Move/add annotations and reformat code

src/main/java/io/github/orangain/jsonmatch/JsonMatch.java

@@ -7,6 +7,7 @@
 import io.github.orangain.jsonmatch.json.JsonUtil;
 import io.github.orangain.jsonmatch.parser.JsonMatchPatternParser;
 import io.github.orangain.jsonmatch.pattern.JsonPatternNode;
+import org.jetbrains.annotations.NotNull;
 
 import java.util.Optional;
 
@@ -16,7 +17,8 @@
 public class JsonMatch {
     /**
      * Asserts that the actual JSON matches the pattern JSON.
-     * @param actualJson The actual JSON string.
+     *
+     * @param actualJson  The actual JSON string.
      * @param patternJson The pattern JSON string.
      */
     public static void assertJsonMatches(String actualJson, String patternJson) {
@@ -28,11 +30,12 @@ public static void assertJsonMatches(String actualJson, String patternJson) {
 
     /**
      * Checks if the actual JSON matches the pattern JSON.
-     * @param actualJson The actual JSON string.
+     *
+     * @param actualJson  The actual JSON string.
      * @param patternJson The pattern JSON string.
      * @return An {@link Optional} of {@link JsonMatchError} if the actual JSON does not match the pattern JSON.
      */
-    public static Optional<JsonMatchError> jsonMatches(String actualJson, String patternJson) {
+    public static @NotNull Optional<JsonMatchError> jsonMatches(String actualJson, String patternJson) {
         ObjectMapper mapper = JsonUtil.getObjectMapper();
         JsonNode actualTree;
         JsonNode patternTree;

src/main/java/io/github/orangain/jsonmatch/JsonMatchError.java

@@ -7,14 +7,15 @@
  */
 public class JsonMatchError {
 
-    private final String message;
-    private final String actual;
-    private final String expected;
+    private final @NotNull String message;
+    private final @NotNull String actual;
+    private final @NotNull String expected;
 
     /**
      * Constructor of the JSON match error.
-     * @param message The error message.
-     * @param actual The actual JSON string.
+     *
+     * @param message  The error message.
+     * @param actual   The actual JSON string.
      * @param expected The expected JSON string.
      */
     public JsonMatchError(@NotNull String message, @NotNull String actual, @NotNull String expected) {
@@ -25,25 +26,28 @@ public JsonMatchError(@NotNull String message, @NotNull String actual, @NotNull
 
     /**
      * Get the error message.
+     *
      * @return The error message.
      */
-    public String getMessage() {
+    public @NotNull String getMessage() {
         return message;
     }
 
     /**
      * Get the actual JSON string.
+     *
      * @return The actual JSON string.
      */
-    public String getActual() {
+    public @NotNull String getActual() {
         return actual;
     }
 
     /**
      * Get the expected JSON string.
+     *
      * @return The expected JSON string.
      */
-    public String getExpected() {
+    public @NotNull String getExpected() {
         return expected;
     }
 }

src/main/java/io/github/orangain/jsonmatch/JsonStringAssert.java

@@ -1,6 +1,7 @@
 package io.github.orangain.jsonmatch;
 
 import org.assertj.core.api.AbstractAssert;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * AssertJ assertion for JSON strings.
@@ -9,7 +10,8 @@ public class JsonStringAssert extends AbstractAssert<JsonStringAssert, String> {
 
     /**
      * Constructor of the JSON string assertion.
-     * @param s The JSON string to make assertions on.
+     *
+     * @param s        The JSON string to make assertions on.
      * @param selfType The class of the assertion.
      */
     public JsonStringAssert(String s, Class<?> selfType) {
@@ -18,19 +20,21 @@ public JsonStringAssert(String s, Class<?> selfType) {
 
     /**
      * Creates a new instance of JsonStringAssert allowing to perform assertions on the provided JSON string.
+     *
      * @param actual The JSON string to make assertions on.
      * @return A new instance of JsonStringAssert.
      */
-    public static JsonStringAssert assertThat(String actual) {
+    public static @NotNull JsonStringAssert assertThat(String actual) {
         return new JsonStringAssert(actual, JsonStringAssert.class);
     }
 
