/*
* 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.kafka.common.requests;
import org.apache.kafka.common.Node;
import org.apache.kafka.common.errors.UnsupportedVersionException;
import org.apache.kafka.common.protocol.ApiKeys;
import org.apache.kafka.common.protocol.Errors;
import org.apache.kafka.common.protocol.types.Struct;
import org.apache.kafka.common.utils.Utils;
import java.nio.ByteBuffer;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class MetadataRequest extends AbstractRequest {
public static class Builder extends AbstractRequest.Builder<MetadataRequest> {
private static final List<String> ALL_TOPICS = null;
// The list of topics, or null if we want to request metadata about all topics.
private final List<String> topics;
public static Builder allTopics() {
return new Builder(ALL_TOPICS);
}
public Builder(List<String> topics) {
super(ApiKeys.METADATA);
this.topics = topics;
}
public List<String> topics() {
return this.topics;
}
public boolean isAllTopics() {
return this.topics == ALL_TOPICS;
}
@Override
public MetadataRequest build(short version) {
if (version < 1) {
throw new UnsupportedVersionException("MetadataRequest " +
"versions older than 1 are not supported.");
}
return new MetadataRequest(this.topics, version);
}
@Override
public String toString() {
StringBuilder bld = new StringBuilder();
bld.append("(type=MetadataRequest").
append(", topics=");
if (topics == null) {
bld.append("<ALL>");
} else {
bld.append(Utils.join(topics, ","));
}
bld.append(")");
return bld.toString();
}
}
private static final String TOPICS_KEY_NAME = "topics";
private final List<String> topics;
/**
* In v0 null is not allowed and an empty list indicates requesting all topics.
* Note: modern clients do not support sending v0 requests.
* In v1 null indicates requesting all topics, and an empty list indicates requesting no topics.
*/
public MetadataRequest(List<String> topics, short version) {
super(version);
this.topics = topics;
}
public MetadataRequest(Struct struct, short version) {
super(version);
Object[] topicArray = struct.getArray(TOPICS_KEY_NAME);
if (topicArray != null) {
topics = new ArrayList<>();
for (Object topicObj: topicArray) {
topics.add((String) topicObj);
}
} else {
topics = null;
}
}
@Override
public AbstractResponse getErrorResponse(int throttleTimeMs, Throwable e) {
List<MetadataResponse.TopicMetadata> topicMetadatas = new ArrayList<>();
Errors error = Errors.forException(e);
List<MetadataResponse.PartitionMetadata> partitions = Collections.emptyList();
if (topics != null) {
for (String topic : topics)
topicMetadatas.add(new MetadataResponse.TopicMetadata(error, topic, false, partitions));
}
short versionId = version();
switch (versionId) {
case 0:
case 1:
case 2:
return new MetadataResponse(Collections.<Node>emptyList(), null, MetadataResponse.NO_CONTROLLER_ID, topicMetadatas);
case 3:
return new MetadataResponse(throttleTimeMs, Collections.<Node>emptyList(), null, MetadataResponse.NO_CONTROLLER_ID, topicMetadatas);
default:
throw new IllegalArgumentException(String.format("Version %d is not valid. Valid versions for %s are 0 to %d",
versionId, this.getClass().getSimpleName(), ApiKeys.METADATA.latestVersion()));
}
}
public boolean isAllTopics() {
return topics == null;
}
public List<String> topics() {
return topics;
}
public static MetadataRequest parse(ByteBuffer buffer, short version) {
return new MetadataRequest(ApiKeys.METADATA.parseRequest(version, buffer), version);
}
@Override
protected Struct toStruct() {
Struct struct = new Struct(ApiKeys.METADATA.requestSchema(version()));
if (topics == null)
struct.set(TOPICS_KEY_NAME, null);
else
struct.set(TOPICS_KEY_NAME, topics.toArray());
return struct;
}
}