Minor code improvements.

README.md

@@ -4,8 +4,7 @@
 
 Java Binding for JSON-LD (JB4JSON-LD) is a simple library for serialization of Java objects into JSON-LD and vice versa.
 
-Note that this is the core, abstract implementation. For actual usage, a binding like 
-[https://github.com/kbss-cvut/jb4jsonld-jackson](https://github.com/kbss-cvut/jb4jsonld-jackson)
+Note that this is the core, abstract implementation. For actual usage, a binding like [https://github.com/kbss-cvut/jb4jsonld-jackson](https://github.com/kbss-cvut/jb4jsonld-jackson)
 has to be used.
 
 More information can be found at [https://kbss.felk.cvut.cz/web/kbss/jb4json-ld](https://kbss.felk.cvut.cz/web/kbss/jb4json-ld).

src/main/java/cz/cvut/kbss/jsonld/common/BeanClassProcessor.java

@@ -1,11 +1,11 @@
 /**
  * Copyright (C) 2020 Czech Technical University in Prague
- *
+ * <p>
  * This program is free software: you can redistribute it and/or modify it under
  * the terms of the GNU General Public License as published by the Free Software
  * Foundation, either version 3 of the License, or (at your option) any
  * later version.
- *
+ * <p>
  * This program 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 General Public License for more
@@ -18,6 +18,7 @@
 import cz.cvut.kbss.jsonld.exception.TargetTypeException;
 
 import java.lang.reflect.Field;
+import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.ParameterizedType;
 import java.lang.reflect.Type;
 import java.net.URI;
@@ -77,8 +78,8 @@ public static void setFieldValue(Field field, Object instance, Object value) {
      */
     public static <T> T createInstance(Class<T> cls) {
         try {
-            return cls.newInstance();
-        } catch (InstantiationException | IllegalAccessException e) {
+            return cls.getDeclaredConstructor().newInstance();
+        } catch (NoSuchMethodException | InstantiationException | InvocationTargetException | IllegalAccessException e) {
             throw new BeanProcessingException("Class " + cls + " is missing a public no-arg constructor.", e);
         }
     }
@@ -210,7 +211,7 @@ public static Class<?> getMapGenericValueType(Field field) {
                 final Type actualType = valueType.getActualTypeArguments()[0];
                 if (Class.class.isAssignableFrom(actualType.getClass())) {
                     // For Map<?, Collection<String>>
-                    return Class.class.cast(actualType);
+                    return (Class) actualType;
                 }
                 // For Map<?, Collection<?>>
                 return null;

src/test/java/cz/cvut/kbss/jsonld/common/JsonLdPropertyAccessResolverTest.java

@@ -28,7 +28,7 @@
 
 class JsonLdPropertyAccessResolverTest {
 
-    private JsonLdPropertyAccessResolver sut = new JsonLdPropertyAccessResolver();
+    private final JsonLdPropertyAccessResolver sut = new JsonLdPropertyAccessResolver();
 
     @ParameterizedTest
     @CsvSource({

src/test/java/cz/cvut/kbss/jsonld/deserialization/NodeReferenceContextTest.java

@@ -39,7 +39,7 @@ class NodeReferenceContextTest {
 
     @BeforeEach
     void setUp() {
-        MockitoAnnotations.initMocks(this);
+        MockitoAnnotations.openMocks(this);
     }
 
     @Test

src/test/java/cz/cvut/kbss/jsonld/serialization/PropertiesFieldSerializerTest.java

@@ -30,7 +30,7 @@ class PropertiesFieldSerializerTest {
 
     private Field field;
 
-    private FieldSerializer serializer = new PropertiesFieldSerializer();
+    private final FieldSerializer serializer = new PropertiesFieldSerializer();
 
     @BeforeEach
     void setUp() throws Exception {
@@ -143,4 +143,4 @@ void serializeFieldSerializesTypedPropertiesToCorrectTargetTypes() {
             }
         }
     }
-}
+}

src/test/java/cz/cvut/kbss/jsonld/serialization/model/AbstractNodeTest.java

@@ -24,6 +24,6 @@ public abstract class AbstractNodeTest {
     JsonGenerator serializerMock;
 
     public void setUp() {
-        MockitoAnnotations.initMocks(this);
+        MockitoAnnotations.openMocks(this);
     }
 }

src/test/java/cz/cvut/kbss/jsonld/serialization/traversal/ObjectGraphTraverserTest.java

@@ -49,7 +49,7 @@ class ObjectGraphTraverserTest {
 
     @BeforeEach
     void setUp() {
-        MockitoAnnotations.initMocks(this);
+        MockitoAnnotations.openMocks(this);
         this.traverser = new ObjectGraphTraverser();
         traverser.addVisitor(visitor);
     }

src/test/java/cz/cvut/kbss/jsonld/serialization/util/BufferedJsonGenerator.java

@@ -20,7 +20,7 @@
 
 public class BufferedJsonGenerator implements JsonGenerator {
 
-    private StringBuilder buffer = new StringBuilder();
+    private final StringBuilder buffer = new StringBuilder();
 
     private boolean firstElement = true;
     private boolean firstAttribute = true;