     /**
      * Asserts that the JSON string matches the pattern JSON string.
+     *
      * @param patternJson The pattern JSON string.
      * @return This assertion object.
      */
-    public JsonStringAssert jsonMatches(String patternJson) {
+    public @NotNull JsonStringAssert jsonMatches(String patternJson) {
         isNotNull();
 
         JsonMatch.jsonMatches(actual, patternJson)

src/main/java/io/github/orangain/jsonmatch/json/JsonPath.java

@@ -6,15 +6,16 @@
  * Simple subset of JSON path. It supports only root, array item, and object field.
  */
 public class JsonPath {
-    private final String path;
+    private final @NotNull String path;
 
     /**
      * The root JSON path.
      */
-    public static JsonPath ROOT = new JsonPath("$");
+    public static @NotNull JsonPath ROOT = new JsonPath("$");
 
     /**
      * Constructor of the JSON path.
+     *
      * @param path The JSON path string.
      */
     public JsonPath(@NotNull String path) {
@@ -23,21 +24,21 @@ public JsonPath(@NotNull String path) {
 
     /**
      * Get the JSON path for the array item.
+     *
      * @param index The index of the array item.
      * @return The JSON path for the array item.
      */
-    @NotNull
-    public JsonPath arrayItem(int index) {
+    public @NotNull JsonPath arrayItem(int index) {
         return new JsonPath(path + "[" + index + "]");
     }
 
     /**
      * Get the JSON path for the object field.
+     *
      * @param fieldName The name of the object field.
      * @return The JSON path for the object field.
      */
-    @NotNull
-    public JsonPath objectField(@NotNull String fieldName) {
+    public @NotNull JsonPath objectField(@NotNull String fieldName) {
         return new JsonPath(path + "." + fieldName);
     }
 

src/main/java/io/github/orangain/jsonmatch/json/JsonUtil.java

@@ -2,18 +2,21 @@
 
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 /**
  * JSON utility class.
  */
 public class JsonUtil {
-    private static ObjectMapper objectMapper;
+    private static @Nullable ObjectMapper objectMapper = null;
 
     /**
      * Get the singleton instance of the Jackson {@link ObjectMapper}.
+     *
      * @return The singleton instance of the Jackson {@link ObjectMapper}.
      */
-    public static ObjectMapper getObjectMapper() {
+    public static @NotNull ObjectMapper getObjectMapper() {
         if (objectMapper == null) {
             objectMapper = new ObjectMapper();
         }
@@ -22,10 +25,11 @@ public static ObjectMapper getObjectMapper() {
 
     /**
      * Convert an object to a JSON string. This method is unchecked exception version of {@link ObjectMapper#writeValueAsString(Object)}.
+     *
      * @param value The object to convert to a JSON string.
      * @return The JSON string.
      */
-    public static String toJsonString(Object value) {
+    public static @NotNull String toJsonString(Object value) {
         try {
             return getObjectMapper().writeValueAsString(value);
         } catch (JsonProcessingException e) {

src/main/java/io/github/orangain/jsonmatch/parser/JsonMatchPatternParser.java

@@ -15,15 +15,15 @@
  * Parser for JSON match patterns.
  */
 public class JsonMatchPatternParser {
-    private static final Pattern ARRAY_PATTERN = Pattern.compile("\\A#\\[(\\d*)\\](.*)\\z");
+    private static final @NotNull Pattern ARRAY_PATTERN = Pattern.compile("\\A#\\[(\\d*)\\](.*)\\z");
 
     /**
      * Parse a JSON match pattern from a JSON node.
+     *
      * @param jsonNode The JSON node to parse.
      * @return The parsed JSON match pattern node.
      */
-    @NotNull
-    public static JsonPatternNode parse(@NotNull JsonNode jsonNode) {
+    public static @NotNull JsonPatternNode parse(@NotNull JsonNode jsonNode) {
         if (jsonNode.isObject()) {
             return parseObject(jsonNode);
         } else if (jsonNode.isArray()) {
@@ -33,8 +33,7 @@ public static JsonPatternNode parse(@NotNull JsonNode jsonNode) {
         }
     }
 
