kafka ManCommandHandler 源码

kafka ManCommandHandler 代码

文件路径：/shell/src/main/java/org/apache/kafka/shell/ManCommandHandler.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.kafka.shell;

import net.sourceforge.argparse4j.ArgumentParsers;
import net.sourceforge.argparse4j.inf.ArgumentParser;
import net.sourceforge.argparse4j.inf.Namespace;
import org.jline.reader.Candidate;

import java.io.PrintWriter;
import java.util.List;
import java.util.Optional;

/**
 * Implements the manual command.
 */
public final class ManCommandHandler implements Commands.Handler {
    private final String cmd;

    public final static Commands.Type TYPE = new ManCommandType();

    public static class ManCommandType implements Commands.Type {
        private ManCommandType() {
        }

        @Override
        public String name() {
            return "man";
        }

        @Override
        public String description() {
            return "Show the help text for a specific command.";
        }

        @Override
        public boolean shellOnly() {
            return true;
        }

        @Override
        public void addArguments(ArgumentParser parser) {
            parser.addArgument("cmd").
                nargs(1).
                help("The command to get help text for.");
        }

        @Override
        public Commands.Handler createHandler(Namespace namespace) {
            return new ManCommandHandler(namespace.<String>getList("cmd").get(0));
        }

        @Override
        public void completeNext(MetadataNodeManager nodeManager, List<String> nextWords,
                                 List<Candidate> candidates) throws Exception {
            if (nextWords.size() == 1) {
                CommandUtils.completeCommand(nextWords.get(0), candidates);
            }
        }
    }

    public ManCommandHandler(String cmd) {
        this.cmd = cmd;
    }

    @Override
    public void run(Optional<InteractiveShell> shell,
                    PrintWriter writer,
                    MetadataNodeManager manager) {
        Commands.Type type = Commands.TYPES.get(cmd);
        if (type == null) {
            writer.println("man: unknown command " + cmd +
                ". Type help to get a list of commands.");
        } else {
            ArgumentParser parser = ArgumentParsers.newArgumentParser(type.name(), false);
            type.addArguments(parser);
            writer.printf("%s: %s%n%n", cmd, type.description());
            parser.printHelp(writer);
        }
    }

    @Override
    public int hashCode() {
        return cmd.hashCode();
    }

    @Override
    public boolean equals(Object other) {
        if (!(other instanceof ManCommandHandler)) return false;
        ManCommandHandler o = (ManCommandHandler) other;
        if (!o.cmd.equals(cmd)) return false;
        return true;
    }
}

相关信息

kafka 源码目录

相关文章

kafka CatCommandHandler 源码

kafka CdCommandHandler 源码

kafka CommandUtils 源码

kafka Commands 源码

kafka ErroneousCommandHandler 源码

kafka ExitCommandHandler 源码

kafka FindCommandHandler 源码

kafka GlobComponent 源码

kafka GlobVisitor 源码

kafka HelpCommandHandler 源码