Step by Step solution about How to resolve the algorithm Strip block comments step by step in the Java programming language

Java Program to Strip Block Comments from a File

This Java program allows you to remove block comments from a source code file. Block comments are typically delimited by /* and */ in many programming languages.

Program Overview:

The program takes three arguments:

• BeginToken: The start delimiter for block comments (e.g., /*).
• EndToken: The end delimiter for block comments (e.g., */).
• FileToProcess: The name of the file from which to remove block comments.

Implementation Details:

• FileReader: The FileReader class is used to read the input file.
• StringBuilder: The StringBuilder class is used to build the modified string with comments removed.
• stripComments Method: This method uses a while loop to find and remove block comments from the input string. It iterates through the input string and searches for the BeginToken. If found, it searches for the corresponding EndToken and replaces the entire block with an empty string.
• main Method: The main method takes the input arguments, calls the readFile method to read the file contents, and calls the stripComments method to remove block comments. The modified string is then printed to the console.

Flow of Execution:

1. Read the input file using readFile.
2. Initialize an empty StringBuilder.
3. Use the stripComments method to remove block comments from the input file contents.
4. Append the modified string to the StringBuilder.
5. Print the modified string to the console.

import java.io.*;

public class StripBlockComments{
    public static String readFile(String filename) {
	BufferedReader reader = new BufferedReader(new FileReader(filename));
	try {
	    StringBuilder fileContents = new StringBuilder();
	    char[] buffer = new char[4096];
	    while (reader.read(buffer, 0, 4096) > 0) {
		fileContents.append(buffer);
	    }
	    return fileContents.toString();
	} finally {
	    reader.close();
	}
    }

    public static String stripComments(String beginToken, String endToken,
				       String input) {
	StringBuilder output = new StringBuilder();
	while (true) {
	    int begin = input.indexOf(beginToken);
	    int end = input.indexOf(endToken, begin+beginToken.length());
	    if (begin == -1 || end == -1) {
		output.append(input);
		return output.toString();
	    }
	    output.append(input.substring(0, begin));
	    input = input.substring(end + endToken.length());
	}
    }

    public static void main(String[] args) {
	if (args.length < 3) {
	    System.out.println("Usage: BeginToken EndToken FileToProcess");
	    System.exit(1);
	}

	String begin = args[0];
	String end = args[1];
	String input = args[2];

	try {
	    System.out.println(stripComments(begin, end, readFile(input)));
	} catch (Exception e) {
	    e.printStackTrace();
	    System.exit(1);
	}
    }
}