NullPointerException when trying to read Database Queries in spring batch ItemProcessor

Question

        public class TransactionHistoryCsvItemProcessor  implements ItemStream, ItemProcessor<TransactionHistory,TransactionHistory>{
            @Autowired
            private TransactionHistoryRepository transactionHistoryRepository;
            @Autowired
            private ProductHierarchyRepository productHierarchyRepository;
            @Autowired
            private LocationHierarchyRepository locationHierarchyRepository;
        
            
            List<TransactionHistory>list= transactionHistoryRepository.findAll();
            List<String> pLevel7Products = productHierarchyRepository.getPLevel7Ids();
            List<String> level5locations=locationHierarchyRepository.getLevel5Ids();
        
            
            int count=1;
            
            TransactionHistoryCsvItemProcessor(){
                
            }
            
            
            private Set<TransactionHistory> processedData = new HashSet<TransactionHistory>();
            @Override
            public TransactionHistory process(TransactionHistory transactionHistory) throws Exception {
                
                TransactionHistory processedObj = new TransactionHistory(); 
                    
                    if (pLevel7Products.contains(transactionHistory.getProductId().trim())) {
                        
                        if (level5locations.contains(transactionHistory.getLocationId().trim())) {
                        
                            if(list!=null&&!list.isEmpty()){
                                 if(list.contains(transactionHistory)){
                                     count++;
                                     throw new MyOwnException(" duplicates data error", transactionHistory.getProductId().trim(),
                                                transactionHistory.getLocationId().trim(), transactionHistory.getPeriodId(),
                                                transactionHistory.getQuantity(), "at line numer ", count-1);
                                }
                            }
                                
                                      processedObj.setProductId(transactionHistory.getProductId().trim());
                                        processedObj.setLocationId(transactionHistory.getLocationId().trim());
                                        processedObj.setQuantity(transactionHistory.getQuantity());
                                        processedObj.setPeriodId(transactionHistory.getPeriodId());
                                        processedObj.setCreatedDate(LocalDate.now());
                                        processedData.add(transactionHistory);
                                        transactionHistory.setItemCount(count);
                                        count++;
        
                        }else {
                            System.out.println("failed location");
                            count++;
                            transactionHistory.setItemCount(count);
                            throw new MyOwnException(" location data error", transactionHistory.getProductId().trim(),
                                    transactionHistory.getLocationId().trim(), transactionHistory.getPeriodId(),
                                    transactionHistory.getQuantity(), "at line numer ", count-1);
                        }
                    } else {
                        System.out.println("failed product");
                        // count++;
                        try {
                            transactionHistory.setItemCount(count);
                            throw new MyOwnException(" product data error", transactionHistory.getProductId().trim(),
                                    transactionHistory.getLocationId().trim(), transactionHistory.getPeriodId(),
                                    transactionHistory.getQuantity(), "at line numer ", count);
                        } catch (MyOwnException e) {
                            System.out.println("product error");
                            throw new MyOwnException(" product data error", transactionHistory.getProductId().trim(),
                                    transactionHistory.getLocationId().trim(), transactionHistory.getPeriodId(),
                                    transactionHistory.getQuantity(), "at line numer ", count);
        
                        } finally {
                            count++;
                        }
                    }
        
                //}
        
                if (processedObj.getProductId() == null && processedObj.getLocationId() == null)
                    return null;
                else {
                    // processedData.add(processedObj);
                    return processedObj;
                }
            }
            
            @Override
            public void open(ExecutionContext executionContext) throws ItemStreamException {
                // TODO Auto-generated method stub
                //list=transactionHistoryRepository.findAll();
            }
            @Override
            public void update(ExecutionContext executionContext) throws ItemStreamException {
                // TODO Auto-generated method stub  
            }
            @Override
            public void close() throws ItemStreamException {
                // TODO Auto-generated method stub
                count=1;    
            }
        }
    //============================================//
    @Bean
        public Step transactionHistoryStep() {
            return  ((SimpleStepBuilder<TransactionHistory, TransactionHistory>) stepBuilderFactory.get("transactionHistoryStep")
                    .<TransactionHistory,TransactionHistory>chunk(10)
                    .reader(reader())
                    .processor(processor())
                    .writer(writer())
                    .stream(new TransactionHistoryCsvItemProcessor()))
                    .faultTolerant()
                    .skipPolicy(transactionHistoryCsvImportSkipPolicy)
                    .build();
    
        }
    
    
        @Bean
        @JobScope
        public FlatFileItemReader<TransactionHistory> reader() {
            FlatFileItemReader<TransactionHistory> flatFileItemReader= new FlatFileItemReader<TransactionHistory>();
            try {
    
