From 318c95f0c02a6a4a93fa42e951cf17799a84ff80 Mon Sep 17 00:00:00 2001
From: cdjole <djordje.cvijetic@gmail.com>
Date: Tue, 21 Aug 2018 13:41:26 +0200
Subject: [PATCH] String containing characters (#5026)

---
 .../StringContainingCharactersUnitTest.java   | 98 +++++++++++++++++++
 1 file changed, 98 insertions(+)
 create mode 100644 java-strings/src/test/java/com/baeldung/string/StringContainingCharactersUnitTest.java

diff --git a/java-strings/src/test/java/com/baeldung/string/StringContainingCharactersUnitTest.java b/java-strings/src/test/java/com/baeldung/string/StringContainingCharactersUnitTest.java
new file mode 100644
index 0000000000..75548f4d73
--- /dev/null
+++ b/java-strings/src/test/java/com/baeldung/string/StringContainingCharactersUnitTest.java
@@ -0,0 +1,98 @@
+package com.baeldung.string;
+
+import org.junit.Test;
+
+import java.util.regex.Pattern;
+
+import static junit.framework.TestCase.assertFalse;
+import static junit.framework.TestCase.assertTrue;
+
+public class StringContainingCharactersUnitTest {
+
+    private static final Pattern[] inputRegexes = new Pattern[4];
+
+    static {
+        inputRegexes[0] = Pattern.compile(".*[A-Z].*");
+        inputRegexes[1] = Pattern.compile(".*[a-z].*");
+        inputRegexes[2] = Pattern.compile(".*\\d.*");
+        inputRegexes[3] = Pattern.compile(".*[`~!@#$%^&*()\\-_=+\\\\|\\[{\\]};:'\",<.>/?].*");
+    }
+
+    private static boolean isMatchingRegex(String input) {
+        boolean inputMatches = true;
+        for (Pattern inputRegex : inputRegexes) {
+            if (!inputRegex
+              .matcher(input)
+              .matches()) {
+                inputMatches = false;
+            }
+        }
+        return inputMatches;
+    }
+
+    private static boolean checkString(String input) {
+        String specialChars = "~`!@#$%^&*()-_=+\\|[{]};:'\",<.>/?";
+        char currentCharacter;
+        boolean numberPresent = false;
+        boolean upperCasePresent = false;
+        boolean lowerCasePresent = false;
+        boolean specialCharacterPresent = false;
+
+        for (int i = 0; i < input.length(); i++) {
+            currentCharacter = input.charAt(i);
+            if (Character.isDigit(currentCharacter)) {
+                numberPresent = true;
+            } else if (Character.isUpperCase(currentCharacter)) {
+                upperCasePresent = true;
+            } else if (Character.isLowerCase(currentCharacter)) {
+                lowerCasePresent = true;
+            } else if (specialChars.contains(String.valueOf(currentCharacter))) {
+                specialCharacterPresent = true;
+            }
+        }
+
+        return numberPresent && upperCasePresent && lowerCasePresent && specialCharacterPresent;
+    }
+
+    @Test
+    public void givenRegexes_whenMatchingCorrectString_thenMatches() {
+        String validInput = "Ab3;";
+        assertTrue(isMatchingRegex(validInput));
+    }
+
+    @Test
+    public void givenRegexes_whenMatchingWrongStrings_thenNotMatching() {
+        String invalidInput = "Ab3";
+        assertFalse(isMatchingRegex(invalidInput));
+
+        invalidInput = "Ab;";
+        assertFalse(isMatchingRegex(invalidInput));
+
+        invalidInput = "A3;";
+        assertFalse(isMatchingRegex(invalidInput));
+
+        invalidInput = "b3;";
+        assertFalse(isMatchingRegex(invalidInput));
+    }
+
+    @Test
+    public void givenValidString_whenChecking_thenCorrect() {
+        String validInput = "Ab3;";
+        assertTrue(checkString(validInput));
+    }
+
+    @Test
+    public void givenInvalidStrings_whenChecking_thenNotCorrect() {
+        String invalidInput = "Ab3";
+        assertFalse(checkString(invalidInput));
+
+        invalidInput = "Ab;";
+        assertFalse(checkString(invalidInput));
+
+        invalidInput = "A3;";
+        assertFalse(checkString(invalidInput));
+
+        invalidInput = "b3;";
+        assertFalse(checkString(invalidInput));
+    }
+}