-    @NotNull
-    private static JsonPatternNode parseObject(@NotNull JsonNode jsonNode) {
+    private static @NotNull JsonPatternNode parseObject(@NotNull JsonNode jsonNode) {
         Map<String, JsonPatternNode> children = new HashMap<>();
         for (Iterator<Map.Entry<String, JsonNode>> it = jsonNode.fields(); it.hasNext(); ) {
             Map.Entry<String, JsonNode> entry = it.next();
@@ -45,8 +44,7 @@ private static JsonPatternNode parseObject(@NotNull JsonNode jsonNode) {
         return new ObjectLiteralPatternNode(jsonNode.toString(), children);
     }
 
-    @NotNull
-    private static JsonPatternNode parseArray(@NotNull JsonNode jsonNode) {
+    private static @NotNull JsonPatternNode parseArray(@NotNull JsonNode jsonNode) {
         List<JsonPatternNode> children = new ArrayList<>();
         for (int i = 0; i < jsonNode.size(); i++) {
             JsonNode childNode = jsonNode.get(i);
@@ -56,8 +54,7 @@ private static JsonPatternNode parseArray(@NotNull JsonNode jsonNode) {
         return new ArrayLiteralPatternNode(jsonNode.toString(), children);
     }
 
-    @NotNull
-    private static JsonPatternNode parseSimpleValue(@NotNull JsonNode jsonNode) {
+    private static @NotNull JsonPatternNode parseSimpleValue(@NotNull JsonNode jsonNode) {
         if (jsonNode.isTextual()) {
             JsonPatternNode parsed = parseMarkerOrNull(jsonNode.textValue());
             if (parsed != null) {
@@ -68,8 +65,7 @@ private static JsonPatternNode parseSimpleValue(@NotNull JsonNode jsonNode) {
         return new ValueLiteralPatternNode(jsonNode);
     }
 
-    @Nullable
-    private static JsonPatternNode parseMarkerOrNull(@NotNull String value) {
+    private static @Nullable JsonPatternNode parseMarkerOrNull(@NotNull String value) {
         if (!value.startsWith("#")) {
             return null;
         }
@@ -97,8 +93,7 @@ private static JsonPatternNode parseMarkerOrNull(@NotNull String value) {
         }
     }
 
-    @Nullable
-    private static JsonPatternNode parseValueMarkerOrNull(@NotNull String value) {
+    private static @Nullable JsonPatternNode parseValueMarkerOrNull(@NotNull String value) {
         switch (value) {
             case "#array":
                 return new ArrayMarkerPatternNode(JsonUtil.toJsonString(value));
@@ -127,8 +122,7 @@ private static JsonPatternNode parseValueMarkerOrNull(@NotNull String value) {
         return parseArrayMarkerOrNull(value);
     }
 
-    @Nullable
-    private static JsonPatternNode parseArrayMarkerOrNull(@NotNull String value) {
+    private static @Nullable JsonPatternNode parseArrayMarkerOrNull(@NotNull String value) {
         Matcher arrayMatcher = ARRAY_PATTERN.matcher(value);
         if (arrayMatcher.matches()) {
             String length = arrayMatcher.group(1);

src/main/java/io/github/orangain/jsonmatch/pattern/ArrayLiteralPatternNode.java

@@ -11,30 +11,29 @@
  * JSON array pattern node that matches a JSON array with a fixed number of elements and specific patterns for each element.
  */
 public class ArrayLiteralPatternNode extends ArrayPatternNode {
-    private final List<JsonPatternNode> expectedChildren;
+    private final @NotNull List<JsonPatternNode> expectedChildren;
 
     /**
      * Constructor of the JSON array pattern node.
-     * @param expected The string representation of the expected JSON array pattern.
+     *
+     * @param expected         The string representation of the expected JSON array pattern.
      * @param expectedChildren The expected patterns for each element of the array.
      */
-    public ArrayLiteralPatternNode(@NotNull String expected, List<JsonPatternNode> expectedChildren) {
+    public ArrayLiteralPatternNode(@NotNull String expected, @NotNull List<JsonPatternNode> expectedChildren) {
         super(expected);
         this.expectedChildren = expectedChildren;
     }
 
