1
我重构了Spring doc for creating batch service实现一个独立的类我的读者`NullPointerException`由于失败自动装配
@Component
@PropertySource("classpath:db-config.properties")
public class CsvReader<Item> extends FlatFileItemReader<Item>{
@Autowired
private Environment env;
public CsvReader() {
this.setResource(new ClassPathResource(env.getProperty("csv_file.name")));
this.setLineMapper(new DefaultLineMapper<ImportDataItem>() {
{
setLineTokenizer(new DelimitedLineTokenizer() {
{
setNames(new String[] { "firstName", "lastName" });
}
});
}
});
}
}
NullPointerException是由env.getProperty("csv_file.name")抛出，如果它被替换文件名中的String，它的工作原理。我读过another answer &上面的代码看起来不错，所以请你帮我理解为什么Environment env不是自动装配的？
[main] INFO org.springframework.context.annotation.AnnotationConfigApplicationContext - Refreshing org.spring[email protected]5c29bfd: startup date [Thu Oct 22 11:26:18 IST 2015]; root of context hierarchy
[main] INFO org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader - Skipping bean definition for [BeanMethod:name=importDataJob,declaringClass=batch.spring.example.job.ImportDataJob]: a definition for bean 'importDataJob' already exists. This top-level bean definition is considered as an override.
[main] WARN org.springframework.context.annotation.ConfigurationClassEnhancer - @Bean method ScopeConfiguration.stepScope is non-static and returns an object assignable to Spring's BeanFactoryPostProcessor interface. This will result in a failure to process annotations such as @Autowired, @Resource and @PostConstruct within the method's declaring @Configuration class. Add the 'static' modifier to this method to avoid these container lifecycle issues; see @Bean javadoc for complete details.
[main] WARN org.springframework.context.annotation.ConfigurationClassEnhancer - @Bean method ScopeConfiguration.jobScope is non-static and returns an object assignable to Spring's BeanFactoryPostProcessor interface. This will result in a failure to process annotations such as @Autowired, @Resource and @PostConstruct within the method's declaring @Configuration class. Add the 'static' modifier to this method to avoid these container lifecycle issues; see @Bean javadoc for complete details.
[main] WARN org.springframework.context.annotation.AnnotationConfigApplicationContext - Exception encountered during context initialization - cancelling refresh attempt
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'CsvReader' defined in batch.spring.example.job.ImportDataJob: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.item.ItemReader]: Factory method 'CsvReader' threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1123)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1018)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:305)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:301)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:196)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
at org.springframework.context.annotation.AnnotationConfigApplicationContext.<init>(AnnotationConfigApplicationContext.java:84)
at batch.spring.example.ImportDataApp.main(ImportDataApp.java:24)
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.item.ItemReader]: Factory method 'CsvReader' threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189)
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588)
... 13 more
Caused by: java.lang.NullPointerException
at batch.spring.example.job.item_reader.CsvReader.<init>(CsvReader.java:28)
at batch.spring.example.job.ImportDataJob.CsvReader(ImportDataJob.java:67)
at batch.spring.example.job.ImportDataJob$$EnhancerBySpringCGLIB$$eb882444.CGLIB$CsvReader$1(<generated>)
at batch.spring.example.job.ImportDataJob$$EnhancerBySpringCGLIB$$eb882444$$FastClassBySpringCGLIB$$6d548885.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:309)
at batch.spring.example.job.ImportDataJob$$EnhancerBySpringCGLIB$$eb882444.CsvReader(<generated>)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162)
... 14 more
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'CsvReader' defined in batch.spring.example.job.ImportDataJob: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.item.ItemReader]: Factory method 'CsvReader' threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1123)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1018)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:305)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:301)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:196)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
at org.springframework.context.annotation.AnnotationConfigApplicationContext.<init>(AnnotationConfigApplicationContext.java:84)
at batch.spring.example.ImportDataApp.main(ImportDataApp.java:24)
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.item.ItemReader]: Factory method 'CsvReader' threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189)
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588)
... 13 more
Caused by: java.lang.NullPointerException
at batch.spring.example.job.item_reader.CsvReader.<init>(CsvReader.java:28)
at batch.spring.example.job.ImportDataJob.CsvReader(ImportDataJob.java:67)
at batch.spring.example.job.ImportDataJob$$EnhancerBySpringCGLIB$$eb882444.CGLIB$CsvReader$1(<generated>)
at batch.spring.example.job.ImportDataJob$$EnhancerBySpringCGLIB$$eb882444$$FastClassBySpringCGLIB$$6d548885.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:309)
at batch.spring.example.job.ImportDataJob$$EnhancerBySpringCGLIB$$eb882444.CsvReader(<generated>)
at sun.reflect.NativeMethodAccessorImpl.inv [main] INFO org.springframework.context.annotation.AnnotationConfigApplicationContext - Refreshing org.springframework.c[email protected]: startup date [Thu Oct 22 11:26:18 IST 2015]; root of context hierarchy
[main] INFO org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader - Skipping bean definition for [BeanMethod:name=importDataJob,declaringClass=batch.spring.example.job.ImportDataJob]: a definition for bean 'importDataJob' already exists. This top-level bean definition is considered as an override.
