org.apache.flink.formats.json.JsonRowDeserializationSchema Maven / Gradle / Ivy
/*
* 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.annotation.PublicEvolving;
import org.apache.flink.api.common.serialization.DeserializationSchema;
import org.apache.flink.api.common.typeinfo.BasicArrayTypeInfo;
import org.apache.flink.api.common.typeinfo.PrimitiveArrayTypeInfo;
import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.common.typeinfo.Types;
import org.apache.flink.api.java.typeutils.ObjectArrayTypeInfo;
import org.apache.flink.api.java.typeutils.RowTypeInfo;
import org.apache.flink.types.Row;
import org.apache.flink.util.WrappingRuntimeException;
import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.core.JsonProcessingException;
import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.JsonNode;
import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.ObjectMapper;
import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.node.ArrayNode;
import org.apache.flink.shaded.jackson2.com.fasterxml.jackson.databind.node.ObjectNode;
import java.io.IOException;
import java.io.Serializable;
import java.sql.Date;
import java.sql.Time;
import java.sql.Timestamp;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.ZoneOffset;
import java.time.temporal.TemporalAccessor;
import java.time.temporal.TemporalQueries;
import java.util.Arrays;
import java.util.List;
import java.util.Objects;
import java.util.Optional;
import java.util.stream.Collectors;
import static java.lang.String.format;
import static java.time.format.DateTimeFormatter.ISO_LOCAL_DATE;
import static java.util.Spliterators.spliterator;
import static java.util.stream.StreamSupport.stream;
import static org.apache.flink.formats.json.TimeFormats.RFC3339_TIMESTAMP_FORMAT;
import static org.apache.flink.formats.json.TimeFormats.RFC3339_TIME_FORMAT;
import static org.apache.flink.util.Preconditions.checkArgument;
import static org.apache.flink.util.Preconditions.checkNotNull;
/**
* Deserialization schema from JSON to Flink types.
*
* Deserializes a byte[] message as a JSON object and reads
* the specified fields.
*
*
Failures during deserialization are forwarded as wrapped IOExceptions.
*/
@PublicEvolving
public class JsonRowDeserializationSchema implements DeserializationSchema {
private static final long serialVersionUID = -228294330688809195L;
/** Type information describing the result type. */
private final RowTypeInfo typeInfo;
private boolean failOnMissingField;
/** Object mapper for parsing the JSON. */
private final ObjectMapper objectMapper = new ObjectMapper();
private DeserializationRuntimeConverter runtimeConverter;
private JsonRowDeserializationSchema(
TypeInformation typeInfo,
boolean failOnMissingField) {
checkNotNull(typeInfo, "Type information");
checkArgument(typeInfo instanceof RowTypeInfo, "Only RowTypeInfo is supported");
this.typeInfo = (RowTypeInfo) typeInfo;
this.failOnMissingField = failOnMissingField;
this.runtimeConverter = createConverter(this.typeInfo);
}
/**
* @deprecated Use the provided {@link Builder} instead.
*/
@Deprecated
public JsonRowDeserializationSchema(TypeInformation typeInfo) {
this(typeInfo, false);
}
/**
* @deprecated Use the provided {@link Builder} instead.
*/
@Deprecated
public JsonRowDeserializationSchema(String jsonSchema) {
this(JsonRowSchemaConverter.convert(checkNotNull(jsonSchema)), false);
}
/**
* @deprecated Use the provided {@link Builder} instead.
*/
@Deprecated
public void setFailOnMissingField(boolean failOnMissingField) {
// TODO make this class immutable once we drop this method
this.failOnMissingField = failOnMissingField;
this.runtimeConverter = createConverter(this.typeInfo);
}
@Override
public Row deserialize(byte[] message) throws IOException {
try {
final JsonNode root = objectMapper.readTree(message);
return (Row) runtimeConverter.convert(objectMapper, root);
} catch (Throwable t) {
throw new IOException("Failed to deserialize JSON object.", t);
}
}
@Override
public boolean isEndOfStream(Row nextElement) {
return false;
}
@Override
public TypeInformation getProducedType() {
return typeInfo;
}
/**
* Builder for {@link JsonRowDeserializationSchema}.
*/
public static class Builder {
private final RowTypeInfo typeInfo;
private boolean failOnMissingField = false;
/**
* Creates a JSON deserialization schema for the given type information.
*
* @param typeInfo Type information describing the result type. The field names of {@link Row}
* are used to parse the JSON properties.
*/
public Builder(TypeInformation typeInfo) {
checkArgument(typeInfo instanceof RowTypeInfo, "Only RowTypeInfo is supported");
this.typeInfo = (RowTypeInfo) typeInfo;
}
/**
* Creates a JSON deserialization schema for the given JSON schema.
