diff --git a/core/pom.xml b/core/pom.xml
index 7a4ae06b..e5e55021 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -160,6 +160,13 @@
**/tests/draft2019-09/exclusiveMaximum.json
**/tests/draft2020-12/exclusiveMaximum.json
**/tests/draft-next/exclusiveMaximum.json
+
+ **/tests/draft4/multipleOf.json
+ **/tests/draft6/multipleOf.json
+ **/tests/draft7/multipleOf.json
+ **/tests/draft2019-09/multipleOf.json
+ **/tests/draft2020-12/multipleOf.json
+ **/tests/draft-next/multipleOf.json
diff --git a/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/basic/BasicVocabulary.java b/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/basic/BasicVocabulary.java
index 57cb0cad..0616c530 100644
--- a/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/basic/BasicVocabulary.java
+++ b/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/basic/BasicVocabulary.java
@@ -45,7 +45,8 @@ public BasicVocabulary() {
new MinimumKeywordType(),
new ExclusiveMinimumKeywordType(),
new MaximumKeywordType(),
- new ExclusiveMaximumKeywordType()
+ new ExclusiveMaximumKeywordType(),
+ new MultipleOfKeywordType()
);
}
diff --git a/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/basic/MultipleOfKeywordType.java b/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/basic/MultipleOfKeywordType.java
new file mode 100644
index 00000000..7fd33a92
--- /dev/null
+++ b/core/src/main/java/io/github/sebastiantoepfer/jsonschema/core/vocab/basic/MultipleOfKeywordType.java
@@ -0,0 +1,84 @@
+/*
+ * The MIT License
+ *
+ * Copyright 2023 sebastian.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package io.github.sebastiantoepfer.jsonschema.core.vocab.basic;
+
+import io.github.sebastiantoepfer.jsonschema.ConstraintViolation;
+import io.github.sebastiantoepfer.jsonschema.InstanceType;
+import io.github.sebastiantoepfer.jsonschema.core.vocab.ConstraintAssertion;
+import io.github.sebastiantoepfer.jsonschema.keyword.Keyword;
+import io.github.sebastiantoepfer.jsonschema.keyword.KeywordType;
+import jakarta.json.JsonNumber;
+import jakarta.json.JsonValue;
+import java.math.BigDecimal;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+import java.util.Objects;
+
+final class MultipleOfKeywordType implements KeywordType {
+
+ @Override
+ public String name() {
+ return "multipleOf";
+ }
+
+ @Override
+ public Keyword createKeyword(final JsonValue value) {
+ if (InstanceType.NUMBER.isInstance(value)) {
+ return new MultipleOfKeyword((JsonNumber) value);
+ } else {
+ throw new IllegalArgumentException("value must be a postiv number");
+ }
+ }
+
+ private class MultipleOfKeyword implements ConstraintAssertion {
+
+ private final BigDecimal multipleOf;
+
+ public MultipleOfKeyword(final JsonNumber multipleOf) {
+ this.multipleOf = multipleOf.bigDecimalValue();
+ }
+
+ @Override
+ public boolean hasName(final String name) {
+ return Objects.equals(name(), name);
+ }
+
+ @Override
+ public Collection violationsBy(final JsonValue value) {
+ final Collection result;
+ if (
+ !InstanceType.NUMBER.isInstance(value) ||
+ BigDecimal.ZERO.equals(
+ ((JsonNumber) value).bigDecimalValue().remainder(multipleOf).stripTrailingZeros()
+ )
+ ) {
+ result = Collections.emptyList();
+ } else {
+ result = List.of(new ConstraintViolation());
+ }
+ return result;
+ }
+ }
+}
diff --git a/core/src/test/java/io/github/sebastiantoepfer/jsonschema/core/vocab/basic/MultipleOfKeywordTypeTest.java b/core/src/test/java/io/github/sebastiantoepfer/jsonschema/core/vocab/basic/MultipleOfKeywordTypeTest.java
new file mode 100644
index 00000000..302c9b28
--- /dev/null
+++ b/core/src/test/java/io/github/sebastiantoepfer/jsonschema/core/vocab/basic/MultipleOfKeywordTypeTest.java
@@ -0,0 +1,95 @@
+/*
+ * The MIT License
+ *
+ * Copyright 2023 sebastian.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package io.github.sebastiantoepfer.jsonschema.core.vocab.basic;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import io.github.sebastiantoepfer.jsonschema.keyword.Keyword;
+import jakarta.json.Json;
+import jakarta.json.JsonValue;
+import java.math.BigDecimal;
+import org.junit.jupiter.api.Test;
+
+class MultipleOfKeywordTypeTest {
+
+ @Test
+ void should_know_his_name() {
+ final Keyword multipleOf = new MultipleOfKeywordType().createKeyword(Json.createValue(10));
+
+ assertThat(multipleOf.hasName("multipleOf"), is(true));
+ assertThat(multipleOf.hasName("test"), is(false));
+ }
+
+ @Test
+ void should_not_be_creatable_with_non_integer_value() {
+ final MultipleOfKeywordType keywordType = new MultipleOfKeywordType();
+ assertThrows(IllegalArgumentException.class, () -> keywordType.createKeyword(JsonValue.FALSE));
+ }
+
+ @Test
+ void should_be_valid_for_non_number_values() {
+ assertThat(
+ new MultipleOfKeywordType()
+ .createKeyword(Json.createValue(10))
+ .asAssertion()
+ .isValidFor(JsonValue.EMPTY_JSON_OBJECT),
+ is(true)
+ );
+ }
+
+ @Test
+ void should_be_valid_for_a_multipleOf() {
+ assertThat(
+ new MultipleOfKeywordType()
+ .createKeyword(Json.createValue(1.5))
+ .asAssertion()
+ .isValidFor(Json.createValue(4.5)),
+ is(true)
+ );
+ }
+
+ @Test
+ void should_be_invalid_for_non_multipleOf() {
+ assertThat(
+ new MultipleOfKeywordType()
+ .createKeyword(Json.createValue(2))
+ .asAssertion()
+ .isValidFor(Json.createValue(7)),
+ is(false)
+ );
+ }
+
+ @Test
+ void should_be_valid_for_any_int_if_multipleOf_is_1en8() {
+ assertThat(
+ new MultipleOfKeywordType()
+ .createKeyword(Json.createValue(new BigDecimal("1e-8")))
+ .asAssertion()
+ .isValidFor(Json.createValue(12391239123L)),
+ is(true)
+ );
+ }
+}