Combining HTML files containing tables and graphs in java

To merge HTML files in Java and combine their tables and graphs, you can use the FileWriter class to write the contents of each HTML file to a new file, one after the other. In the process, you can use a regular expression to search for <table> and <img> tags in the HTML files and replace them with the contents of the tables and images. You can also check if the HTML files and table/image files exist before trying to read them. Here is an example of how to do this:

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class HtmlMerger {

  public static void main(String[] args) {
    // The HTML files to merge
    String[] htmlFiles = {"file1.html", "file2.html", "file3.html"};

    // The output file
    File outputFile = new File("merged.html");

    try {
      FileWriter writer = new FileWriter(outputFile);

      // Write the contents of each HTML file to the output file
      for (String file : htmlFiles) {
        File htmlFile = new File(file);

        // Check if the HTML file exists
        if (htmlFile.exists()) {
          String html = htmlFile.getContent();

          // Find all <table> and <img> tags in the HTML file
          Pattern pattern = Pattern.compile("<(table|img)[^>]+src\\s*=\\s*['\"]([^'\"]+)['\"][^>]*>");
          Matcher matcher = pattern.matcher(html);

          // Replace the <table> and <img> tags with the contents of the tables and images
          while (matcher.find()) {
            String tagName = matcher.group(1); // The name of the tag (table or img)
            String src = matcher.group(2);     // The src attribute of the tag
            File srcFile = new File(src);     // The table or image file

            // Check if the table or image file exists
            if (srcFile.exists()) {
              String content = srcFile.getContent(); // The contents of the file
              html = html.replace(matcher.group(), content); // Replace the tag with the file
            }
          }

          // Write the modified HTML to the output file
          writer.write(html);
        }
      }

      // Close the writer to save the output file
      writer.close();

    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}

In this example, we define an array of HTML files to merge, and a File object representing the output file. We then create a FileWriter object that writes to the output file. In a loop, we read the contents of each HTML file and check if it exists. If it does, we search for <table> and <img> tags using a regular expression. For each tag, we check if the corresponding table or image file exists, and if it does, we replace the tag with the file's contents. Finally, we write the modified HTML to the output file and close the FileWriter to save the output