Hi All, I am using Drools 4.0.3 I have the following in drl file. package com.framework.service.remote.rules; import com.framework.service.EssRuleConditionService; import com.framework.service.util.CurrentLeg; import java.util.ArrayList; import java.util.List; import java.lang.Boolean; function List depStationFun68307cu() { EssRuleConditionService essRuleConditionService = new EssRuleConditionService(); essRuleConditionService.setDepStation("21618"); return essRuleConditionService.getDepStation(); } function List depStationFun68308cu() { EssRuleConditionService essRuleConditionService = new EssRuleConditionService(); essRuleConditionService.setDepStation("20932"); return essRuleConditionService.getDepStation(); } function List depStationFun68309cu() { EssRuleConditionService essRuleConditionService = new EssRuleConditionService(); essRuleConditionService.setDepStation("21972"); return essRuleConditionService.getDepStation(); } rule "68307" dialect "java" when currentLeg : CurrentLeg() eval(currentLeg.getORGSTN().size()!=0 && depStationFun68307cu().containsAll(currentLeg.getORGSTN())) then currentLeg.setDataProcessedByDrool(new Boolean(true)); currentLeg.setRuleSetId("9003"); currentLeg.setFssBoardDailyLegId(""); end rule "68308" dialect "java" when currentLeg : CurrentLeg() eval(currentLeg.getORGSTN().size()!=0 && depStationFun68308cu().containsAll(currentLeg.getORGSTN())) then currentLeg.setDataProcessedByDrool(new Boolean(true)); currentLeg.setRuleSetId("9003"); currentLeg.setRuleSetCategoryId("15722"); currentLeg.setFssBoardDailyLegId(""); end rule "68309" dialect "java" when currentLeg : CurrentLeg() eval(currentLeg.getORGSTN().size()!=0 && depStationFun68309cu().containsAll(currentLeg.getORGSTN())) then currentLeg.setDataProcessedByDrool(new Boolean(true)); currentLeg.setRuleSetId("9003"); currentLeg.setRuleSetCategoryId("15722"); currentLeg.setFssBoardDailyLegId(""); end I have the following code to access drl file : // get the .drl constructed as inputstream // droolsInputString is drl file read into String. // I dont have any issue reading the file but i get the null pointer exception byte[] bytesOfDRL = droolsInputString.getBytes(); InputStream inputStream = new ByteArrayInputStream(bytesOfDRL); Reader source = new InputStreamReader(inputStream); PackageBuilderConfiguration conf = new PackageBuilderConfiguration(); PackageBuilder builder = new PackageBuilder(conf); builder.addPackageFromDrl(source); // when the last line is executed. builder.addPackageFromDrl(source); Here i get the following exception 17:57:50,776 ERROR [STDERR] java.lang.NullPointerException 17:57:50,776 ERROR [STDERR] at org.drools.rule.builder.dialect.java.JavaConsequenceBuilder.build(JavaConsequenceBuilder.java:54) 17:57:50,776 ERROR [STDERR] at org.drools.rule.builder.RuleBuilder.build(RuleBuilder.java:67) 17:57:50,776 ERROR [STDERR] at org.drools.compiler.PackageBuilder.addRule(PackageBuilder.java:446) 17:57:50,791 ERROR [STDERR] at org.drools.compiler.PackageBuilder.addPackage(PackageBuilder.java:304) 17:57:50,791 ERROR [STDERR] at org.drools.compiler.PackageBuilder.addPackageFromDrl(PackageBuilder.java:167) 17:57:50,791 ERROR [STDERR] at com.egatematrix.ess.framework.service.remote.rules.RulesEngineInvoker.readRule(RulesEngineInvoker.java:108) 17:57:50,791 ERROR [STDERR] at com.egatematrix.ess.framework.service.RuleService.doProcess(RuleService.java:302) 17:57:50,791 ERROR [STDERR] at com.egatematrix.ess.framework.service.FetchFSSData.invokeRuleService(FetchFSSData.java:141) 17:57:50,791 ERROR [STDERR] at com.egatematrix.ess.framework.service.FetchFSSData.triggerData(FetchFSSData.java:69) 17:57:50,791 ERROR [STDERR] at com.egatematrix.ess.framework.service.FetchFSSData$1.run(FetchFSSData.java:85) 17:57:50,791 ERROR [STDERR] at java.util.TimerThread.mainLoop(Timer.java:512) 17:57:50,791 ERROR [STDERR] at java.util.TimerThread.run(Timer.java:462) I have tried compiling the drl file in drl editor. There is no error in drl file. Can any one help me resolving the issue? Regards, Shiva Tel: +91-40-27782000 Ext: 4259