Fixed some Sonar issues

.gitignore

@@ -1,3 +1,5 @@
 bin/
 target/
 .history/
+*.iml
+.idea/

com.eclipsesource.json/src/main/java/com/eclipsesource/json/Json.java

@@ -53,6 +53,12 @@
  */
 public final class Json {
 
+  // String constants
+  private static final String VALUES_IS_NULL = "values is null";
+  private static final String STRING_IS_NULL = "string is null";
+  private static final String READER_IS_NULL = "reader is null";
+  private static final String INFINITE_AND_NAN = "Infinite and NaN values not permitted in JSON";
+
   private Json() {
     // not meant to be instantiated
   }
@@ -103,7 +109,7 @@ public static JsonValue value(long value) {
    */
   public static JsonValue value(float value) {
     if (Float.isInfinite(value) || Float.isNaN(value)) {
-      throw new IllegalArgumentException("Infinite and NaN values not permitted in JSON");
+      throw new IllegalArgumentException(INFINITE_AND_NAN);
     }
     return new JsonNumber(cutOffPointZero(Float.toString(value)));
   }
@@ -117,7 +123,7 @@ public static JsonValue value(float value) {
    */
   public static JsonValue value(double value) {
     if (Double.isInfinite(value) || Double.isNaN(value)) {
-      throw new IllegalArgumentException("Infinite and NaN values not permitted in JSON");
+      throw new IllegalArgumentException(INFINITE_AND_NAN);
     }
     return new JsonNumber(cutOffPointZero(Double.toString(value)));
   }
@@ -164,7 +170,7 @@ public static JsonArray array() {
    */
   public static JsonArray array(int... values) {
     if (values == null) {
-      throw new NullPointerException("values is null");
+      throw new NullPointerException(VALUES_IS_NULL);
     }
     JsonArray array = new JsonArray();
     for (int value : values) {
@@ -183,7 +189,7 @@ public static JsonArray array(int... values) {
    */
   public static JsonArray array(long... values) {
     if (values == null) {
-      throw new NullPointerException("values is null");
+      throw new NullPointerException(VALUES_IS_NULL);
     }
     JsonArray array = new JsonArray();
     for (long value : values) {
@@ -202,7 +208,7 @@ public static JsonArray array(long... values) {
    */
   public static JsonArray array(float... values) {
     if (values == null) {
-      throw new NullPointerException("values is null");
+      throw new NullPointerException(VALUES_IS_NULL);
     }
     JsonArray array = new JsonArray();
     for (float value : values) {
@@ -221,7 +227,7 @@ public static JsonArray array(float... values) {
    */
   public static JsonArray array(double... values) {
     if (values == null) {
-      throw new NullPointerException("values is null");
+      throw new NullPointerException(VALUES_IS_NULL);
     }
     JsonArray array = new JsonArray();
     for (double value : values) {
@@ -240,7 +246,7 @@ public static JsonArray array(double... values) {
    */
   public static JsonArray array(boolean... values) {
     if (values == null) {
-      throw new NullPointerException("values is null");
+      throw new NullPointerException(VALUES_IS_NULL);
     }
     JsonArray array = new JsonArray();
     for (boolean value : values) {
@@ -258,7 +264,7 @@ public static JsonArray array(boolean... values) {
    */
   public static JsonArray array(String... strings) {
     if (strings == null) {
-      throw new NullPointerException("values is null");
+      throw new NullPointerException(VALUES_IS_NULL);
     }
     JsonArray array = new JsonArray();
     for (String value : strings) {
@@ -289,7 +295,7 @@ public static JsonObject object() {
    */
   public static JsonValue parse(String string) {
     if (string == null) {
-      throw new NullPointerException("string is null");
+      throw new NullPointerException(STRING_IS_NULL);
     }
     DefaultHandler handler = new DefaultHandler();
     new JsonParser(handler).parse(string);
@@ -314,7 +320,7 @@ public static JsonValue parse(String string) {
    */
   public static JsonValue parse(Reader reader) throws IOException {
     if (reader == null) {
-      throw new NullPointerException("reader is null");
+      throw new NullPointerException(READER_IS_NULL);
     }
     DefaultHandler handler = new DefaultHandler();
     new JsonParser(handler).parse(reader);

com.eclipsesource.json/src/main/java/com/eclipsesource/json/JsonArray.java

@@ -62,6 +62,9 @@
 @SuppressWarnings("serial") // use default serial UID
 public class JsonArray extends JsonValue implements Iterable<JsonValue> {
 
+  // String constants
+  private static final String ARRAY_IS_NULL = "array is null";
+
   private final List<JsonValue> values;
 
   /**
@@ -83,7 +86,7 @@ public JsonArray(JsonArray array) {
 
   private JsonArray(JsonArray array, boolean unmodifiable) {
     if (array == null) {
-      throw new NullPointerException("array is null");
+      throw new NullPointerException(ARRAY_IS_NULL);
     }
     if (unmodifiable) {
       values = Collections.unmodifiableList(array.values);

com.eclipsesource.json/src/main/java/com/eclipsesource/json/JsonObject.java

@@ -72,6 +72,11 @@
 @SuppressWarnings("serial") // use default serial UID
 public class JsonObject extends JsonValue implements Iterable<Member> {
 