                TransactionHistoryFieldSetMapper transactionHistoryFieldSetMapper= new TransactionHistoryFieldSetMapper();
    
                flatFileItemReader.setResource(new FileSystemResource(FileResources.mappingFileResouces("transactionHistoryImportCsvFile")));
                flatFileItemReader.setName("CSV-Reader");
                flatFileItemReader.setLinesToSkip(1);
                flatFileItemReader.setLineMapper(new DefaultLineMapper<TransactionHistory>(){{
                    setLineTokenizer(new DelimitedLineTokenizer() {{
                        setNames("productId","locationId","periodId","quantity");
                        setFieldSetMapper(transactionHistoryFieldSetMapper);
    
                    }});
                    setFieldSetMapper(new TransactionHistoryFieldSetMapper(){{
                        //setTargetType(TransactionHistory.class);
    
                    }});
                }});
            }
            catch(Exception e) {
                e.printStackTrace();
                logger.error("read error"+flatFileItemReader);
            }
    
            return flatFileItemReader;
        }
        
        
         @Bean
         public ItemProcessor<TransactionHistory, TransactionHistory> processor() {
               return new TransactionHistoryCsvItemProcessor();
            }

//===========error ====//

Error

starting ApplicationContext. To display the conditions report re-run your application with 'debug' enabled.
2020-May-05 22:30:13.654 ERROR [main] o.s.b.SpringApplication - Application run failed
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'transactionHistoryController': Unsatisfied dependency expressed through field 'transactionHistoryCsvImportJob'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionHistoryJob' defined in class path resource [com/datalabsindia/batch/TransactionHistoryCsvImport.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.core.Job]: Factory method 'transactionHistoryJob' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionHistoryStep' defined in class path resource [com/datalabsindia/batch/TransactionHistoryCsvImport.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.core.Step]: Factory method 'transactionHistoryStep' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'processor' defined in class path resource [com/datalabsindia/batch/TransactionHistoryCsvImport.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.item.ItemProcessor]: Factory method 'processor' threw exception; nested exception is java.lang.NullPointerException
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:596)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:90)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessProperties(AutowiredAnnotationBeanPostProcessor.java:374)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1411)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:592)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:845)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
    at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:743)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:390)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:312)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1214)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1203)
    at com.datalabsindia.ScpApplication.main(ScpApplication.java:21)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionHistoryJob' defined in class path resource [com/datalabsindia/batch/TransactionHistoryCsvImport.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.core.Job]: Factory method 'transactionHistoryJob' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionHistoryStep' defined in class path resource [com/datalabsindia/batch/TransactionHistoryCsvImport.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.core.Step]: Factory method 'transactionHistoryStep' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'processor' defined in class path resource [com/datalabsindia/batch/TransactionHistoryCsvImport.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.item.ItemProcessor]: Factory method 'processor' threw exception; nested exception is java.lang.NullPointerException
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:627)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:456)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1321)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1160)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:277)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1251)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1171)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:593)
    ... 19 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.core.Job]: Factory method 'transactionHistoryJob' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionHistoryStep' defined in class path resource [com/datalabsindia/batch/TransactionHistoryCsvImport.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.core.Step]: Factory method 'transactionHistoryStep' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'processor' defined in class path resource [com/datalabsindia/batch/TransactionHistoryCsvImport.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.item.ItemProcessor]: Factory method 'processor' threw exception; nested exception is java.lang.NullPointerException
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:622)
    ... 32 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionHistoryStep' defined in class path resource [com/datalabsindia/batch/TransactionHistoryCsvImport.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.core.Step]: Factory method 'transactionHistoryStep' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'processor' defined in class path resource [com/datalabsindia/batch/TransactionHistoryCsvImport.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.item.ItemProcessor]: Factory method 'processor' threw exception; nested exception is java.lang.NullPointerException
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:627)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:456)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1321)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1160)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.resolveBeanReference(ConfigurationClassEnhancer.java:394)
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:366)
    at com.datalabsindia.batch.TransactionHistoryCsvImport$$EnhancerBySpringCGLIB$$669179a6.transactionHistoryStep(<generated>)
    at com.datalabsindia.batch.TransactionHistoryCsvImport.transactionHistoryJob(TransactionHistoryCsvImport.java:97)
    at com.datalabsindia.batch.TransactionHistoryCsvImport$$EnhancerBySpringCGLIB$$669179a6.CGLIB$transactionHistoryJob$3(<generated>)
    at com.datalabsindia.batch.TransactionHistoryCsvImport$$EnhancerBySpringCGLIB$$669179a6$$FastClassBySpringCGLIB$$d1625b5b.invoke(<generated>)
    at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244)
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:363)
    at com.datalabsindia.batch.TransactionHistoryCsvImport$$EnhancerBySpringCGLIB$$669179a6.transactionHistoryJob(<generated>)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
    ... 33 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.core.Step]: Factory method 'transactionHistoryStep' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'processor' defined in class path resource [com/datalabsindia/batch/TransactionHistoryCsvImport.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.item.ItemProcessor]: Factory method 'processor' threw exception; nested exception is java.lang.NullPointerException
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:622)
    ... 56 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'processor' defined in class path resource [com/datalabsindia/batch/TransactionHistoryCsvImport.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.item.ItemProcessor]: Factory method 'processor' threw exception; nested exception is java.lang.NullPointerException
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:627)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:456)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1321)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1160)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:555)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:515)
    at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:320)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:318)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:199)
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.resolveBeanReference(ConfigurationClassEnhancer.java:394)
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:366)
    at com.datalabsindia.batch.TransactionHistoryCsvImport$$EnhancerBySpringCGLIB$$669179a6.processor(<generated>)
    at com.datalabsindia.batch.TransactionHistoryCsvImport.transactionHistoryStep(TransactionHistoryCsvImport.java:105)
    at com.datalabsindia.batch.TransactionHistoryCsvImport$$EnhancerBySpringCGLIB$$669179a6.CGLIB$transactionHistoryStep$4(<generated>)
    at com.datalabsindia.batch.TransactionHistoryCsvImport$$EnhancerBySpringCGLIB$$669179a6$$FastClassBySpringCGLIB$$d1625b5b.invoke(<generated>)
    at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244)
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:363)
    at com.datalabsindia.batch.TransactionHistoryCsvImport$$EnhancerBySpringCGLIB$$669179a6.transactionHistoryStep(<generated>)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
    ... 57 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.item.ItemProcessor]: Factory method 'processor' threw exception; nested exception is java.lang.NullPointerException
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
    at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:622)
    ... 80 common frames omitted
Caused by: java.lang.NullPointerException: null
    at com.datalabsindia.batch.TransactionHistoryCsvItemProcessor.<init>(TransactionHistoryCsvItemProcessor.java:55)
    at com.datalabsindia.batch.TransactionHistoryCsvImport.processor(TransactionHistoryCsvImport.java:160)
    at com.datalabsindia.batch.TransactionHistoryCsvImport$$EnhancerBySpringCGLIB$$669179a6.CGLIB$processor$2(<generated>)
    at com.datalabsindia.batch.TransactionHistoryCsvImport$$EnhancerBySpringCGLIB$$669179a6$$FastClassBySpringCGLIB$$d1625b5b.invoke(<generated>)
    at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244)
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:363)
    at com.datalabsindia.batch.TransactionHistoryCsvImport$$EnhancerBySpringCGLIB$$669179a6.processor(<generated>)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
    ... 81 common frames omitted

