text: The
  Writer class of the
  java.io package is an abstract superclass that represents a stream of characters.
  Since
  Writer is an abstract class, it is not useful by itself. However, its subclasses can be used to write data.
  Subclasses of Writer
  In order to use the functionality of the
  Writer, we can use its subclasses. Some of them are:
  We will learn about all these subclasses in the next tutorial.
  Create a Writer
  In order to create a
  Writer, we must import the
  java.io.Writer package first. Once we import the package, here is how we can create the writer.
  // Creates a Writer Writer output = new FileWriter();
  Here, we have created a writer named output using the
  FileWriter class. It is because the
  Writer is an abstract class. Hence we cannot create an object of
  Writer.
  Note: We can also create writers from other subclasses of the
  Writer class.
  Methods of Writer
  The
  Writer class provides different methods that are implemented by its subclasses. Here are some of the methods:
  write(char[] array)- writes the characters from the specified array to the output stream
  write(String data)- writes the specified string to the writer
  append(char c)- inserts the specified character to the current writer
  flush()- forces to write all the data present in the writer to the corresponding destination
  close()- closes the writer
  Example: Writer Using FileWriter
  Here is how we can implement the
  Writer using the
  FileWriter class.
  import java.io.FileWriter; import java.io.Writer; public class Main { public static void main(String args[]) { String data = "This is the data in the output file"; try { // Creates a Writer using FileWriter Writer output = new FileWriter("output.txt"); // Writes string to the file output.write(data); // Closes the writer output.close(); } catch (Exception e) { e.getStackTrace(); } } }
  In the above example, we have created a writer using the
  FileWriter class. The writer is linked with the file output.txt.
  Writer output = new FileWriter("output.txt");
  To write data to the output.txt file, we have implemented these methods.
  output.write(); // To write data to the file output.close(); // To close the writer
  When we run the program, the output.txt file is filled with the following content.
  This is a line of text inside the file.
  To learn more, visit Java Writer (official Java documentation).