prog110

WIP

• Either extend your interface from CrudRepository<T, ID> (or more specific variant of it, if the classpath contains repositories for multiple types of data sources say JpaRepository<T, ID>, MongoRepository<T, ID>)
• (or) copy paste selective methods from CrudRepository/JpaRepository interface and annotate your interface with @RepositoryDefinition(domainClass = T.class, idClass = Id.class). With this your repository interface would be quite clean
• @EnableJpaRepositories (+ its persistence specific variants) at the @Configuration class level
• Expects the transaction manager to be named transactionManager & entityManagerFactory to be named entityManagerFactory by default. If not, we have to explicitly specify the actual names
• For all default method, you can find implementation in SimpleJpaRepository, which is internally annotated with @Repository (gives exception translation) & @Transactional(readOnly = true) for transactional guarantee

Queries

prog110

Kafka frequent commands

Assuming that the following environment variables are set:

• KAFKA_HOME where Kafka is installed on local machine (e.g. /opt/kafka)
• ZK_HOSTS identifies running zookeeper ensemble, e.g. ZK_HOSTS=192.168.0.99:2181
• KAFKA_BROKERS identifies running Kafka brokers, e.g. KAFKA_BROKERS=192.168.0.99:9092

Server

Start Zookepper and Kafka servers

prog110

  void saveAsImagePdfFromTextPdf() throws IOException {
    final Path originalPdfPath = Paths.get("<source pdf path>");
    final Path imagePdfPath = Paths.get("<destination pdf path>");
    try(PDDocument document = PDDocument.load(originalPdfPath.toFile()); PDDocument imageDoc = new PDDocument()) {
      PDFRenderer pdfRenderer = new PDFRenderer(document);
      for (int pageNum = 0; pageNum < document.getNumberOfPages(); ++pageNum) {
        final BufferedImage bufferedImage = pdfRenderer.renderImageWithDPI(pageNum, 300, ImageType.RGB);
        PDPage page = new PDPage(new PDRectangle(bufferedImage.getWidth(), bufferedImage.getHeight()));
 imageDoc.addPage(page);

prog110

import com.lowagie.text.Document;
import com.lowagie.text.pdf.PdfCopy;
import com.lowagie.text.pdf.PdfImportedPage;
import com.lowagie.text.pdf.PdfReader;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.file.Files;
import java.nio.file.Path;

prog110

  public static void zip(Path sourceDirPath, Path zipFilePath) throws IOException {
    //@formatter:off
    createFile(zipFilePath, DEFAULT_FILE_ATTRS);
    try (ZipOutputStream zos = new ZipOutputStream(newOutputStream(zipFilePath)); Stream<Path> paths = Files.walk(sourceDirPath)) {
      paths.filter(path -> !Files.isDirectory(path))
          .forEach(path -> {
            ZipEntry zipEntry = new ZipEntry(sourceDirPath.relativize(path).toString());
            try {
              zos.putNextEntry(zipEntry);
              Files.copy(path, zos);

prog110

public static void deleteDirRecursively(Path pathToDel) throws IOException {
  Files.walk(pathToDel)
      .sorted(reverseOrder()) // dir would be listed before the files inside. So, we delete the files in the right order
      .forEach(path -> run(() -> delete(path)));
}

prog110

public static int getNumOfDigits(int number) {
  int numOfDigits = 0;
  int remainder = number;
  do {
    numOfDigits++;
    remainder = remainder / 10;
  } while (remainder > 0);
  return numOfDigits;
}

prog110

public static String base64Encode(Path filePath) {
  String base64EncodeFileConetnt = "";
  try (InputStream fileStream = newInputStream(filePath)) {
    // Reading a Image file from file system
    byte[] fileData = new byte[(int) Files.size(filePath)];
    //noinspection ResultOfMethodCallIgnored
    fileStream.read(fileData);
    base64EncodeFileConetnt = Base64.getEncoder().encodeToString(fileData);
  } catch (FileNotFoundException e) {
    System.out.println("File not found" + e);

prog110

// ==UserScript==
// @name         wikipedia
// @namespace    http://tampermonkey.net/
// @version      0.1
// @author       You
// @match        https://*.wikipedia.org/wiki/*
// @match        https://*.wikiquote.org/wiki/*
// @match        https://*.wiktionary.org/wiki/*
// @grant        none
// ==/UserScript==

prog110

// ==UserScript==
// @name         Merriam Webster -> Lexico linker
// @namespace    http://tampermonkey.net/
// @version      0.1
// @author       You
// @match        https://www.merriam-webster.com/dictionary/*
// @grant        none
// ==/UserScript==

(function() {