*
* @param jsonSchema JSON schema describing the result type
*
* @see http://json-schema.org/
*/
public Builder(String jsonSchema) {
this(JsonRowSchemaConverter.convert(checkNotNull(jsonSchema)));
}
/**
* Configures schema to fail if a JSON field is missing.
*
* By default, a missing field is ignored and the field is set to null.
*/
public Builder failOnMissingField() {
this.failOnMissingField = true;
return this;
}
public JsonRowDeserializationSchema build() {
return new JsonRowDeserializationSchema(typeInfo, failOnMissingField);
}
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (o == null || getClass() != o.getClass()) {
return false;
}
final JsonRowDeserializationSchema that = (JsonRowDeserializationSchema) o;
return Objects.equals(typeInfo, that.typeInfo) &&
Objects.equals(failOnMissingField, that.failOnMissingField);
}
@Override
public int hashCode() {
return Objects.hash(typeInfo, failOnMissingField);
}
/*
Runtime converter
*/
/**
* Runtime converter that maps between {@link JsonNode}s and Java objects.
*/
@FunctionalInterface
private interface DeserializationRuntimeConverter extends Serializable {
Object convert(ObjectMapper mapper, JsonNode jsonNode);
}
private DeserializationRuntimeConverter createConverter(TypeInformation typeInfo) {
DeserializationRuntimeConverter baseConverter = createConverterForSimpleType(typeInfo)
.orElseGet(() ->
createContainerConverter(typeInfo)
.orElseGet(() -> createFallbackConverter(typeInfo.getTypeClass())));
return wrapIntoNullableConverter(baseConverter);
}
private DeserializationRuntimeConverter wrapIntoNullableConverter(DeserializationRuntimeConverter converter) {
return (mapper, jsonNode) -> {
if (jsonNode.isNull()) {
return null;
}
return converter.convert(mapper, jsonNode);
};
}
private Optional createContainerConverter(TypeInformation typeInfo) {
if (typeInfo instanceof RowTypeInfo) {
return Optional.of(createRowConverter((RowTypeInfo) typeInfo));
} else if (typeInfo instanceof ObjectArrayTypeInfo) {
return Optional.of(createObjectArrayConverter(((ObjectArrayTypeInfo) typeInfo).getComponentInfo()));
} else if (typeInfo instanceof BasicArrayTypeInfo) {
return Optional.of(createObjectArrayConverter(((BasicArrayTypeInfo) typeInfo).getComponentInfo()));
} else if (isPrimitiveByteArray(typeInfo)) {
return Optional.of(createByteArrayConverter());
} else {
return Optional.empty();
}
}
private DeserializationRuntimeConverter createByteArrayConverter() {
return (mapper, jsonNode) -> {
try {
return jsonNode.binaryValue();
} catch (IOException e) {
throw new WrappingRuntimeException("Unable to deserialize byte array.", e);
}
};
}
private boolean isPrimitiveByteArray(TypeInformation typeInfo) {
return typeInfo instanceof PrimitiveArrayTypeInfo &&
((PrimitiveArrayTypeInfo) typeInfo).getComponentType() == Types.BYTE;
}
private DeserializationRuntimeConverter createObjectArrayConverter(TypeInformation elementTypeInfo) {
DeserializationRuntimeConverter elementConverter = createConverter(elementTypeInfo);
return assembleArrayConverter(elementConverter);
}
private DeserializationRuntimeConverter createRowConverter(RowTypeInfo typeInfo) {
List fieldConverters = Arrays.stream(typeInfo.getFieldTypes())
.map(this::createConverter)
.collect(Collectors.toList());
return assembleRowConverter(typeInfo.getFieldNames(), fieldConverters);
}
private DeserializationRuntimeConverter createFallbackConverter(Class valueType) {
return (mapper, jsonNode) -> {
// for types that were specified without JSON schema
// e.g. POJOs
try {
return mapper.treeToValue(jsonNode, valueType);
} catch (JsonProcessingException e) {
throw new WrappingRuntimeException(format("Could not convert node: %s", jsonNode), e);
}
};
}
private Optional createConverterForSimpleType(TypeInformation simpleTypeInfo) {
if (simpleTypeInfo == Types.VOID) {
return Optional.of((mapper, jsonNode) -> null);
} else if (simpleTypeInfo == Types.BOOLEAN) {
return Optional.of((mapper, jsonNode) -> jsonNode.asBoolean());
} else if (simpleTypeInfo == Types.STRING) {
return Optional.of((mapper, jsonNode) -> jsonNode.asText());
} else if (simpleTypeInfo == Types.INT) {
return Optional.of((mapper, jsonNode) -> jsonNode.asInt());
