How to run a Java Application from Bash Script

November 9, 2009

As one that seldom finds himself having to run Java Applications from a Unix Bash Script, I thought it would be helpful to share the appropriate commands i use to execute the code and to notify the user of success or failure. For reference the folder structure I use is:

app_name
    - lib
    - config

where the lib folder contains all necessary jar files to run the application, and the config folder contains any properties or configuration files passed as run time arguments

Writing the script

Specify the script is a bash script
```
#!/bin/bash
```
Define SUCCESS and FAILURE variables
```
FAILURE=1
SUCCESS=0
```
Define the appdirectory
```
APP_HOME=/tmp/app
```
Define the lib folder variable
```
LIB=${APP_HOME}/lib/
```
Define the classpath variable. This is a : seperated list of jars needed by the application
```
CP=${LIB}abc.jar:${LIB}xyz.jar
```

Define java home

APP_JAVA_HOME=/usr/jdk/instances/jdk1.5.0

Execute the Application with any arguments and java settings

${APP_JAVA_HOME}/bin/java -ms256m -cp "${CP}"
  com.mdibtz.TestApp "${APP_HOME}/config/config.properties"

Test for Failure

if [ $? -ne 0 ]
then
    exit ${FAILURE}
fi

Success Logic if needed
```
exit ${SUCCESS}
```

Complete Script

#!/bin/bash

FAILURE=1
SUCCESS=0

APP_HOME=`pwd`
LIB=${APP_HOME}/lib/

CP=${LIB}activation-1.1.jar:${LIB}mail-1.4.jar

APP_JAVA_HOME=/usr/jdk/instances/jdk1.5.0

${APP_JAVA_HOME}/bin/java -ms256m -mx768m -cp "${CP}" 
  com.mdbitz.TestApp "${APP_HOME}/config/config.properties"

if [ $? -ne 0 ]
then
    echo "AppFailed during run"
    exit ${FAILURE}
fi

echo "App successfully run"
exit ${SUCCESS}