shell checks and starts Java program

Scenes

When you want to run a Jar program you wrote on a server (Linux), the usual approach is

java -jar config.jar
#或者让其后台启动
nohup java -jar config.jar &

This will allow the program to start. However, this is not user-friendly or elegant enough. A better way would be to first determine config.jarwhether it is already running, and only execute startup if it is not running.

plan

#!/bin/sh
#NAME变量填写jar包的名字，尽可能唯一
NAME="config.jar"
RUN=0

#循环，为了让脚本一直运行监控
while [ $RUN -eq 0 ]
do
    DTTERM=`jps | grep $NAME`       #匹配程序
    if [ -n "$DTTERM" ]
    then  
        echo "PID=$( jps | grep "$NAME") is running..."
        RUN=$(( $RUN + 1 ))
    #正确输入信息到日志文件
    else
        filepath=$(cd "$(dirname "$0")"; pwd)
        echo "$NAME is not start! Going to start(dir=$filepath)..."
        echo > $filepath/log.out && nohup java -jar $filepath/$NAME > $filepath/log.out &
    fi

    sleep 2    # 每次监测时间60秒
done

exit 0

Save the above code as start.sh, in config.jarthe same directory, with the following structure

and grant permission

chmod +x start.sh

Then execute

root@xxxxxx# sh start.sh
PID=4232 config.jar is running...