If you work with FileOutputStream methods, each time you write your file through this methods you've been lost your old data. Is it possible to write file without losing your old data via FileOutputStream?
Use the constructor that takes a File and a boolean
FileOutputStream(File file, boolean append)
and set the boolean to true. That way, the data you write will be appended to the end of the file, rather than overwriting what was already there.
Use the constructor for appending material to the file:
FileOutputStream(File file, boolean append)
Creates a file output stream to write to the file represented by the specified File object.
So to append to a file say "abc.txt" use
FileOutputStream fos=new FileOutputStream(new File("abc.txt"),true);
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If you work with FileOutputStream methods, each time you write your file through this methods you've been lost your old data. Is it possible to write file without losing your old data via FileOutputStream?
Use the constructor that takes a File and a boolean
FileOutputStream(File file, boolean append)
and set the boolean to true. That way, the data you write will be appended to the end of the file, rather than overwriting what was already there.
Use the constructor for appending material to the file:
FileOutputStream(File file, boolean append)
Creates a file output stream to write to the file represented by the specified File object.
So to append to a file say "abc.txt" use
FileOutputStream fos=new FileOutputStream(new File("abc.txt"),true);
If you work with FileOutputStream methods, each time you write your file through this methods you've been lost your old data. Is it possible to write file without losing your old data via FileOutputStream?
Use the constructor that takes a File and a boolean
FileOutputStream(File file, boolean append)
and set the boolean to true. That way, the data you write will be appended to the end of the file, rather than overwriting what was already there.
Use the constructor for appending material to the file:
FileOutputStream(File file, boolean append)
Creates a file output stream to write to the file represented by the specified File object.
So to append to a file say "abc.txt" use
FileOutputStream fos=new FileOutputStream(new File("abc.txt"),true);
If you work with FileOutputStream methods, each time you write your file through this methods you've been lost your old data. Is it possible to write file without losing your old data via FileOutputStream?
Use the constructor that takes a File and a boolean
FileOutputStream(File file, boolean append)
and set the boolean to true. That way, the data you write will be appended to the end of the file, rather than overwriting what was already there.
Use the constructor for appending material to the file:
FileOutputStream(File file, boolean append)
Creates a file output stream to write to the file represented by the specified File object.
So to append to a file say "abc.txt" use
FileOutputStream fos=new FileOutputStream(new File("abc.txt"),true);
I am generating random numbers and putting that in a file and from that file I m reading the values. Now while reading it is reading all the values which has been put to the file again rather than reading the last added value. So what I want is to delete the contents of the file before writing any random number to it again so that when it reads from it, it will only read the last added value.
If you're doing this all at the same time via RandomAccessFile, just call RandomAccessFile.setLength(0).
If you're doing it via a FileOutputStream or FileWriter, just create a new one without the append parameter, or with that parameter set to `false.
Write an empty string into the file like below
PrintWriter writer = new PrintWriter(file);
writer.print("");
writer.close();
How can i prevent prinwriter in java from overwriting what's inside of that particular file?
Ex. I have a student.txt file. I already have few names there. After running and modifying this How do I create a file and write to it in Java? whats inside of that file will be overwritten. I just want to add it to the new line.
Also, how can i possibly perform search?
PrintWriter out = new PrintWriter(new FileWriter("student.txt", true));
The true is the append parameter - which indicates whether the FileWriter should append to the file. If it was false it would overwrite existing data in the file.
What do you mean by "how can i possibly perform search"?