-    @NotNull
     @Override
-    protected Optional<JsonMatchErrorDetail> sizeMatches(@NotNull JsonPath jsonPath, @NotNull JsonNode actualNode) {
+    protected @NotNull Optional<JsonMatchErrorDetail> sizeMatches(@NotNull JsonPath jsonPath, @NotNull JsonNode actualNode) {
         if (expectedChildren.size() != actualNode.size()) {
             return Optional.of(error(jsonPath, actualNode, "actual and expected arrays are not the same size - " + actualNode.size() + ":" + expectedChildren.size()));
         }
         return Optional.empty();
     }
 
-    @NotNull
     @Override
-    protected Optional<JsonMatchErrorDetail> childrenMatches(@NotNull JsonPath jsonPath, @NotNull JsonNode actualNode) {
+    protected @NotNull Optional<JsonMatchErrorDetail> childrenMatches(@NotNull JsonPath jsonPath, @NotNull JsonNode actualNode) {
         for (int i = 0; i < expectedChildren.size(); i++) {
             Optional<JsonMatchErrorDetail> error = expectedChildren.get(i).matches(jsonPath.arrayItem(i), actualNode.get(i));
             if (error.isPresent()) {

src/main/java/io/github/orangain/jsonmatch/pattern/ArrayMarkerPatternNode.java

@@ -18,10 +18,11 @@ public class ArrayMarkerPatternNode extends ArrayPatternNode {
     /**
      * The expected pattern for each element of the array. Null means any child pattern is allowed.
      */
-    private final JsonPatternNode expectedChildPattern;
+    private final @Nullable JsonPatternNode expectedChildPattern;
 
     /**
      * Constructor of the JSON array pattern node with no expected size or child pattern.
+     *
      * @param expected The string representation of the expected JSON array pattern.
      */
     public ArrayMarkerPatternNode(@NotNull String expected) {
@@ -30,7 +31,8 @@ public ArrayMarkerPatternNode(@NotNull String expected) {
 
     /**
      * Constructor of the JSON array pattern node with child pattern but no expected size.
-     * @param expected The string representation of the expected JSON array pattern.
+     *
+     * @param expected             The string representation of the expected JSON array pattern.
      * @param expectedChildPattern The expected pattern for each element of the array.
      */
     public ArrayMarkerPatternNode(@NotNull String expected, @Nullable JsonPatternNode expectedChildPattern) {
@@ -39,8 +41,9 @@ public ArrayMarkerPatternNode(@NotNull String expected, @Nullable JsonPatternNod
 
     /**
      * Constructor of the JSON array pattern node with expected size and child pattern.
-     * @param expected The string representation of the expected JSON array pattern.
-     * @param expectedSize The expected size of the array.
+     *
+     * @param expected             The string representation of the expected JSON array pattern.
+     * @param expectedSize         The expected size of the array.
      * @param expectedChildPattern The expected pattern for each element of the array.
      */
     public ArrayMarkerPatternNode(@NotNull String expected, int expectedSize, @Nullable JsonPatternNode expectedChildPattern) {
@@ -49,19 +52,17 @@ public ArrayMarkerPatternNode(@NotNull String expected, int expectedSize, @Nulla
         this.expectedChildPattern = expectedChildPattern;
     }
 
-    @NotNull
     @Override
-    protected Optional<JsonMatchErrorDetail> sizeMatches(@NotNull JsonPath jsonPath, @NotNull JsonNode actualNode) {
+    protected @NotNull Optional<JsonMatchErrorDetail> sizeMatches(@NotNull JsonPath jsonPath, @NotNull JsonNode actualNode) {
         if (expectedSize >= 0 && expectedSize != actualNode.size()) {
             return Optional.of(error(jsonPath, actualNode, "actual array length was: " + actualNode.size()));
         }
 
         return Optional.empty();
     }
 
-    @NotNull
     @Override
-    protected Optional<JsonMatchErrorDetail> childrenMatches(@NotNull JsonPath jsonPath, @NotNull JsonNode actualNode) {
+    protected @NotNull Optional<JsonMatchErrorDetail> childrenMatches(@NotNull JsonPath jsonPath, @NotNull JsonNode actualNode) {
         if (expectedChildPattern == null) return Optional.empty();
 
         for (int i = 0; i < actualNode.size(); i++) {