import java.io.IOException;

import java.io.PrintWriter;

import java.net.URL;

import java.net.URLConnection;

public class HtmlInstrumenter {

public static void instrumentHtml(String urlString) throws IOException {

URL url = new URL(urlString);

URLConnection connection = url.openConnection();

String htmlContent = connection.getInputStream().readString(connection.getContentLength());

// Inject script tag at the beginning of the HTML

String instrumentedHtml = "<script>function logError(message) { console.error('HTML Instrumentation Error: ' + message); } </script>\n" + htmlContent;

// Output the instrumented HTML to a file (or back to the user)

try (PrintWriter writer = new PrintWriter(System.out)) {

writer.println(instrumentedHtml);

}

}

public static void main(String[] args) throws IOException {

if (args.length != 1) {

System.out.println("Usage: java HtmlInstrumenter <url>");

return;

}

String url = args[0];

instrumentHtml(url);

}

}