/*
* Copyright 1999-2011 Alibaba Group.
*
* 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
*
* 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 com.alibaba.dubbo.remoting.telnet.support.command;
import java.util.ArrayList;
import java.util.List;
import com.alibaba.dubbo.common.extension.Activate;
import com.alibaba.dubbo.common.extension.ExtensionLoader;
import com.alibaba.dubbo.remoting.Channel;
import com.alibaba.dubbo.remoting.telnet.TelnetHandler;
import com.alibaba.dubbo.remoting.telnet.support.Help;
import com.alibaba.dubbo.remoting.telnet.support.TelnetUtils;
/**
* HelpTelnetHandler
*
* @author william.liangf
*/
@Activate
@Help(parameter = "[command]", summary = "Show help.", detail = "Show help.")
public class HelpTelnetHandler implements TelnetHandler {
private final ExtensionLoader<TelnetHandler> extensionLoader = ExtensionLoader.getExtensionLoader(TelnetHandler.class);
public String telnet(Channel channel, String message) {
if (message.length() > 0) {
if (! extensionLoader.hasExtension(message)) {
return "No such command " + message;
}
TelnetHandler handler = extensionLoader.getExtension(message);
Help help = handler.getClass().getAnnotation(Help.class);
StringBuilder buf = new StringBuilder();
buf.append("Command:\r\n ");
buf.append(message + " " + help.parameter().replace("\r\n", " ").replace("\n", " "));
buf.append("\r\nSummary:\r\n ");
buf.append(help.summary().replace("\r\n", " ").replace("\n", " "));
buf.append("\r\nDetail:\r\n ");
buf.append(help.detail().replace("\r\n", " \r\n").replace("\n", " \n"));
return buf.toString();
} else {
List<List<String>> table = new ArrayList<List<String>>();
List<TelnetHandler> handlers = extensionLoader.getActivateExtension(channel.getUrl(), "telnet");
if (handlers != null && handlers.size() > 0) {
for (TelnetHandler handler : handlers) {
Help help = handler.getClass().getAnnotation(Help.class);
List<String> row = new ArrayList<String>();
String parameter = " " + extensionLoader.getExtensionName(handler) + " " + (help != null ? help.parameter().replace("\r\n", " ").replace("\n", " ") : "");
row.add(parameter.length() > 50 ? parameter.substring(0, 50) + "..." : parameter);
String summary = help != null ? help.summary().replace("\r\n", " ").replace("\n", " ") : "";
row.add(summary.length() > 50 ? summary.substring(0, 50) + "..." : summary);
table.add(row);
}
}
return "Please input \"help [command]\" show detail.\r\n" + TelnetUtils.toList(table);
}
}
}