+  // String constants
+  private static final String OBJECT_IS_NULL = "object is null";
+  private static final String NAME_IS_NULL = "name is null";
+  private static final String VALUE_IS_NULL = "value is null";
+
   private final List<String> names;
   private final List<JsonValue> values;
   private transient HashIndexTable table;
@@ -97,7 +102,7 @@ public JsonObject(JsonObject object) {
 
   private JsonObject(JsonObject object, boolean unmodifiable) {
     if (object == null) {
-      throw new NullPointerException("object is null");
+      throw new NullPointerException(OBJECT_IS_NULL);
     }
     if (unmodifiable) {
       names = Collections.unmodifiableList(object.names);
@@ -326,10 +331,10 @@ public JsonObject add(String name, String value) {
    */
   public JsonObject add(String name, JsonValue value) {
     if (name == null) {
-      throw new NullPointerException("name is null");
+      throw new NullPointerException(NAME_IS_NULL);
     }
     if (value == null) {
-      throw new NullPointerException("value is null");
+      throw new NullPointerException(VALUE_IS_NULL);
     }
     table.add(name, names.size());
     names.add(name);
@@ -487,10 +492,10 @@ public JsonObject set(String name, String value) {
    */
   public JsonObject set(String name, JsonValue value) {
     if (name == null) {
-      throw new NullPointerException("name is null");
+      throw new NullPointerException(NAME_IS_NULL);
     }
     if (value == null) {
-      throw new NullPointerException("value is null");
+      throw new NullPointerException(VALUE_IS_NULL);
     }
     int index = indexOf(name);
     if (index != -1) {
@@ -514,7 +519,7 @@ public JsonObject set(String name, JsonValue value) {
    */
   public JsonObject remove(String name) {
     if (name == null) {
-      throw new NullPointerException("name is null");
+      throw new NullPointerException(NAME_IS_NULL);
     }
     int index = indexOf(name);
     if (index != -1) {
@@ -549,7 +554,7 @@ public boolean contains(String name) {
    */
   public JsonObject merge(JsonObject object) {
     if (object == null) {
-      throw new NullPointerException("object is null");
+      throw new NullPointerException(OBJECT_IS_NULL);
     }
     for (Member member : object) {
       this.set(member.name, member.value);
@@ -568,7 +573,7 @@ public JsonObject merge(JsonObject object) {
    */
   public JsonValue get(String name) {
     if (name == null) {
-      throw new NullPointerException("name is null");
+      throw new NullPointerException(NAME_IS_NULL);
     }
     int index = indexOf(name);
     return index != -1 ? values.get(index) : null;

com.eclipsesource.json/src/main/java/com/eclipsesource/json/JsonValue.java

@@ -63,6 +63,13 @@
 @SuppressWarnings("serial") // use default serial UID
 public abstract class JsonValue implements Serializable {
 
+  // String constants
+  private static final String NOT_A_NUMBER = "Not a number: ";
+  private static final String NOT_A_STRING = "Not a string: ";
+  private static final String NOT_A_BOOLEAN = "Not a boolean: ";
+  private static final String NOT_AN_OBJECT = "Not an object: ";
+  private static final String NOT_AN_ARRAY = "Not an array: ";
+
   /**
    * Represents the JSON literal <code>true</code>.
    * @deprecated Use <code>Json.TRUE</code> instead
@@ -287,7 +294,7 @@ public boolean isNull() {
    *           if this value is not a JSON object
    */
   public JsonObject asObject() {
-    throw new UnsupportedOperationException("Not an object: " + toString());
+    throw new UnsupportedOperationException(NOT_AN_OBJECT + toString());
   }
 
   /**
@@ -299,7 +306,7 @@ public JsonObject asObject() {
    *           if this value is not a JSON array
    */
   public JsonArray asArray() {
-    throw new UnsupportedOperationException("Not an array: " + toString());
+    throw new UnsupportedOperationException(NOT_AN_ARRAY + toString());
   }
 
   /**
@@ -318,7 +325,7 @@ public JsonArray asArray() {
    *           if this JSON number can not be interpreted as <code>int</code> value
    */
   public int asInt() {
-    throw new UnsupportedOperationException("Not a number: " + toString());
+    throw new UnsupportedOperationException(NOT_A_NUMBER + toString());
   }
 
   /**
@@ -337,7 +344,7 @@ public int asInt() {
    *           if this JSON number can not be interpreted as <code>long</code> value
    */
   public long asLong() {
-    throw new UnsupportedOperationException("Not a number: " + toString());
+    throw new UnsupportedOperationException(NOT_A_NUMBER + toString());
   }
 
   /**
@@ -353,7 +360,7 @@ public long asLong() {
    *           if this value is not a JSON number
    */
   public float asFloat() {
-    throw new UnsupportedOperationException("Not a number: " + toString());
+    throw new UnsupportedOperationException(NOT_A_NUMBER + toString());
   }
 
   /**
@@ -369,7 +376,7 @@ public float asFloat() {
    *           if this value is not a JSON number
    */
   public double asDouble() {
-    throw new UnsupportedOperationException("Not a number: " + toString());
+    throw new UnsupportedOperationException(NOT_A_NUMBER + toString());
   }
 
   /**
@@ -381,7 +388,7 @@ public double asDouble() {
    *           if this value is not a JSON string
    */
   public String asString() {
-    throw new UnsupportedOperationException("Not a string: " + toString());
+    throw new UnsupportedOperationException(NOT_A_STRING + toString());
   }
 
   /**
@@ -393,7 +400,7 @@ public String asString() {
    *           if this value is neither <code>true</code> or <code>false</code>
    */
   public boolean asBoolean() {
-    throw new UnsupportedOperationException("Not a boolean: " + toString());
+    throw new UnsupportedOperationException(NOT_A_BOOLEAN + toString());
   }
 
   /**

com.eclipsesource.json/src/main/java/com/eclipsesource/json/Location.java

@@ -22,10 +22,13 @@
 package com.eclipsesource.json;
 
 
+import java.io.Serializable;
+
 /**
  * An immutable object that represents a location in the parsed text.
  */
-public class Location {
+@SuppressWarnings("serial") // use default serial UID
+public class Location implements Serializable {
 
   /**
    * The absolute character index, starting at 0.