FileReader and FileWriter in Java

The FileReader and FileWriter classes in Java are used for reading and writing text files. This tutorial provides a step-by-step guide with examples.

Step 1: Writing to a File using FileWriter

The FileWriter class writes text to a file. Below is an example:

    import java.io.FileWriter;
    import java.io.IOException;
    
    public class FileWriterExample {
        public static void main(String[] args) {
            try {
                FileWriter writer = new FileWriter("fileWriterOutput.txt");
                writer.write("This is the first line of text.\n");
                writer.write("FileWriter makes writing to files easy!\n");
                writer.close();
                System.out.println("File written successfully using FileWriter.");
            } catch (IOException e) {
                System.out.println("An error occurred: " + e.getMessage());
            }
        }
    }

Step 2: Reading from a File using FileReader

The FileReader class reads text from a file. Below is an example:

    import java.io.FileReader;
    import java.io.IOException;
    
    public class FileReaderExample {
        public static void main(String[] args) {
            try {
                FileReader reader = new FileReader("fileWriterOutput.txt");
                int character;
                while ((character = reader.read()) != -1) {
                    System.out.print((char) character);
                }
                reader.close();
            } catch (IOException e) {
                System.out.println("An error occurred: " + e.getMessage());
            }
        }
    }

Step 3: Combining FileReader and FileWriter

Here is an example where text is read from one file using FileReader and written to another file using FileWriter:

    import java.io.FileReader;
    import java.io.FileWriter;
    import java.io.IOException;
    
    public class FileReaderWriterExample {
        public static void main(String[] args) {
            try {
                FileReader reader = new FileReader("sourceFile.txt");
                FileWriter writer = new FileWriter("destinationFile.txt");
                int character;
                while ((character = reader.read()) != -1) {
                    writer.write(character);
                }
                reader.close();
                writer.close();
                System.out.println("File copied successfully using FileReader and FileWriter.");
            } catch (IOException e) {
                System.out.println("An error occurred: " + e.getMessage());
            }
        }
    }

Summary

In this tutorial, you learned:

  • How to write to a file using FileWriter
  • How to read from a file using FileReader
  • How to combine FileReader and FileWriter for file manipulation

The FileReader and FileWriter classes are simple and effective for handling text files in Java.




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