我的工作总是空的。无法使用 Spring Batch 注入批处理作业。为什么？

Question

我正在使用 Spring Batch 来实现批处理作业，但由于某些原因，当我尝试开始我的工作时，我的工作总是为空。在我看来，我的工作没有在 Spring 框架需要时注入。 有人可以告诉我我做错了什么吗？！我有点厌倦了尝试和错误......

这是我的 spring 配置（批量配置）：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:batch="http://www.springframework.org/schema/batch" xmlns:task="http://www.springframework.org/schema/task"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans 
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd 
http://www.springframework.org/schema/task
http://www.springframework.org/schema/task/spring-task-3.2.xsd
http://www.springframework.org/schema/batch
http://www.springframework.org/schema/batch/spring-batch-2.2.xsd">

<bean id="batchTransactionManager"
    class="org.springframework.batch.support.transaction.ResourcelessTransactionManager" />
<bean id="recordItemReader" class="com.blang.court.exports.RecordItemReader" />

<batch:job id="recordReadJob" job-repository="jobRepository">
    <batch:step id="recordReadStep">
        <batch:tasklet ref="recordItemReader"
            transaction-manager="batchTransactionManager" />
    </batch:step>
</batch:job>

<bean id="batchLauncher" class="com.blang.court.exports.BatchLauncher">
    <property name="jobLauncher" ref="jobLauncher" />
    <property name="job" ref="recordReadJob" />
</bean>

还有另一个 Spring 配置（应用程序上下文）：

 <?xml version="1.0" encoding="UTF-8"?>
 <beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ws="http://jax-ws.dev.java.net/spring/core"
xmlns:wss="http://jax-ws.dev.java.net/spring/servlet" xmlns:tx="http://www.springframework.org/schema/tx"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:jee="http://www.springframework.org/schema/jee"

xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
http://jax-ws.dev.java.net/spring/core
http://jax-ws.dev.java.net/spring/core.xsd
http://jax-ws.dev.java.net/spring/servlet
http://jax-ws.dev.java.net/spring/servlet.xsd
http://www.springframework.org/schema/tx 
http://www.springframework.org/schema/tx/spring-tx.xsd
http://www.springframework.org/schema/context 
http://www.springframework.org/schema/context/spring-context-3.1.xsd
http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-3.2.xsd"
default-autowire="byName">

<context:annotation-config />

<tx:annotation-driven transaction-manager="applicationTransactionManager" />


<!-- Mail -->
<bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
    <property name="host" value="localhost" />
</bean>


<!-- JPA -->
<bean id="entityManagerFactory"
    class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
    <property name="persistenceUnitName" value="appPersistenceUnit" />
</bean>

<bean id="applicationTransactionManager" class="org.springframework.orm.jpa.JpaTransactionManager">
    <property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>


<!-- Spring Batch -->
<!-- <bean id="batchTransactionManager" 
    class="org.springframework.batch.support.transaction.ResourcelessTransactionManager" />-->

<bean id="jobRepository"
    class="org.springframework.batch.core.repository.support.MapJobRepositoryFactoryBean">
    <property name="transactionManager" ref="applicationTransactionManager" />
</bean>

<bean id="jobLauncher"
    class="org.springframework.batch.core.launch.support.SimpleJobLauncher">
    <property name="jobRepository" ref="jobRepository" />
</bean>

关于配置。在下一步中，我实现了批处理启动器类。看起来像这样：

import org.springframework.batch.core.Job;
import org.springframework.batch.core.JobExecution;
import org.springframework.batch.core.JobParametersBuilder;
import org.springframework.batch.core.JobParametersInvalidException;
import org.springframework.batch.core.launch.JobLauncher;
import org.springframework.batch.core.repository.JobExecutionAlreadyRunningException;
import org.springframework.batch.core.repository.JobInstanceAlreadyCompleteException;
import org.springframework.batch.core.repository.JobRestartException;

public class BatchLauncher
{
  private Job job;
  private JobLauncher jobLauncher;

  public void launch()
  {
  JobParametersBuilder builder = new JobParametersBuilder();

  try
  {
    JobExecution execution = jobLauncher.run(job, builder.toJobParameters());
  }
  catch (JobExecutionAlreadyRunningException | JobRestartException
          | JobInstanceAlreadyCompleteException
          | JobParametersInvalidException e)
  {
    e.printStackTrace();
  }

 }

 public Job getJob()
 {
   return job;
 }

 public void setJob(Job job)
 {
   this.job = job;
 }

 public JobLauncher getJobLauncher()
 {
    return jobLauncher;
 }

 public void setJobLauncher(JobLauncher jobLauncher)
 {
   this.jobLauncher = jobLauncher;
 }
}

最后是我的工作：

import org.springframework.batch.core.StepContribution;
import org.springframework.batch.core.scope.context.ChunkContext;
import org.springframework.batch.core.step.tasklet.Tasklet;
import org.springframework.batch.repeat.RepeatStatus;
import org.springframework.beans.factory.annotation.Autowired;

import com.blang.court.RecordForm;
import com.blang.court.interfaces.IRecordService;

public class RecordItemReader implements Tasklet
{
   @Autowired
   IRecordService recordService;

   @Override
   public RepeatStatus execute(StepContribution arg0, ChunkContext arg1)
      throws Exception
   {
      recordService.filterRecords(new RecordForm());
      System.out.println("Hi, the job is running! Yeah, finally got it!");
      return RepeatStatus.FINISHED;
   }
 }

我总是在批处理启动器类的这一行上得到一个nullPointerException：

JobExecution execution = jobLauncher.run(job, builder.toJobParameters());

这告诉我我的 jo 是空的。我已经对其进行了调试以证明它......是的，由于某种原因，这项工作是空的......

请帮帮我... :-(

亲切的问候

Answer 1

在您的配置中，job 属性指的是一个 Tasklet 而不是一个 Job..

试试这个配置

<bean id="batchLauncher" class="com.blang.court.exports.BatchLauncher">
    <property name="jobLauncher" ref="jobLauncher" />
    <property name="job" ref="recordReadJob" />
</bean>

希望对你有帮助

---

当你通过 new 创建对象时，autowire\inject 不起作用...

示例类

public class Test {
    public static void main(String[] args) {
        ApplicationContext context=new ClassPathXmlApplicationContext("app-context.xml");
        BatchLauncher batchLauncher = (BatchLauncher ) context.getBean("batchLauncher");
        batchLauncher.launch();
    }
} 

这个link解决了同样的问题