Groovy script failing for alinux server

The script :

import com.jcraft.jsch.JSch
import com.santaba.agent.util.Settings
import java.text.SimpleDateFormat
import static groovy.io.FileType.FILES
import static groovy.io.FileVisitResult.*
import groovy.time.TimeCategory
import groovy.json.*

host = hostProps.get("system.hostname")
user = hostProps.get("ssh.user")
pass = hostProps.get("ssh.pass")
port = hostProps.get("ssh.port")?.toInteger() ?: 22
cert = hostProps.get("ssh.cert") ?: '~/.ssh/id_rsa'
timeout = 15000 // timeout in milliseconds

def date = new Date()  //Get Current date stamp

def sdf = new SimpleDateFormat("MM/dd/yyyy HH:mm:ss")  //format the date for later use in the event generation
def _outArray = []
     
command = ("ps H -u mqm | wc -l") 
def command_output = getCommandOutput(command)  //run the command on the host
command_output = command_output.trim()          //the output is in string format and has multiple blnk lines, clean up blanks
command_output.eachLine         //for each of the lines in the command output
{ line ->
  int _line = line as int   //convert output to integer, this is the file count of older files if any exists
  if (_line>19000){         //if there are older files
      println _line
  }
  else{
      println _line
  }

}
 
return 0;

///////////////////////////////////////////
////////////////////////////////////////////
// DO NOT Change anything below this line
///////////////////////////////////////////
////////////////////////////////////////////

/**
 * Helper method which handles creating JSCH session and executing commands
 * @return
 */
def getCommandOutput(String input_command) {
    try {
        // instantiate JSCH object.
        jsch = new JSch()

        // do we have an user and no pass ?
        if (user && !pass) {
            // Yes, so lets try connecting via cert.
            jsch.addIdentity(cert)
        }

        // create session.
        session = jsch.getSession(user, host, port)

        // given we are running non-interactively, we will automatically accept new host keys.
        session.setConfig("StrictHostKeyChecking", "no");
        String authMethod = Settings.getSetting(Settings.SSH_PREFEREDAUTHENTICATION, Settings.DEFAULT_SSH_PREFEREDAUTHENTICATION);
        session.setConfig("PreferredAuthentications", authMethod);

        // set session timeout, in milliseconds.
        session.setTimeout(timeout)

        // is host configured with a user & password?
        if (pass) {
            // set password.
            session.setPassword(pass);
        }

        // connect
        session.connect()

        // execute command.
        channel = session.openChannel("exec")
        channel.setCommand(input_command)

        // collect command output.
        def commandOutput = channel.getInputStream()
        channel.connect()

        def output = commandOutput.text;

        // disconnect
        channel.disconnect()

        return output
    }
    catch (Exception e) {
        e.printStackTrace()
    }
    // ensure we disconnect the session.
    finally {
        session.disconnect()
    }
}

the error in debug mode:

$ !groovy
Error when executing the script - 
output:

exception:Cannot invoke method trim() on null object
java.lang.NullPointerException: Cannot invoke method trim() on null object
    at org.codehaus.groovy.runtime.NullObject.invokeMethod(NullObject.java:91)
    at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.call(PogoMetaClassSite.java:47)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47)
    at org.codehaus.groovy.runtime.callsite.NullCallSite.call(NullCallSite.java:34)
    at org.codehaus.groovy.runtime.callsite.CallSiteArray.defaultCall(CallSiteArray.java:47)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:116)
    at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:120)
    at Script759.run(Script759.groovy:20)
    at com.santaba.agent.util.GroovyScriptShell.execute(GroovyScriptShell.java:126)
    at com.santaba.agent.util.GroovyScriptExecutor.execute(GroovyScriptExecutor.java:129)
    at com.santaba.agent.debugger.GroovyTask._executeInAgent(GroovyTask.java:207)
    at com.santaba.agent.debugger.GroovyTask._handle(GroovyTask.java:186)
    at com.santaba.agent.debugger.DebugTask.run(DebugTask.java:165)
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128)
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628)
    at java.base/java.lang.Thread.run(Thread.java:829)
 

exception:Cannot invoke method trim() on null object

Your return of your command begin ran is returning nothing. You can’t trim nothing. That is basically what your error is.

An output of the failure and the code itself would help us help you.

It’s giving proper output on datasource testing

Thank you it worked.