Jackson 3 support

java-client/build.gradle.kts

@@ -222,6 +222,12 @@ dependencies {
     implementation("com.fasterxml.jackson.core", "jackson-core", jacksonVersion)
     implementation("com.fasterxml.jackson.core", "jackson-databind", jacksonVersion)
 
+    // Apache 2.0
+    // https://github.com/FasterXML/jackson
+    implementation("tools.jackson.core", "jackson-databind", "3.0.0-rc10")
+    implementation("tools.jackson.core", "jackson-core", "3.0.0-rc10")
+    implementation("com.fasterxml.jackson.core","jackson-annotations","3.0-rc5")
+
     // EPL-2.0 OR BSD-3-Clause
     // https://eclipse-ee4j.github.io/yasson/
     testImplementation("org.eclipse", "yasson", "3.0.4")

java-client/src/main/java/co/elastic/clients/json/jackson/Jackson3JsonBuffer.java

@@ -0,0 +1,113 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package co.elastic.clients.json.jackson;
+
+import co.elastic.clients.json.JsonBuffer;
+import co.elastic.clients.json.JsonData;
+import co.elastic.clients.json.JsonpDeserializer;
+import co.elastic.clients.json.JsonpMapper;
+import co.elastic.clients.json.JsonpUtils;
+
+import jakarta.json.JsonValue;
+import jakarta.json.stream.JsonGenerator;
+import jakarta.json.stream.JsonParser;
+import tools.jackson.databind.util.TokenBuffer;
+
+import java.io.StringWriter;
+import java.lang.reflect.Type;
+
+class Jackson3JsonBuffer implements JsonBuffer, JsonData {
+    private final TokenBuffer buffer;
+    private final Jackson3JsonpMapper mapper;
+
+    Jackson3JsonBuffer(TokenBuffer buffer, Jackson3JsonpMapper mapper) {
+        this.buffer = buffer;
+        this.mapper = mapper;
+    }
+
+    @Override
+    public JsonParser asParser() {
+        return new Jackson3JsonpParser(buffer.asParser(), mapper);
+    }
+
+    @Override
+    public JsonValue toJson() {
+        try (JsonParser parser = asParser()) {
+            parser.next(); // move to first event
+            return parser.getValue();
+        }
+    }
+
+    @Override
+    public JsonValue toJson(JsonpMapper mapper) {
+        // We don't need the mapper
+        return toJson();
+    }
+
+    @Override
+    public <T> T to(Type type) {
+        return to(type, this.mapper);
+    }
+
+    @Override
+    public <T> T to(Type type, JsonpMapper mapper) {
+        try (JsonParser parser = asParser()) {
+            return mapper.deserialize(parser, type);
+        }
+    }
+
+    @Override
+    public <T> T deserialize(JsonpDeserializer<T> deserializer) {
+        return deserialize(deserializer, this.mapper);
+    }
+
+    @Override
+    public <T> T deserialize(JsonpDeserializer<T> deserializer, JsonpMapper mapper) {
+        try (JsonParser parser = asParser()) {
+            return deserializer.deserialize(parser, mapper);
+        }
+    }
+
+    @Override
+    public void serialize(JsonGenerator generator, JsonpMapper mapper) {
+        if (generator instanceof Jackson3JsonpGenerator) {
+            Jackson3JsonpGenerator jkGenerator = (Jackson3JsonpGenerator) generator;
+            buffer.serialize(jkGenerator.jacksonGenerator());
+        } else {
+            try (JsonParser parser = asParser()) {
+                JsonpUtils.copy(parser, generator);
+            }
+        }
+    }
+
+    /**
+     * Renders this buffer as a JSON string for debugger and logging convenience.
+     */
+    @Override
+    public String toString() {
+        StringWriter writer = new StringWriter();
+        try (Jackson3JsonpGenerator generator =
+                 new Jackson3JsonpGenerator(mapper.objectMapper().createGenerator(writer))) {
+            serialize(generator, mapper);
+            generator.close();
+            return writer.toString();
+        }
+    }
+}