Getting corrupted excel file created through groovy script

Hi ,

I'm using below script to create a report of my test execution. Since some of my response body has huge size , which cannot be accommodated into an excel cell I have used a logic to just write that "reponse is too big" instead of writing  my original response. Whenever my response is huge my report is getting corrupted and some of the data is not getting written to the output file. Please suggest me on how to get this issue resolved. Attached the screenshot of error I'm getting.

import static java.nio.charset.StandardCharsets.*;
import java.lang.*;
import com.eviware.soapui.model.testsuite.Assertable.AssertionStatus
import com.eviware.soapui.impl.wsdl.teststeps.WsdlTestRequestStep
import com.eviware.soapui.support.XmlHolder
import jxl.*
import jxl.write.*
import org.skyscreamer.jsonassert.JSONAssert
import org.skyscreamer.jsonassert.JSONCompareMode
import groovy.json.JsonSlurper
def count=0,i=1,j=1,k=1,pass_count=0,fail_count=0
def inputFileName,outputFileName
def inputFile = testRunner.testCase.testSuite.getPropertyValue("inputFileName")
def outputFile = testRunner.testCase.testSuite.getPropertyValue("outputFileName")
def testStep = testRunner.testCase.testSteps["Properties"]

 

Workbook inputWB = Workbook.getWorkbook(new File(inputFile)) 
Sheet inputSheet = inputWB.getSheet(0)
no_of_rows= inputSheet.getRows().toInteger() 

 

Workbook existingInputWB=Workbook.getWorkbook(new File(inputFile))
WritableWorkbook outputWB=Workbook.createWorkbook(new File(outputFile),existingInputWB)

 

testCaseName=testRunner.testCase.name
outputWB.createSheet(testCaseName,2)
WritableSheet sheet_writable = outputWB.getSheet(testCaseName)
(0..context.testCase.testStepCount-1).each{
    def step = context.testCase.testStepList[it]
    if ( step instanceof WsdlTestRequestStep) {
        jxl.write.Label stepName =  new jxl.write.Label(0,i ,step.name)
        sheet_writable.addCell(stepName)
        def tr=testRunner.testCase.getTestStepByName(step.name)
          def String endPointUrl= tr.getHttpRequest().getResponse().getURL()
        jxl.write.Label reqUrl =  new jxl.write.Label(2,i ,endPointUrl)
        sheet_writable.addCell(reqUrl)
        def payload = context.expand(step.getPropertyValue('Request'))
        jxl.write.Label reqPayload =  new jxl.write.Label(3,i ,payload)
        sheet_writable.addCell(reqPayload)
          def response = context.expand(step.getPropertyValue('Response'))
        if(response.length()<1048576)
		{
        	jxl.write.Label reqResponse =  new jxl.write.Label(4,i ,response)
		sheet_writable.addCell(reqResponse)
		}
		else
		{
			log.info "response too big"
			jxl.write.Label reqResponse =  new jxl.write.Label(4,i ,"Response is too big")
		     sheet_writable.addCell(reqResponse)
		}
        count=count+1
        i=i+1
    }
}
def overall_status=testRunner.testCase.testSuite.getPropertyValue("overallStatus")
def TestCase = testRunner.getTestCase()
def StepList = TestCase.getTestStepList()

 

StepList.each{
    if(it.metaClass.hasProperty(it,'assertionStatus')){
        if(it.assertionStatus == AssertionStatus.FAILED){
          jxl.write.Label anotherWritableCell10 =  new jxl.write.Label(1,j ,"Failed")
          sheet_writable.addCell(anotherWritableCell10)
          fail_count=fail_count+1
        }else if(it.assertionStatus == AssertionStatus.VALID){
            jxl.write.Label anotherWritableCell10 =  new jxl.write.Label(1,j ,"Passed")
          sheet_writable.addCell(anotherWritableCell10)
          pass_count=pass_count+1
        }else if(it.assertionStatus == AssertionStatus.UNKNOWN){
            jxl.write.Label anotherWritableCell10 =  new jxl.write.Label(1,j ,"UNKNOWN (PROBABLY NOT ALREADY EXECUTED)")
          sheet_writable.addCell(anotherWritableCell10)
        }
            j=j+1
    }

 

}
if(overall_status=="Passed" && fail_count>0)
{
   testRunner.testCase.testSuite.setPropertyValue("overallStatus","Failed")
}
outputWB.write()
outputWB.close()
existingInputWB.close()

Appreciate your help in advance.