The task is done

src/main/java/com/epam/izh/rd/online/Main.java

@@ -1,4 +1,48 @@
 package com.epam.izh.rd.online;
 
+import com.epam.izh.rd.online.repository.SimpleFileRepository;
+import com.epam.izh.rd.online.service.SimpleBigNumbersService;
+import com.epam.izh.rd.online.service.SimpleDateService;
+import com.epam.izh.rd.online.service.SimpleRegExpService;
+import com.epam.izh.rd.online.service.SimpleTextService;
+
+import java.text.SimpleDateFormat;
+import java.time.LocalDate;
+import java.time.format.DateTimeFormatter;
+
 public class Main {
+
+    public static void main(String[] args) {
+//        SimpleFileRepository simpleFileRepository = new SimpleFileRepository();
+//        System.out.println(simpleFileRepository.countFilesInDirectory("c:/temp/java/java3"));
+//        System.out.println(simpleFileRepository.countDirsInDirectory("c:/temp/java/java3/"));
+//        simpleFileRepository.copyTXTFiles("c:/temp/java/java3/", "c:/temp/java/java4/");
+//        System.out.println(simpleFileRepository.createFile("c:/temp/java/java3/", "someNewFile.txt"));
+//        System.out.println(simpleFileRepository.readFileFromResources("readme.txt"));
+
+//        SimpleBigNumbersService simpleBigNumbersService = new SimpleBigNumbersService();
+//        System.out.println(simpleBigNumbersService.getPrecisionNumber(1, 3, 2));
+//        System.out.println(simpleBigNumbersService.getPrimaryNumber(100));
+
+//        SimpleDateService simpleDateService = new SimpleDateService();
+//        System.out.println(simpleDateService.parseDate(LocalDate.of(1974, 2, 9)));
+//        System.out.println(simpleDateService.parseString("1970-01-01 00:00"));
+//        System.out.println(simpleDateService.convertToCustomFormat(LocalDate.of(1974, 2, 9), DateTimeFormatter.ofPattern("yyyy-MM-dd")));
+//        System.out.println(simpleDateService.getNextLeapYear());
+//        System.out.println(simpleDateService.getSecondsInYear(2021));
+//        System.out.println(simpleDateService.getSecondsInYear(2020));
+
+//        SimpleRegExpService simpleRegExpService = new SimpleRegExpService();
+//        System.out.println(simpleRegExpService.maskSensitiveData());
+//        System.out.println(simpleRegExpService.replacePlaceholders(1, 2));
+
+//        SimpleTextService simpleTextService = new SimpleTextService();
+//        System.out.println(simpleTextService.removeString("Hello, hello, hello, how low?", ", he"));
+//        System.out.println(simpleTextService.isQuestionString("test!"));
+//        System.out.println(simpleTextService.concatenate(new String[]{"a", "b", "c"}));
+//        System.out.println(simpleTextService.toJumpCase("Load Up On Guns And Bring Your Friends"));
+//        System.out.println(simpleTextService.isPalindrome(""));
+    }
+
+
 }

src/main/java/com/epam/izh/rd/online/repository/SimpleFileRepository.java

@@ -1,5 +1,10 @@
 package com.epam.izh.rd.online.repository;
 
+import java.io.*;
+import java.nio.file.*;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.Arrays;
+
 public class SimpleFileRepository implements FileRepository {
 
     /**
@@ -10,6 +15,21 @@ public class SimpleFileRepository implements FileRepository {
      */
     @Override
     public long countFilesInDirectory(String path) {
+        if (!Paths.get(path).toFile().isDirectory()) return 0;
+
+        try {
+            final long[] count = {0};
+            Files.walkFileTree(Paths.get(path), new SimpleFileVisitor() {
+                @Override
+                public FileVisitResult visitFile(Object file, BasicFileAttributes attrs) throws IOException {
+                    count[0]++;
+                    return super.visitFile(path, attrs);
+                }
+            });
+            return count[0];
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
         return 0;
     }
 
@@ -21,6 +41,21 @@ public long countFilesInDirectory(String path) {
      */
     @Override
     public long countDirsInDirectory(String path) {
+        if (!Paths.get(path).toFile().isDirectory()) return 0;
+
+        try {
+            final long[] count = {0};
+            Files.walkFileTree(Paths.get(path), new SimpleFileVisitor() {
+                @Override
+                public FileVisitResult preVisitDirectory(Object dir, BasicFileAttributes attrs) throws IOException {
+                    count[0]++;
+                    return super.preVisitDirectory(dir, attrs);
+                }
+            });
+            return count[0];
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
         return 0;
     }
 
