java text file code example

Example 1: writing to a file in java

import java.io.FileWriter;   // Import the FileWriter class
import java.io.IOException;  // Import the IOException class to handle errors

public class WriteToFile {
  public static void main(String[] args) {
    try {
      FileWriter myWriter = new FileWriter("filename.txt");
      myWriter.write("Files in Java might be tricky, but it is fun enough!");
      myWriter.close();
      System.out.println("Successfully wrote to the file.");
    } catch (IOException e) {
      System.out.println("An error occurred.");
      e.printStackTrace();
    }
  }
}

Example 2: java read file text

try(BufferedReader br = new BufferedReader(new FileReader("file.txt"))) {
    StringBuilder sb = new StringBuilder();
    String line = br.readLine();

    while (line != null) {
        sb.append(line);
        sb.append(System.lineSeparator());
        line = br.readLine();
    }
    String everything = sb.toString();
}

Example 3: java read text file

// how to read text file line by line using FileReader class
import java.io.FileReader;
import java.io.IOException;
public class JavaReadTextFileUsingFileReader
{
   public static void main(String[] args) throws IOException
   {
      FileReader fr = new FileReader("B:\demo.txt");
      int a;
      while((a = fr.read()) != -1)
      {
         System.out.print((char) a);
      }
      fr.close();
   }
}

Example 4: java read text file

// read text file as string in java
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
public class ReadTextFileAsStringJava
{
   public static void main(String[] args) throws Exception
   {
      String strInput = readFileString("B:\demo.txt");
      System.out.println(strInput);
   }
   public static String readFileString(String fileName) throws IOException
   {
      String strInput = "";
      strInput = new String(Files.readAllBytes(Paths.get(fileName)));
      return strInput;
   }
}