Apache ZooKeeper is an open-source server which enables highly reliable distributed coordination.

Apache ZooKeeper Server Source Code files are provided in the source packge (apache-zookeeper-3.7.0.tar.gz). You can download it at Apache ZooKeeper Website.

You can also browse Apache ZooKeeper Server Source Code below:

⏎ org/apache/zookeeper/server/command/NopCommand.java

/*
 * 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.zookeeper.server.command;

import java.io.PrintWriter;
import org.apache.zookeeper.server.ServerCnxn;

/**
 * A command that does not do anything except reply to client with predefined message.
 * It is used to inform clients who execute none white listed four letter word commands.
 */
public class NopCommand extends AbstractFourLetterCommand {

    private String msg;

    public NopCommand(PrintWriter pw, ServerCnxn serverCnxn, String msg) {
        super(pw, serverCnxn);
        this.msg = msg;
    }

    @Override
    public void commandRun() {
        pw.println(msg);
    }

}

⏎ org/apache/zookeeper/server/command/NopCommand.java

Or download all of them as a single archive file:

File name: zookeeper-server-3.7.0-fyi.zip
File size: 871011 bytes
Release date: 2021-05-17
Download 

⇒ Apache ZooKeeper 3.7.0 Jute Source Code

⇐ Download Apache ZooKeeper 3.7.0 Source Package

⇑ Downloading and Reviewing zookeeper.jar

⇑⇑ FAQ for Apache ZooKeeper