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/*
* Copyright 2024 Couchbase, Inc.
*
* Licensed 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
*
* https://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 com.couchbase.columnar.client.java;
import com.couchbase.columnar.client.java.codec.Deserializer;
import com.couchbase.columnar.client.java.codec.TypeRef;
import com.couchbase.columnar.client.java.internal.InternalJacksonSerDes;
import com.couchbase.columnar.client.java.json.JsonArray;
import com.couchbase.columnar.client.java.json.JsonObject;
import com.couchbase.columnar.client.java.json.JsonValue;
import reactor.util.annotation.Nullable;
import static java.nio.charset.StandardCharsets.UTF_8;
import static java.util.Objects.requireNonNull;
/**
* One row of a query result.
*
* Convert the row's content to a Java object by calling {@link #as}
* or {@link #asNullable}.
*
* Conversion is done by the {@link Deserializer} specified in the query
* options, or by the cluster's default deserializer if none was specified
* for the query.
*
* If you use {@code JacksonDeserializer} (the default) and enjoy
* working with Jackson's tree model, call {@code row.as(JsonNode.class)}
* to convert the row to a Jackson tree. Alternatively, pass a class whose
* fields match the structure of the row, and let Jackson bind the row data
* to a new instance of the class.
*
* Convert to a parameterized type by calling the overload that
* takes a {@link TypeRef} instead of a Class. For example:
*
* row.as(new TypeRef<Map<String, MyCustomClass>>() {});
*
*
* If you prefer to use the Couchbase Columnar SDK's simple {@link JsonValue}
* tree model, convert the row to {@link JsonObject} or {@link JsonArray}.
* These classes are not as full-featured as Jackson's tree model, but they
* are always supported regardless of which deserializer you use.
*
* Call {@link #bytes()} to get the raw bytes of the row content,
* exactly as it was received from the server. This may be useful for
* debugging, or if you want to handle deserialization yourself.
*
* @see ClusterOptions#deserializer(Deserializer)
* @see QueryOptions#deserializer(Deserializer)
*/
public final class Row {
private final byte[] content;
private final Deserializer deserializer;
Row(
byte[] content,
Deserializer deserializer
) {
this.content = requireNonNull(content);
this.deserializer = requireNonNull(deserializer);
}
/**
* Returns the raw content of the row, exactly as it was received from
* the server.
*/
public byte[] bytes() {
return content;
}
/**
* Returns the content of the row deserialized as an instance of the specified type.
*
* @throws NullPointerException if the row content is a literal null.
* @throws DataConversionException if the row could not be deserialized
* into an instance of the specified type.
*/
public T as(Class type) {
return requireNonNull(
asNullable(type),
"Row content was a literal null. If this is expected, call `row.asNullable(type)` instead of `row.as(type)`."
);
}
/**
* Returns the content of the row deserialized as an instance of the specified type,
* or null if the row's content is a literal null.
*
* @throws DataConversionException if the row could not be deserialized
* into an instance of the specified type.
*/
@Nullable
public T asNullable(Class type) {
requireNonNull(type, "`type` argument must be non-null");
try {
// Fail fast with a helpful message if user tries to
// use ObjectNode from shadowed Jackson, for example.
String corePackage = "com.couchbase.client.core";
if (type.getName().startsWith(corePackage)) {
throw new IllegalArgumentException("Classes in internal API package '" + corePackage + "' are not valid deserialization targets. Did you mean to import this class from a different package? " + type);
}
// If type is Couchbase JsonObject or JsonArray,
// always use a serializer that knows how to handle them.
return JsonValue.class.isAssignableFrom(type)
? InternalJacksonSerDes.INSTANCE.deserialize(type, content)
: deserializer.deserialize(type, content);
} catch (Exception e) {
throw new DataConversionException(e);
}
}
/**
* Returns the content of the row deserialized as an instance of the specified type.
*
* @throws NullPointerException if the row content is a literal null.
* @throws DataConversionException if the row could not be deserialized
* into an instance of the specified type.
*/
public T as(TypeRef type) {
return requireNonNull(
asNullable(type),
"Row content was a literal null. If this is expected, call `row.asNullable(type)` instead of `row.as(type)`."
);
}
/**
* Returns the content of the row deserialized as an instance of the specified type,
* or null if the row content is a literal null.
*
* @throws DataConversionException if the row could not be deserialized
* into an instance of the specified type.
*/
@Nullable
public T asNullable(TypeRef type) {
requireNonNull(type, "`type` argument must be non-null");
try {
return deserializer.deserialize(type, content);
} catch (Exception e) {
throw new DataConversionException(e);
}
}
@Override
public String toString() {
return new String(content, UTF_8);
}
}