by line

Example : Write to file line by line using FileOutputStream class

// Java Program for Write to file line by line using FileOutputStream class import java.io.File; import java.io.FileOutputStream; public class ExampleJavaFileWrite < public static void main(String[] args) < //Declaring reference of File class File file = null; //Declaring reference of FileOutputStream class FileOutputStream fileOutStream = null; String data = "TechBlogStation"; try < file = new File("D:/TBS/file.txt"); //Creating Object of FileOutputStream class fileOutStream = new FileOutputStream(file); //In case file does not exists, Create the file if (!file.exists()) < file.createNewFile(); >//fetching the bytes from data String byte[] b = data.getBytes(); //Writing to the file fileOutStream.write(b); //Flushing the stream fileOutStream.flush(); //Closing the stream fileOutStream.close(); System.out.println("File writing done."); > //Handing Exception catch (Exception e) < e.printStackTrace(); >finally < try < if (fileOutStream != null) < fileOutStream.close(); >> catch (Exception e) < e.printStackTrace(); >> > >

Java write to file line by line using FileWriter class

FileWriter class creates a writer which can be used to write to a file line by line. FileWriter class is part of the java.io package and it is a subclass of Writer class.

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FileWriter creation is not dependent on whether file exists or not . In case file does not exist, FileWriter class will create the file before opening it for output at the time of object creation. In the case , where you are attempting to open a read-only file , an IO Exception will be thrown.

java write to file line by line

Example : Write to file line by line using FileWriter class 

// Java Program for Write to file line by line using FileWriter class import java.io.File; import java.io.FileWriter; public class ExampleJavaFileWrite < public static void main(String[] args) < //Declaring reference of File class File file = null; //Declaring reference of FileWriter class FileWriter filewriter = null; String data = "TechBlogStation"; try < file = new File("D:/TBS/file.txt"); //Creating Object of FileWriter class filewriter = new FileWriter(file); //Writing to the file filewriter.write(data); //Closing the stream filewriter.close(); System.out.println("File writing done."); >//Handing Exception catch (Exception e) < e.printStackTrace(); >finally < try < if (filewriter != null) < filewriter.close(); >> catch (Exception e) < e.printStackTrace(); >> > >

Java write to file line by line using PrintWriter class

PrintWriter is a character oriented version of PrintStream class. Java’s PrintWriter object supports both the print() and println() method for all types even including object. If the calling argument is not a simple type, the printwriter will call the object’s toString() method and then print out the output.

PrintWriter class is part of the java.io package and it is a subclass of Writer class.

java write to file line by line

Example : Write to file line by line using PrintWriter class 

// Java Program for Write to file line by line using PrintWriter class import java.io.File; import java.io.PrintWriter; import java.io.FileWriter; public class ExampleJavaFileWrite < public static void main(String[] args) < //Declaring reference of File class File file = null; PrintWriter pw = null; try < //Creating object of PrintWriter class pw = new PrintWriter(new FileWriter("file.txt")); String data = "TechBlogStation"; //Writing to the file pw.write(data); //Closing the stream pw.close(); System.out.println("File writing done."); >//Handing Exception catch (Exception e) < e.printStackTrace(); >finally < try < if (pw != null) < pw.close(); >> catch (Exception e) < e.printStackTrace(); >> > >

OutputStreamWriter class

An OutputStreamWriter acts as a bridge from character streams to byte streams: Characters written to it will be encoded into bytes using a charset

OutputStreamWriter class is part of the java.io package and it is a subclass of Writer class.

java write to file line by line

OutputStreamWriter class Example: 

// Java Program for Write to file line by line using OutputStreamWriter class import java.io.File; import java.io.FileOutputStream; import java.io.OutputStreamWriter; public class ExampleJavaFileWrite < public static void main(String[] args) < //Declaring reference of File class File file = null; //Declaring reference of FileOutputStream class FileOutputStream fos = null; //Declaring reference of OutputStreamWriter class OutputStreamWriter osw = null; try < file = new File("result.txt"); //Creating object of FileOutputStream class fos = new FileOutputStream(file); //Creating object of OutputStreamWriter class osw = new OutputStreamWriter(fos); String data = "TechBlogStation"; //Writing to the file osw.write(data); //Closing the stream osw.close(); System.out.println("File writing done."); >//Handing Exception catch (Exception e) < e.printStackTrace(); >finally < try < if (osw != null) < osw.close(); >> catch (Exception e) < e.printStackTrace(); >> > >

Java write to file line by line using BufferedWriter

It will write text to a character-output stream, buffering characters to provide for the effective writing of single characters and strings.