Answer 1

The exception you are encountering is due to your attempt to use an @Autowired dependency before you have any guarantees that that dependency has been injected into your TransactionHistoryCsvItemProcessor object.

Factory method 'processor' threw exception; nested exception is java.lang.NullPointerException at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:596)

These are the problematic lines:

List<TransactionHistory>list= transactionHistoryRepository.findAll();
List<String> pLevel7Products = productHierarchyRepository.getPLevel7Ids();
List<String> level5locations=locationHierarchyRepository.getLevel5Ids();

If you need to do some additional initialization of your TransactionHistoryCsvItemProcessor object, the easiest thing to do is have TransactionHistoryCsvItemProcessor implement InitializingBean, and then initialize your Lists in the overridden method afterPropertiesSet.

For example,

public class TransactionHistoryCsvItemProcessor 
    implements InitializingBean, ItemStream, ItemProcessor<TransactionHistory,TransactionHistory>{

    @Autowired
    private TransactionHistoryRepository transactionHistoryRepository;
    @Autowired
    private ProductHierarchyRepository productHierarchyRepository;
    @Autowired
    private LocationHierarchyRepository locationHierarchyRepository;

    List<TransactionHistory> list;
    List<String> pLevel7Products;
    List<String> level5locations;

    // ...implementation omitted for brevity

    @Override
    public void afterPropertiesSet() throws Exception {
        // typical null checks would also be prudent
        list = transactionHistoryRepository.findAll();
        pLevel7Products = productHierarchyRepository.getPLevel7Ids();
        level5locations = locationHierarchyRepository.getLevel5Ids();
    }

}