Added KeyDeserializer class and test code (#1523)

* Solr w Apache SolrJ

* Solr w Apache SolrJ

* updated test names and moved add to @before method

* create apache-solrj module, moved code from spring-data-solr

* More examples for indexing,delete,and query for solrj

* More examples for indexing,delete,and query for solrj

* Jackson Map Serialize/Deserialize

* Jackson Map Serialize/Deserialize

* Jackson version update

* keydeserializer code added

* keydeserializer code added

jackson/src/main/java/com/baeldung/jackson/entities/ClassWithAMap.java

@@ -0,0 +1,24 @@
+package com.baeldung.jackson.entities;
+
+import java.util.Map;
+
+import com.baeldung.jackson.serialization.MyPairDeserializer;
+import com.fasterxml.jackson.annotation.JsonCreator;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
+
+public class ClassWithAMap {
+
+	@JsonProperty("map")
+	@JsonDeserialize(keyUsing = MyPairDeserializer.class)
+	private final Map<MyPair, String> map;
+
+	@JsonCreator
+	public ClassWithAMap(Map<MyPair, String> map) {
+		this.map = map;
+	}
+
+	public Map<MyPair, String> getMap() {
+		return map;
+	}
+}

jackson/src/main/java/com/baeldung/jackson/serialization/MyPairDeserializer.java

@@ -0,0 +1,18 @@
+package com.baeldung.jackson.serialization;
+
+import java.io.IOException;
+
+import com.baeldung.jackson.entities.MyPair;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.DeserializationContext;
+import com.fasterxml.jackson.databind.KeyDeserializer;
+
+public class MyPairDeserializer extends KeyDeserializer {
+
+	@Override
+	public MyPair deserializeKey(String key, DeserializationContext ctxt)
+			throws IOException, JsonProcessingException {
+
+		return new MyPair(key);
+	}
+}