A BufferedWriter is a Writer that adds a flush method which can be used to ensure that the data buffers are physically written to the actual output stream. BufferedWriter can increase the performance by reducing the number of times data is written to output stream.

BufferedWriter class is part of the java.io package and it is a subclass of Writer class.

java write to file line by line

Example : Write to file line by line using BufferedWriter

// Java Program for Write to file line by line using BufferedWriter class import java.io.File; import java.io.FileWriter; import java.io.BufferedWriter; public class ExampleJavaFileWrite < public static void main(String[] args) < //Declaring reference of File class File file = null; //Declaring reference of BufferedWriter class BufferedWriter bw = null; //Declaring reference of FileWriter class FileWriter fw = null; try < file = new File("result.txt"); //Creating object of FileWriter class fw = new FileWriter(file); //Creating object of BufferedWriter class bw = new BufferedWriter(fw); String data = "TechBlogStation"; //Writing to the file bw.write(data); //Closing the stream bw.close(); System.out.println("File writing done. "); >//Handing Exception catch (Exception e) < e.printStackTrace(); >finally < try < if (bw != null) < bw.close(); >> catch (Exception e) < e.printStackTrace(); >> > >

You can download the code for above examples from my github repository.

Conclusion

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We have learnt about various ways of writing file line by line in Java with the Examples. Any of the way can be used as per requirement to write to file. Now it will be easy to write a program for you using any of these ways.

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java write to file line by line

How do you write multiple lines in a text file in Java?

boolean append = true; String filename = "/path/to/file"; BufferedWriter writer = new BufferedWriter(new FileWriter(filename, append)); // OR: BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(filename, append))); writer. write(line1); writer. newLine(); writer.

Will FileWriter create a file?

FileWriter(String fileName) : Creates a FileWriter object using specified fileName. It throws an IOException if the named file exists but is a directory rather than a regular file or does not exist but cannot be created, or cannot be opened for any other reason.

How do you clear a text file in Java?

How do I change the first line of a file in Java?

replaceFirst(String regex, String replacement) (javadoc) or the RandomAccessFile (javadoc) can help you with this task. Open the file as RandomAccessFile. Read the 1st line into a string and then apply the change and then write the string back.

How do I change the content of a text file in Java?

open a temporary file in writing mode at the same time, and for each line, read it, modify if necessary, then write into the temporary file. At the end, delete the original and rename the temporary file. File file = new File(". your file. "); List lines = FileUtils.

How do you read a specific line in a text file in Java?

  1. import java. io. IOException;
  2. import java. nio. file. Files;
  3. import java. nio. file. Path;
  4. import java. nio. file. Paths;
  5. ​
  6. class FileRead
  7. public static void main( String args[] )
  8. int n = 1; // The line number.

How do you write to a file?

  1. write() : Inserts the string str1 in a single line in the text file. File_object.write(str1)
  2. writelines() : For a list of string elements, each string is inserted in the text file. Used to insert multiple strings at a single time.

How do you write Java code?

  1. Write the Java Source Code. .
  2. Save the File. .
  3. Open a Terminal Window. .
  4. The Java Compiler. .
  5. Change the Directory. .
  6. Compile Your Program. .
  7. Run the Program.

How do I create a Java file?

  1. Step 1: Make a File. Navigate to your My Documents folder in a file explorer. .
  2. Step 2: Write the Framework of Your Progam. .
  3. Step 3: Setup the "main" Method. .
  4. Step 4: Write Your Instruction. .
  5. Step 5: Save Your Program. .
  6. Step 6: Install the Java JDK. .
  7. Step 7: Copy the Path to the Java Tools. .
  8. Step 8: Open the Command Prompt.

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