本來想將寫的代碼掛在crontab下運行，誰知道無法運行，沒有任何輸出，試着用ls -al >> 1.log試了一下，確定crontab是正常運行的。
從網站上找了下問題，原因出在crontab啟動的程序並不會加載環境變量，因此像“java”這種命令是無法啟動的。
解決方案就是講java換做具體的java路徑。
步驟如下：
1. 運行命令crontab -e加入要運行的命令，並配置其運行頻次
30 01 * * * /opt/changedig/app/module/rcproject/rcproject.sh
2. 修改啟動腳本，將java路徑換做絕對路徑
#!/bin/sh
WORK_DIR="/opt/changedig/app/module/rcproject"
MYNAME="rcproject"
pidfile=.$MYNAME.pid
if test -f $WORK_DIR/$pidfile
then
# See if a process is running with that process id
pid=`cat $WORK_DIR/$pidfile`
if test -n "$pid"
then
ps -ef|grep $MYNAME|grep -v grep|awk '{print $2}'|grep $pid > /dev/null
if test $? -eq 0
then
# The process is running !
printf "The process is running !\n"
exit 3
else
# Try the ps listing again as it is not always reliable
ps -ef|grep $MYNAME|grep -v grep|awk '{print $2}'|grep $pid > /dev/null
if test $? -eq 0
then
# The process is running !
printf "The process is running !\n"
exit 3
fi
fi
fi
fi
echo $$>$WORK_DIR/$pidfile
# Check process is existence
if [ ! -f $WORK_DIR/rcproject-0.0.1.jar ] ; then
printf "Error: Can not find the file $WORK_DIR/rcproject-*.jar\n"
return 2
fi
/usr/local/java/jdk1.7.0_45/bin/java -jar $WORK_DIR/rcproject-0.0.1.jar
如此即可