@@ -32,7 +67,22 @@ public long countDirsInDirectory(String path) {
      */
     @Override
     public void copyTXTFiles(String from, String to) {
-        return;
+        if (!Paths.get(from).toFile().isDirectory() || !Paths.get(to).toFile().isDirectory()) return;
+
+        final int[] countCopiedFiles = {0};
+        File[] files = Paths.get(from).toFile().listFiles();
+        if (files == null) return;
+        Arrays.stream(files)
+                .filter(file -> !file.isDirectory() && file.toString().toLowerCase().endsWith(".txt"))
+                .forEach(file -> {
+                    try {
+                        Files.copy(file.toPath(), Paths.get(to + "/" + file.getName()), StandardCopyOption.REPLACE_EXISTING);
+                        countCopiedFiles[0]++;
+                    } catch (IOException e) {
+                        e.printStackTrace();
+                    }
+                });
+        System.out.println(countCopiedFiles[0] + " files copied.");
     }
 
     /**
@@ -44,6 +94,19 @@ public void copyTXTFiles(String from, String to) {
      */
     @Override
     public boolean createFile(String path, String name) {
+        try {
+//            the dir is created additionally if it's missing
+            if (!Paths.get(path).toFile().exists()) {
+                boolean result = Paths.get(path).toFile().mkdir();
+                if (!result) {
+                    return false;
+                }
+            }
+
+            return Paths.get(path + "/" + name).toFile().createNewFile();
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
         return false;
     }
 
@@ -55,6 +118,15 @@ public boolean createFile(String path, String name) {
      */
     @Override
     public String readFileFromResources(String fileName) {
-        return null;
+        if (!fileName.toLowerCase().endsWith(".txt")) return "";
+
+        try ( BufferedReader reader = new BufferedReader(new FileReader("src/main/resources/" + fileName))) {
+            StringBuilder result = new StringBuilder();
+            reader.lines().forEach(line -> result.append("\n" + line));
+            return result.toString().substring(1);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        return "";
     }
 }

src/main/java/com/epam/izh/rd/online/service/SimpleBigNumbersService.java

@@ -13,7 +13,7 @@ public class SimpleBigNumbersService implements BigNumbersService {
      */
     @Override
     public BigDecimal getPrecisionNumber(int a, int b, int range) {
-        return null;
+        return new BigDecimal((double) a / (double) b).setScale(range, BigDecimal.ROUND_HALF_UP);
     }
 
     /**
@@ -24,6 +24,33 @@ public BigDecimal getPrecisionNumber(int a, int b, int range) {
      */
     @Override
     public BigInteger getPrimaryNumber(int range) {
-        return null;
+        if (range < 1) return null;
+        int checkNumber = 2;
+        int result = checkNumber;
+        int foundCo = 0;
+        while (foundCo <= range) {
+            if (isPrimary(checkNumber)) {
+                result = checkNumber;
+                foundCo++;
+            }
+            checkNumber++;
+        }
+        return new BigInteger(String.valueOf(result));
     }
+
+    /**
+     * Метод определяет, является ли заданное число простым.
+     * Простое число - число, которое делится только на 1 и на само себя.
+     *
+     * Например для числа 22 вернется false, а для числа 23 true.
+     */
+    public boolean isPrimary(int number) {
+        for (int i = 2; i < number; i++) {
+            if (number % i == 0) {
+                return false;
+            }
+        }
+        return true;
+    }
+
 }

src/main/java/com/epam/izh/rd/online/service/SimpleDateService.java

@@ -1,5 +1,6 @@
 package com.epam.izh.rd.online.service;
 
+import java.text.SimpleDateFormat;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
@@ -14,7 +15,7 @@ public class SimpleDateService implements DateService {
      */
     @Override
     public String parseDate(LocalDate localDate) {
-        return null;
+        return localDate.format(DateTimeFormatter.ofPattern("dd-MM-yyyy"));
     }
 
     /**
@@ -25,7 +26,7 @@ public String parseDate(LocalDate localDate) {
      */
     @Override
     public LocalDateTime parseString(String string) {
-        return null;
+        return LocalDateTime.parse(string, DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm"));
     }
 
     /**
@@ -37,7 +38,7 @@ public LocalDateTime parseString(String string) {
      */
     @Override
     public String convertToCustomFormat(LocalDate localDate, DateTimeFormatter formatter) {
-        return null;
+        return localDate.format(formatter);
     }
 
