Reading a File from End to Start Using BufferReader in Java
Problem:
You need to read a file from the end to the beginning, in reverse order, using a BufferedReader.
Solution:
The standard BufferedReader class does not support reading a file in reverse order. However, you can utilize the RandomAccessFile class to achieve this. Here's an example of how you can do it:
<code class="java">import java.io.BufferedReader; import java.io.File; import java.io.FileNotFoundException; import java.io.FileReader; import java.io.IOException; import java.io.RandomAccessFile; public class ReverseFileReader { public static void main(String[] args) { // Create a RandomAccessFile to access the file RandomAccessFile file = null; BufferedReader reader = null; try { file = new RandomAccessFile("filepath.txt", "r"); // Get the file size long fileSize = file.length(); // Start reading from the end of the file file.seek(fileSize - 1); // Initialize a BufferedReader to read from the RandomAccessFile reader = new BufferedReader(new FileReader(file.getFD())); // Read the file line by line in reverse order while ((file.getFilePointer()) > 0) { // Get the current line String line = reader.readLine(); // Adjust the file pointer to the beginning of the previous line file.seek(file.getFilePointer() - line.length() - 1); // Print the line System.out.println(line); } } catch (FileNotFoundException e) { System.out.println("File not found."); } catch (IOException e) { System.out.println("Error reading file."); } finally { // Close the file and the reader try { if (file != null) file.close(); if (reader != null) reader.close(); } catch (IOException e) {} } } }</code>
In this example, the RandomAccessFile is used to read the file from the end by starting at the end of the file and adjusting the file pointer backward for each line read. As each line is read, its starting position is adjusted in the file until the beginning of the file is reached, allowing you to read the file in reverse order.
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