This commit related to the article BAEL-6784 (#14900)

This commit aims to add a new test class to split Java String into Key-Value pairs

core-java-modules/core-java-string-conversions-3/src/test/java/com/baeldung/stringsplitkeyvalue/StringSplitKeyValueUnitTest.java

@@ -0,0 +1,80 @@
+package com.baeldung.stringsplitkeyvalue;
+
+import org.junit.jupiter.api.Test;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.StringTokenizer;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class StringSplitKeyValueUnitTest {
+
+@Test
+public void givenStringData_whenUsingTokenizer_thenTokenizeAndValidate() {
+    String data = "name=John age=30 city=NewYork";
+    StringTokenizer tokenizer = new StringTokenizer(data);
+
+    // Create a map to store key-value pairs
+    Map<String, String> keyValueMap = new HashMap<>();
+
+    while (tokenizer.hasMoreTokens()) {
+        String token = tokenizer.nextToken();
+        String[] keyValue = token.split("=");
+
+        if (keyValue.length == 2) {
+            String key = keyValue[0];
+            String value = keyValue[1];
+
+            // Store key-value pairs in the map
+            keyValueMap.put(key, value);
+        }
+    }
+
+    // Use assertions to validate the key-value pairs in the map
+    assertEquals("John", keyValueMap.get("name"));
+    assertEquals("30", keyValueMap.get("age"));
+    assertEquals("NewYork", keyValueMap.get("city"));
+}
+
+
+@Test
+public void givenDataWithPattern_whenUsingMatcher_thenPerformPatternMatching() {
+    String data = "name=John,age=30;city=NewYork";
+    Pattern pattern = Pattern.compile("\\b(\\w+)=(\\w+)\\b");
+    Matcher matcher = pattern.matcher(data);
+
+    // Create a map to store key-value pairs
+    Map<String, String> keyValueMap = new HashMap<>();
+
+    while (matcher.find()) {
+        String key = matcher.group(1);
+        String value = matcher.group(2);
+
+        // Store key-value pairs in the map
+        keyValueMap.put(key, value);
+    }
+
+    // Use assertions to validate the key-value pairs in the map
+    assertEquals("John", keyValueMap.get("name"));
+    assertEquals("30", keyValueMap.get("age"));
+    assertEquals("NewYork", keyValueMap.get("city"));
+}
+
+    @Test
+    public void givenStringData_whenUsingJavaMap_thenSplitAndValidate() {
+        String data = "name=John age=30 city=NewYork";
+        Map<String, String> keyValueMap = Arrays.stream(data.split(" "))
+                .map(kv -> kv.split("="))
+                .filter(kvArray -> kvArray.length == 2)
+                .collect(Collectors.toMap(kv -> kv[0], kv -> kv[1]));
+
+        assertEquals("John", keyValueMap.get("name"));
+        assertEquals("30", keyValueMap.get("age"));
+        assertEquals("NewYork", keyValueMap.get("city"));
+    }
+}