本来想将写的代码挂在crontab下运行，谁知道无法运行，没有任何输出，试着用ls -al >> 1.log试了一下，确定crontab是正常运行的。
从网站上找了下问题，原因出在crontab启动的程序并不会加载环境变量，因此像“java”这种命令是无法启动的。
解决方案就是讲java换做具体的java路径。
步骤如下：
1. 运行命令crontab -e加入要运行的命令，并配置其运行频次
30 01 * * * /opt/changedig/app/module/rcproject/rcproject.sh
2. 修改启动脚本，将java路径换做绝对路径
#!/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