BAEL-2480 Java Map to String conversion (#6075)

* BAEL-2480 Java Map to String conversion

* BAEL-2480 Java Map to String conversion

* BAEL-2480 Java Map to String conversion

* BAEL-2480 Java Map to String conversion

java-collections-maps/src/main/java/com/baeldung/convert/MapToString.java

@@ -0,0 +1,34 @@
+package com.baeldung.convert;
+
+import com.google.common.base.Joiner;
+import org.apache.commons.lang3.StringUtils;
+
+import java.util.Map;
+import java.util.stream.Collectors;
+
+public class MapToString {
+
+    public static String convertWithIteration(Map<Integer, ?> map) {
+        StringBuilder mapAsString = new StringBuilder("{");
+        for (Integer key : map.keySet()) {
+            mapAsString.append(key + "=" + map.get(key) + ", ");
+        }
+        mapAsString.delete(mapAsString.length()-2, mapAsString.length()).append("}");
+        return mapAsString.toString();
+    }
+
+    public static String convertWithStream(Map<Integer, ?> map) {
+        String mapAsString = map.keySet().stream()
+                .map(key -> key + "=" + map.get(key))
+                .collect(Collectors.joining(", ", "{", "}"));
+        return mapAsString;
+    }
+
+    public static String convertWithGuava(Map<Integer, ?> map) {
+        return Joiner.on(",").withKeyValueSeparator("=").join(map);
+    }
+
+    public static String convertWithApache(Map map) {
+        return StringUtils.join(map);
+    }
+}

java-collections-maps/src/main/java/com/baeldung/convert/StringToMap.java

@@ -0,0 +1,21 @@
+package com.baeldung.convert;
+
+import com.google.common.base.Splitter;
+
+import java.util.Arrays;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+public class StringToMap {
+
+    public static Map<String, String> convertWithStream(String mapAsString) {
+        Map<String, String> map = Arrays.stream(mapAsString.split(","))
+                .map(entry -> entry.split("="))
+                .collect(Collectors.toMap(entry -> entry[0], entry -> entry[1]));
+        return map;
+    }
+
+    public static Map<String, String> convertWithGuava(String mapAsString) {
+        return Splitter.on(',').withKeyValueSeparator('=').split(mapAsString);
+    }
+}