     /**
@@ -47,7 +48,10 @@ public String convertToCustomFormat(LocalDate localDate, DateTimeFormatter forma
      */
     @Override
     public long getNextLeapYear() {
-        return 0;
+        LocalDate localDate = LocalDate.now();
+        int year = localDate.getYear();
+        while (!LocalDate.of(year++,1,1).isLeapYear());
+        return --year;
     }
 
     /**
@@ -57,7 +61,8 @@ public long getNextLeapYear() {
      */
     @Override
     public long getSecondsInYear(int year) {
-        return 0;
+        int daySeconds = 3600 * 24;
+        return LocalDate.of(year,1,1).isLeapYear() ? 366 * daySeconds : 365 * daySeconds;
     }
 
 

src/main/java/com/epam/izh/rd/online/service/SimpleRegExpService.java

@@ -1,5 +1,13 @@
 package com.epam.izh.rd.online.service;
 
+import java.io.BufferedReader;
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.io.IOException;
+import java.nio.file.Paths;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
 public class SimpleRegExpService implements RegExpService {
 
     /**
@@ -11,6 +19,23 @@ public class SimpleRegExpService implements RegExpService {
      */
     @Override
     public String maskSensitiveData() {
+        try ( BufferedReader reader = new BufferedReader(new FileReader("src/main/resources/sensitive_data.txt"))) {
+            Pattern pattern = Pattern.compile("\\d{4} \\d{4} \\d{4} \\d{4}");
+            StringBuilder stringBuilder = new StringBuilder();
+            String line;
+            while ((line = reader.readLine()) != null) {
+                Matcher matcher = pattern.matcher(line);
+                while (matcher.find()) {
+                    String maskedReplacement = matcher.group().substring(0, 5) +
+                            "**** ****" + matcher.group().substring(14, 19);
+                    line = line.replace(matcher.group(), maskedReplacement);
+                }
+                stringBuilder.append("\n" + line);
+            }
+            return stringBuilder.toString().substring(1);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
         return null;
     }
 
@@ -22,6 +47,18 @@ public String maskSensitiveData() {
      */
     @Override
     public String replacePlaceholders(double paymentAmount, double balance) {
+        try ( BufferedReader reader = new BufferedReader(new FileReader("src/main/resources/sensitive_data.txt"))) {
+            StringBuilder stringBuilder = new StringBuilder();
+            String line;
+            while ((line = reader.readLine()) != null) {
+                line = line.replaceAll("\\$\\{payment_amount}",String.valueOf((int) paymentAmount));
+                line = line.replaceAll("\\$\\{balance}",String.valueOf((int) balance));
+                stringBuilder.append("\n" + line);
+            }
+            return stringBuilder.toString().substring(1);
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
         return null;
     }
 }

src/main/java/com/epam/izh/rd/online/service/SimpleTextService.java

@@ -1,5 +1,7 @@
 package com.epam.izh.rd.online.service;
 
+import java.util.Arrays;
+
 public class SimpleTextService implements TextService {
 
     /**
@@ -13,7 +15,7 @@ public class SimpleTextService implements TextService {
      */
     @Override
     public String removeString(String base, String remove) {
-        return null; //TODO
+        return base.replace(remove, "");
     }
 
     /**
@@ -24,7 +26,7 @@ public String removeString(String base, String remove) {
      */
     @Override
     public boolean isQuestionString(String text) {
-        return false; //TODO
+        return text.endsWith("?");
     }
 
     /**
@@ -35,7 +37,11 @@ public boolean isQuestionString(String text) {
      */
     @Override
     public String concatenate(String... elements) {
-        return null; //TODO
+        String result = "";
+        for (String string : elements) {
+            result += string;
+        }
+        return result.trim();
     }
 
     /**
@@ -47,7 +53,18 @@ public String concatenate(String... elements) {
      */
     @Override
     public String toJumpCase(String text) {
-        return null; //TODO
+        String result = "";
+        boolean isLowerCase = true;
+        for (int i = 0; i < text.length(); i++) {
+            if (isLowerCase) {
+                result += text.substring(i, i + 1).toLowerCase();
+                isLowerCase = false;
+            } else {
+                result += text.substring(i, i + 1).toUpperCase();
+                isLowerCase = true;
+            }
+        }
+        return result;
     }
 
     /**
@@ -59,6 +76,9 @@ public String toJumpCase(String text) {
      */
     @Override
     public boolean isPalindrome(String string) {
-       return false; //TODO
+        if (string == null) return false;
+        string = string.replace(" ", "");
+        if (string.length() == 0) return false;
+        return string.toLowerCase().equals(new StringBuilder(string.toLowerCase()).reverse().toString());
     }
 }