Github user xccui commented on a diff in the pull request:
https://github.com/apache/flink/pull/5491#discussion_r168439885
--- Diff:
flink-formats/flink-json/src/main/java/org/apache/flink/formats/json/JsonSchemaConverter.java
---
@@ -0,0 +1,358 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF 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 org.apache.flink.formats.json;
+
+import org.apache.flink.api.common.typeinfo.TypeInformation;
+import org.apache.flink.api.common.typeinfo.Types;
+import org.apache.flink.types.Row;
+import org.apache.flink.util.Preconditions;
+
+import
org.apache.flink.shaded.jackson2.com.fasterxml.jackson.core.JsonParser;
+import
org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.JsonNode;
+import
org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.ObjectMapper;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.Set;
+
+/**
+ * Converts a JSON schema into Flink's type information. It uses {@link
Row} for representing
+ * objects and tuple arrays.
+ *
+ * <p>Note: This converter implements just a subset of the JSON schema
specification.
+ * Union types (as well as "allOf", "anyOf", "not") are not supported yet.
Simple
+ * references that link to a common definition in the document are
supported. "oneOf" and
+ * arrays of type are only supported for specifying nullability;
+ */
+@SuppressWarnings("OptionalIsPresent")
+public final class JsonSchemaConverter {
+
+ private JsonSchemaConverter() {
+ // private
+ }
+
+ // see
https://spacetelescope.github.io/understanding-json-schema/UnderstandingJSONSchema.pdf
+ private static final String PROPERTIES = "properties";
+ private static final String ADDITIONAL_PROPERTIES =
"additionalProperties";
+ private static final String TYPE = "type";
+ private static final String FORMAT = "format";
+ private static final String CONTENT_ENCODING = "contentEncoding";
+ private static final String ITEMS = "items";
+ private static final String ADDITIONAL_ITEMS = "additionalItems";
+ private static final String REF = "$ref";
+ private static final String ALL_OF = "allOf";
+ private static final String ANY_OF = "anyOf";
+ private static final String NOT = "not";
+ private static final String ONE_OF = "oneOf";
+
+ // from https://tools.ietf.org/html/draft-zyp-json-schema-03#page-14
+ private static final String DISALLOW = "disallow";
+ private static final String EXTENDS = "extends";
+
+ private static final String TYPE_NULL = "null";
+ private static final String TYPE_BOOLEAN = "boolean";
+ private static final String TYPE_OBJECT = "object";
+ private static final String TYPE_ARRAY = "array";
+ private static final String TYPE_NUMBER = "number";
+ private static final String TYPE_INTEGER = "integer";
+ private static final String TYPE_STRING = "string";
+
+ private static final String FORMAT_DATE = "date";
+ private static final String FORMAT_TIME = "time";
+ private static final String FORMAT_DATE_TIME = "date-time";
+
+ private static final String CONTENT_ENCODING_BASE64 = "base64";
+
+ /**
+ * Converts a JSON schema into Flink's type information. Throws an
exception of the schema
--- End diff --
of -> if
---