} else if (simpleTypeInfo == Types.LONG) {
return Optional.of((mapper, jsonNode) -> jsonNode.asLong());
} else if (simpleTypeInfo == Types.DOUBLE) {
return Optional.of((mapper, jsonNode) -> jsonNode.asDouble());
} else if (simpleTypeInfo == Types.FLOAT) {
return Optional.of((mapper, jsonNode) -> Float.parseFloat(jsonNode.asText().trim()));
} else if (simpleTypeInfo == Types.SHORT) {
return Optional.of((mapper, jsonNode) -> Short.parseShort(jsonNode.asText().trim()));
} else if (simpleTypeInfo == Types.BYTE) {
return Optional.of((mapper, jsonNode) -> Byte.parseByte(jsonNode.asText().trim()));
} else if (simpleTypeInfo == Types.BIG_DEC) {
return Optional.of((mapper, jsonNode) -> jsonNode.decimalValue());
} else if (simpleTypeInfo == Types.BIG_INT) {
return Optional.of((mapper, jsonNode) -> jsonNode.bigIntegerValue());
} else if (simpleTypeInfo == Types.SQL_DATE) {
return Optional.of(createDateConverter());
} else if (simpleTypeInfo == Types.SQL_TIME) {
return Optional.of(createTimeConverter());
} else if (simpleTypeInfo == Types.SQL_TIMESTAMP) {
return Optional.of(createTimestampConverter());
} else {
return Optional.empty();
}
}
private DeserializationRuntimeConverter createDateConverter() {
return (mapper, jsonNode) -> Date.valueOf(ISO_LOCAL_DATE.parse(jsonNode.asText())
.query(TemporalQueries.localDate()));
}
private DeserializationRuntimeConverter createTimestampConverter() {
return (mapper, jsonNode) -> {
// according to RFC 3339 every date-time must have a timezone;
// until we have full timezone support, we only support UTC;
// users can parse their time as string as a workaround
TemporalAccessor parsedTimestamp = RFC3339_TIMESTAMP_FORMAT.parse(jsonNode.asText());
ZoneOffset zoneOffset = parsedTimestamp.query(TemporalQueries.offset());
if (zoneOffset != null && zoneOffset.getTotalSeconds() != 0) {
throw new IllegalStateException(
"Invalid timestamp format. Only a timestamp in UTC timezone is supported yet. " +
"Format: yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
}
LocalTime localTime = parsedTimestamp.query(TemporalQueries.localTime());
LocalDate localDate = parsedTimestamp.query(TemporalQueries.localDate());
return Timestamp.valueOf(LocalDateTime.of(localDate, localTime));
};
}
private DeserializationRuntimeConverter createTimeConverter() {
return (mapper, jsonNode) -> {
// according to RFC 3339 every full-time must have a timezone;
// until we have full timezone support, we only support UTC;
// users can parse their time as string as a workaround
TemporalAccessor parsedTime = RFC3339_TIME_FORMAT.parse(jsonNode.asText());
ZoneOffset zoneOffset = parsedTime.query(TemporalQueries.offset());
LocalTime localTime = parsedTime.query(TemporalQueries.localTime());
if (zoneOffset != null && zoneOffset.getTotalSeconds() != 0 || localTime.getNano() != 0) {
throw new IllegalStateException(
"Invalid time format. Only a time in UTC timezone without milliseconds is supported yet.");
}
return Time.valueOf(localTime);
};
}
private DeserializationRuntimeConverter assembleRowConverter(
String[] fieldNames,
List fieldConverters) {
return (mapper, jsonNode) -> {
ObjectNode node = (ObjectNode) jsonNode;
int arity = fieldNames.length;
Row row = new Row(arity);
for (int i = 0; i < arity; i++) {
String fieldName = fieldNames[i];
JsonNode field = node.get(fieldName);
Object convertField = convertField(mapper, fieldConverters.get(i), fieldName, field);
row.setField(i, convertField);
}
return row;
};
}
private Object convertField(
ObjectMapper mapper,
DeserializationRuntimeConverter fieldConverter,
String fieldName,
JsonNode field) {
if (field == null) {
if (failOnMissingField) {
throw new IllegalStateException(
"Could not find field with name '" + fieldName + "'.");
} else {
return null;
}
} else {
return fieldConverter.convert(mapper, field);
}
}
private DeserializationRuntimeConverter assembleArrayConverter(DeserializationRuntimeConverter elementConverter) {
return (mapper, jsonNode) -> {
ArrayNode node = (ArrayNode) jsonNode;
return stream(spliterator(node.elements(), node.size(), 0), false)
.map(innerNode -> elementConverter.convert(mapper, innerNode))
.toArray();
};
}
}