Offer a threadsafe, easy to use shorthand for JSON-B fromJson(). IQSS…

…#6810

src/main/java/edu/harvard/iq/dataverse/util/json/JsonUtil.java

@@ -5,12 +5,15 @@
 import java.util.Collections;
 import java.util.logging.Logger;
 import javax.json.*;
+import javax.json.bind.Jsonb;
+import javax.json.bind.JsonbBuilder;
 import javax.json.stream.JsonGenerator;
 
 public class JsonUtil {
 
     private static final Logger logger = Logger.getLogger(JsonUtil.class.getCanonicalName());
     private static JsonWriterFactory jsonWriterFactory = Json.createWriterFactory(Collections.singletonMap(JsonGenerator.PRETTY_PRINTING, true));
+    private static Jsonb jsonb = JsonbBuilder.create();
 
     /**
      * Make an attempt at pretty printing a String but will return the original
@@ -41,5 +44,36 @@ public static String prettyPrint(JsonStructure jsonStructure) {
         }
         return stringWriter.toString();
     }
+
+    /**
+     * Get a primitive data value from a JSON Value or throw a {@link IllegalStateException}.
+     * Null-safe, returning empty string.
+     */
+    public static String getPrimitiveAsString(JsonValue value) {
+        if (value == null || value.getValueType().equals(JsonValue.ValueType.NULL)) {
+            return "";
+        } else if (
+            ! value.getValueType().equals(JsonValue.ValueType.ARRAY) &&
+            ! value.getValueType().equals(JsonValue.ValueType.OBJECT) )
+        {
+            return value.toString();
+        } else {
+            throw new IllegalStateException("Not a primitive: "+value.toString());
+        }
+    }
+
+    /**
+     * Offering a shorthand for JSON-B binding use
+     */
+    public static <T> T fromJson(String json, Class<T> toClass) {
+        return jsonb.fromJson(json, toClass);
+    }
+
+    /**
+     * Offer a shorthand for JSON-B binding use
+     */
+    public static <T> T fromJson(JsonValue json, Class<T> toClass) {
+        return fromJson(json.toString(), toClass);
+    }
 
 }