import java.io.IOException;

import java.io.InputStream;

import java.io.OutputStream;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.util.ArrayList;

import java.util.List;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

public class BinaryCodeInstrumenter {

private static final String INSTRUMENTATION_START = "/* INSTRUMENTATION_START */";

private static final String INSTRUMENTATION_END = "/* INSTRUMENTATION_END */";

private static final String LOG_START = "System.out.println(\"Task started\");";

private static final String LOG_END = "System.out.println(\"Task finished\");";

public static void instrument(Path filePath, String taskName) throws IOException {

try (InputStream inputStream = Files.newInputStream(filePath);

OutputStream outputStream = Files.newOutputStream(filePath)) {

byte[] fileBytes = inputStream.readAllBytes();

String originalCode = new String(fileBytes);

// Find the start and end of the code block

int start = originalCode.indexOf(INSTRUMENTATION_START);

int end = originalCode.indexOf(INSTRUMENTATION_END);

if (start == -1 || end == -1 || start >= end) {

System.err.println("Instrumentation markers not found in the file.");

return;

}

String beforeInstrumentation = originalCode.substring(0, start + INSTRUMENTATION_START.length());

String afterInstrumentation = originalCode.substring(end);

// Insert instrumentation code

String instrumentationCode = "\n" + LOG_START + "\n" + afterInstrumentation + "\n" + LOG_END + "\n";

//Write the modified content back

outputStream.write(beforeInstrumentation.getBytes());

outputStream.write(instrumentationCode.getBytes());

outputStream.write(afterInstrumentation.getBytes());

}

}

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

// Example usage:

String filePath = "example.class"; // Replace with your binary file path.

String taskName = "MyTask";

//Create a dummy file for testing

try (OutputStream out = Files.newOutputStream(Paths.get(filePath))) {

out.write("public class MyClass {\n" +

" public void myMethod() {\n" +

" System.out.println(\"Doing something...\");\n" +

" }\n" +

"}");

}

instrument(Paths.get(filePath), taskName);

System.out.println("Instrumentation completed.");

}

}