Add Json Parameter Converter using Gson BNN-366 #resolve (#329)

bennu-spring/src/main/java/org/fenixedu/bennu/spring/BennuSpringConfiguration.java

@@ -31,6 +31,8 @@
 
 import org.fenixedu.bennu.core.util.CoreConfiguration;
 import org.fenixedu.bennu.core.util.CoreConfiguration.ConfigurationProperties;
+import org.fenixedu.bennu.spring.converters.DomainObjectConverter;
+import org.fenixedu.bennu.spring.converters.JsonElementConverter;
 import org.fenixedu.bennu.spring.converters.LocalizedStringConverter;
 import org.fenixedu.bennu.spring.converters.UserFromUsernameConverter;
 import org.fenixedu.bennu.spring.portal.PortalHandlerInterceptor;
@@ -172,6 +174,7 @@ public ConversionService conversionService(GenericConversionService service) {
         service.addConverter(new DomainObjectConverter());
         service.addConverter(new LocalizedStringConverter());
         service.addConverter(new UserFromUsernameConverter());
+        service.addConverter(new JsonElementConverter());
         return service;
     }
 

bennu-spring/src/main/java/org/fenixedu/bennu/spring/DomainObjectConverter.java → bennu-spring/src/main/java/org/fenixedu/bennu/spring/converters/DomainObjectConverter.java

@@ -16,7 +16,7 @@
  * You should have received a copy of the GNU Lesser General Public License
  * along with Bennu Spring.  If not, see <http://www.gnu.org/licenses/>.
  */
-package org.fenixedu.bennu.spring;
+package org.fenixedu.bennu.spring.converters;
 
 import java.util.Collections;
 import java.util.Set;

bennu-spring/src/main/java/org/fenixedu/bennu/spring/converters/JsonElementConverter.java

@@ -0,0 +1,51 @@
+/**
+ * Copyright © 2018 Instituto Superior Técnico
+ *
+ * This file is part of Bennu Spring.
+ *
+ * Bennu Spring is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Bennu Spring is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Bennu Spring.  If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.fenixedu.bennu.spring.converters;
+
+import java.util.Collections;
+import java.util.Set;
+
+import com.google.gson.JsonElement;
+
+import com.google.gson.JsonParser;
+import org.springframework.core.convert.TypeDescriptor;
+import org.springframework.core.convert.converter.ConditionalGenericConverter;
+
+/**
+ * Converts a String to a JsonElement.
+ *
+ * @author Tiago Pinho ([email protected])
+ */
+public class JsonElementConverter implements ConditionalGenericConverter {
+
+    @Override
+    public boolean matches(TypeDescriptor sourceType, TypeDescriptor targetType) {
+        return String.class.equals(sourceType.getType()) && JsonElement.class.equals(targetType.getType());
+    }
+
+    @Override
+    public Set<ConvertiblePair> getConvertibleTypes(){
+        return Collections.singleton(new ConvertiblePair(String.class, JsonElement.class));
+    }
+
+    @Override
+    public JsonElement convert(Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {
+        return new JsonParser().parse((String) source);
+    }
+}