* Copyright (c) 2013, 2019, Oracle and/or its affiliates. All rights reserved.

import java.io.ByteArrayOutputStream;

import java.io.InputStream;

import java.util.jar.JarFile;

import java.util.jar.Manifest;

import java.util.zip.ZipFile;

import static java.nio.charset.StandardCharsets.UTF_8;

    static void printNonPrintableCharactersEscaped(byte[] manifest)

            throws IOException {

        // keep byte sequences encoding multi-byte UTF-8 encoded and composite

        // characters together as much as possible before decoding into a String

        ByteArrayOutputStream lineBuf = new ByteArrayOutputStream();

        for (int i = 0; i < manifest.length; i++) {

            switch (manifest[i]) {

            case '\t':

                lineBuf.write("\\t".getBytes(UTF_8));

                break;

            case '\r':

                lineBuf.write("\\r".getBytes(UTF_8));

                if (i + 1 >= manifest.length || manifest[i + 1] != '\n') {

                    System.out.println(lineBuf.toString(UTF_8));

                    lineBuf.reset();

                }

                break;

            case '\n':

                lineBuf.write("\\n".getBytes(UTF_8));

                System.out.println(lineBuf.toString(UTF_8));

                lineBuf.reset();

                break;

            default:

                lineBuf.write(manifest[i]);

            }

        }

        if (lineBuf.size() > 0) {

            System.out.println(lineBuf.toString(UTF_8));

        }

    }

    static void echoManifest(byte[] manifest, String msg) throws IOException {

        System.out.println("-".repeat(72));

        System.out.println(msg);

        System.out.println("-".repeat(72));

        printNonPrintableCharactersEscaped(manifest);

        System.out.println("-".repeat(72));

    }

    static byte[] readJarManifestBytes(String jarFilename) throws IOException {

        return readJarEntryBytes(jarFilename, JarFile.MANIFEST_NAME);

    }

    static byte[] readJarEntryBytes(String jarFilename, String jarEntryname)

            throws IOException {

        try (

            ZipFile jar = new ZipFile(jarFilename);

            InputStream is = jar.getInputStream(jar.getEntry(jarEntryname));

        ) {

            return is.readAllBytes();

        }

    }

    static String escapeStringWithNumbers(String lineBreak) {

        String escaped = "";

        byte[] bytes = lineBreak.getBytes(UTF_8);

        for (int i = 0; i < bytes.length; i++) {

            escaped += bytes[i];

        }

        return escaped;

    }