[main] WARN org.springframework.context.annotation.ConfigurationClassEnhancer - @Bean method ScopeConfiguration.stepScope is non-static and returns an object assignable to Spring's BeanFactoryPostProcessor interface. This will result in a failure to process annotations such as @Autowired, @Resource and @PostConstruct within the method's declaring @Configuration class. Add the 'static' modifier to this method to avoid these container lifecycle issues; see @Bean javadoc for complete details.
[main] WARN org.springframework.context.annotation.ConfigurationClassEnhancer - @Bean method ScopeConfiguration.jobScope is non-static and returns an object assignable to Spring's BeanFactoryPostProcessor interface. This will result in a failure to process annotations such as @Autowired, @Resource and @PostConstruct within the method's declaring @Configuration class. Add the 'static' modifier to this method to avoid these container lifecycle issues; see @Bean javadoc for complete details.
[main] WARN org.springframework.context.annotation.AnnotationConfigApplicationContext - Exception encountered during context initialization - cancelling refresh attempt
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'CsvReader' defined in batch.spring.example.job.ImportDataJob: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.item.ItemReader]: Factory method 'CsvReader' threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1123)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1018)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:305)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:301)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:196)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
at org.springframework.context.annotation.AnnotationConfigApplicationContext.<init>(AnnotationConfigApplicationContext.java:84)
at batch.spring.example.ImportDataApp.main(ImportDataApp.java:24)
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.item.ItemReader]: Factory method 'CsvReader' threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189)
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588)
... 13 more
Caused by: java.lang.NullPointerException
at batch.spring.example.job.item_reader.CsvReader.<init>(CsvReader.java:28)
at batch.spring.example.job.ImportDataJob.CsvReader(ImportDataJob.java:67)
at batch.spring.example.job.ImportDataJob$$EnhancerBySpringCGLIB$$eb882444.CGLIB$CsvReader$1(<generated>)
at batch.spring.example.job.ImportDataJob$$EnhancerBySpringCGLIB$$eb882444$$FastClassBySpringCGLIB$$6d548885.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:309)
at batch.spring.example.job.ImportDataJob$$EnhancerBySpringCGLIB$$eb882444.CsvReader(<generated>)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162)
... 14 more
Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'CsvReader' defined in batch.spring.example.job.ImportDataJob: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.item.ItemReader]: Factory method 'CsvReader' threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1123)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1018)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:510)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:305)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:301)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:196)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:757)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:480)
at org.springframework.context.annotation.AnnotationConfigApplicationContext.<init>(AnnotationConfigApplicationContext.java:84)
at batch.spring.example.ImportDataApp.main(ImportDataApp.java:24)
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.batch.item.ItemReader]: Factory method 'CsvReader' threw exception; nested exception is java.lang.NullPointerException
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189)
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588)
... 13 more
Caused by: java.lang.NullPointerException
at batch.spring.example.job.item_reader.CsvReader.<init>(CsvReader.java:28)
at batch.spring.example.job.ImportDataJob.CsvReader(ImportDataJob.java:67)
at batch.spring.example.job.ImportDataJob$$EnhancerBySpringCGLIB$$eb882444.CGLIB$CsvReader$1(<generated>)
at batch.spring.example.job.ImportDataJob$$EnhancerBySpringCGLIB$$eb882444$$FastClassBySpringCGLIB$$6d548885.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228)
at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:309)
at batch.spring.example.job.ImportDataJob$$EnhancerBySpringCGLIB$$eb882444.CsvReader(<generated>)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162)
... 14 more
你能和我们分享Environment source和context.xml吗？ –
为什么你在'env.getProperty（“csv.filename”）中有文件名前的文件类型csv''不应该是'env.getProperty（“filename.csv”）'？ –
@AmirAl该属性包含csv文件的文件名。第二个选项会令人困惑，因为它看起来像是一个名为'filename.csv'的文件而不是一个属性。 – Kayaman