Archive for 三月 26th, 2010

HelloWorld Java 2: Arguments & Signal

使用apache的commons.cli解析命令行参数
Java Code:

package test.helloworld.cmd;
// fallseir 2010-03-26
import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.GnuParser;
import org.apache.commons.cli.HelpFormatter;
import org.apache.commons.cli.Option;
import org.apache.commons.cli.OptionBuilder;
import org.apache.commons.cli.Options;
import org.apache.commons.cli.ParseException;

public class Cli {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		GnuParser parser=new GnuParser();
		Options opts=getCmdOptions();
		CommandLine line=null;
		try {
			line=parser.parse(opts,args);
		} catch (ParseException e) {
			//e.printStackTrace();
			System.err.println(e.getMessage());
			HelpFormatter helper=new HelpFormatter();
			helper.printHelp("cmdLineSyntax", opts);
		}
		if(line==null) return ;
		if(line.hasOption("h")){
			HelpFormatter helper=new HelpFormatter();
			//helper.printHelp("cmdLineSyntax", opts);
			helper.printHelp(80, "tester", "header", opts, "footer");
			return;
		}
		boolean debug=false;
		if(line.hasOption("debug")){
			debug=true;
			System.out.println("debug is set");
		}
		if(line.hasOption("arg")){
			String arg=line.getOptionValue("arg");
			System.out.println("arg "+arg);
		}
	}

	private static Options getCmdOptions() {
		Options options=new Options();
		Option opt=OptionBuilder.create("debug");
		options.addOption(opt);
		opt=OptionBuilder.isRequired()
					.hasArg()
					.withArgName("arg")
					.withDescription("arg description")
					.withLongOpt("argument")
					.withValueSeparator()
					.create("arg");
		options.addOption(opt);
		options.addOption(new Option("h","help",false,"print help"));
		return options;
	}

}

Signal Shell下基于信号的应用通信
使用 sun.misc.Signal ,但 sun 已经提示Signal将在其后版本剥离
建议使用 socket 进行通信吧

package test.helloworld.cmd;
// fallseir 2010-03-26
import sun.misc.Signal;
import sun.misc.SignalHandler;

public class SignalHandle {
	public static void main(String args[]){
		System.out.println("start");
		SignalHandle cmd=new SignalHandle();
		if(cmd.isLinux()){
			cmd.installSignalHandler("QUIT");
			cmd.installSignalHandler("HUP");
			cmd.installSignalHandler("USR1");
			cmd.installSignalHandler("USR2");
			cmd.installSignalHandler("PIPE");
		}
		cmd.installSignalHandler("TERM");
		cmd.installSignalHandler("ABRT");
		cmd.installSignalHandler("INT");
		try{
			Thread.sleep(1000*10*10);
		}catch(InterruptedException e){
			e.printStackTrace();
		}
	}
	private void handleSignal(String signal){
		System.out.println("handleSignal "+signal);
	}
	private boolean isLinux() {
		return System.getProperty("os.name").indexOf("Linux")>=0;
	}
	private void installSignalHandler(String signal){
		System.out.println("installCheckSignal "+signal);
		SimpleSignalHandler shandler=new SimpleSignalHandler();
		try{
			SignalHandler old = Signal.handle( new Signal( signal ), shandler);
			shandler.setOld(old);
		}catch(Exception e){
			System.err.println("installShutdownSignal "+signal+" "+e);
		}
	}
	class SimpleSignalHandler implements SignalHandler{
		SignalHandler old=null;
		public SimpleSignalHandler() {
		}
		public void handle( Signal sig ) {
			try{
				System.out.println("Handle Signal "+sig.getName() );
				handSignal(sig);
				if( old != null && old != SIG_DFL && old != SIG_IGN ) {  //chain back to previous handler if one exists
					old.handle( sig );
				}
			}
			catch( Throwable t ) {
				System.out.println(String.format("ShutdownSignalHandler.handle %s : %s",sig.getName(),t.getMessage())+t);
			}
		}
		protected void handSignal(Signal sig) {
			handleSignal(sig.getName());
		}
		public void setOld(SignalHandler old){
			this.old=old;
		}
	}
}

HelloWorld Java 1: ShutdownHook & start/stop Script

Java 代码:

package test.helloworld.cmd;
// by fallseir 2010-03-26
public class ShutdownHook {
	public static void main(String args[]){
		System.out.println("start");
		ShutdownHook cmd=new ShutdownHook();
		cmd.installShutdownHook();
		try{
			Thread.sleep(1000*10*10);
		}catch(InterruptedException e){
			e.printStackTrace();
		}
	}
	private void shutdown(){
		System.out.println("shutdown");
	}
	private void installShutdownHook(){
		Runtime.getRuntime().addShutdownHook(new Thread(){
			public void run(){
				shutdown();
			}
		});
	}
}

sh 代码:

#!/bin/sh
# -----------------------------------------------------------------------------
# fallseir 2010-03-26
# Start/Stop Script for the test.helloworld.cmd.ShutdownHook system
# run.sh start|stop|check
#
base="."
lib="$base/lib"
log="$base/log"

app="run"
mainCls="test.helloworld.cmd.ShutdownHook"
pid="$app"".pid"

cp=""
#cp="$cp:$lib/log4j-1.2.13.jar"

cmd="java -cp $cp $mainCls $args"

ARG=$1
if [ "x$ARG" = "x" ] ; then
  ARG="start"
else
  shift
fi

if [ ! -d "$log" ] ; then
  mkdir "$log"
fi

if [ "$ARG" = "start" ] ; then
  AppErr="$log/$app.err"
  AppOut="$log/$app.out"
  # 备份历史日志
  if [ -f "$AppErr" ] ; then
    mv "$AppErr" "$AppErr".`date +%Y%m%d`"."$$
  fi
  if [ -f "$AppOut" ] ; then
    mv "$AppOut" "$AppOut".`date +%Y%m%d`"."$$
  fi
  # 在后台启动应用
  echo "$cmd $@ > $AppOut 2> $AppErr"
  $cmd "$@" > "$AppOut" 2> "$AppOut" &
  # 记录进程ID
  if [ ! -z "$pid" ] ; then
    echo $! > $pid
  fi
# 使用USR2 进行简单通信
#elif [ "$ARG" = "check" ] ; then
#  if [ ! -z "$pid" ]; then
#    echo "check: `cat $pid`"
#    kill -USR2 `cat $pid`
#  else
#    echo "Kill failed: \$pid not set"
#  fi
elif [ "$ARG" = "stop" ] ; then
  # kill 应用进程
  if [ ! -z "$pid" ]; then
    echo "Killing: `cat $pid`"
    kill -15 `cat $pid`
    rm $pid
  else
    echo "Kill failed: \$pid not set"
  fi
fi

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