Spring批处理 jobParameters的值为null

huangapple
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英文:

Spring batch jobParameters value null

问题

在一个Spring批处理中，我试图传递jobParameters并在我的JdbcCursorItemReader中使用它们。下面是相关的一部分代码：

  1. @Configuration
  2. public class SpringBatchConfig extends DefaultBatchConfigurer{
  4.     private String demoVar;
  6.     public String getDemoVar() {
  7.         return demoVar;
  8.     }
  10.     public void setDemoVar(@Value("#{jobParameters['demoVarValue']}") String demoVar) {
  11.         this.demoVar = demoVar;
  12.     }
  14.     @Bean
  15.     @StepScope
  16.     public JdbcCursorItemReader<User> reader1() {
  17.         String sqlQuery = String.format("select * FROM TABLE_NAME where demoVar=? ");
  18.         System.out.println(demoVar);
  19.         JdbcCursorItemReader<User> cursorItemReader = new JdbcCursorItemReader<>();
  20.         cursorItemReader.setDataSource(dataSource);
  21.         cursorItemReader.setSql(sqlQuery);
  22.         cursorItemReader.setPreparedStatementSetter(new PreparedStatementSetter() {
  23.             public void setValues(PreparedStatement preparedStatement) throws SQLException {
  24.                 preparedStatement.setString(1, demoVar);
  25.             }
  26.         });
  27.         cursorItemReader.setRowMapper(new DbRowMapper());
  28.         return cursorItemReader;
  29.     }
  30. ...

控制器类（包含作业启动器）：

  1. @RestController
  2. @RequestMapping("/load")
  3. public class LoadController {
  5.     @Autowired
  6.     JobLauncher jobLauncher;
  8.     @Autowired
  9.     Job job;
  11.     @GetMapping("/users")
  12.     public BatchStatus load() throws JobParametersInvalidException, JobExecutionAlreadyRunningException, JobRestartException, JobInstanceAlreadyCompleteException {
  13.         
  14.         JobParameters jobParameters = new JobParametersBuilder()
  15.                                     .addString("demoVarValue", "001")
  16.                                     .toJobParameters();
  17.         
  18.         JobExecution jobExecution = jobLauncher.run(job, jobParameters);
  20.         System.out.println("JobExecution: " + jobExecution.getStatus());
  22.         return jobExecution.getStatus();
  23.     }
  24. }

但是在readerbean中，从jobParameters解析出的demoVar值传递为null，而不是预期的001。

英文:

In a spring batch, I'm trying to pass jobParameters and use them in my JdbcCursorItemReader. A snippet from the same is:

  1. @Configuration
  2. public class SpringBatchConfig extends DefaultBatchConfigurer{
  4.     private String demoVar;
  6. 	public String getDemoVar() {
  7. 		return demoVar;
  8. 	}
  10. 	public void setDemoVar(@Value(&quot;#{jobParameters[&#39;demoVarValue&#39;]}&quot;) String demoVar) {
  11. 		this.demoVar = demoVar;
  12. 	}
  14.     @Bean
  15. 	@StepScope
  16. 	public JdbcCursorItemReader&lt;User&gt; reader1() {
  17. 		String sqlQuery = String.format(&quot;select * FROM TABLE_NAME where demoVar=? &quot;);
  18. 		System.out.println(demoVar);
  19. 		JdbcCursorItemReader&lt;User&gt; cursorItemReader = new JdbcCursorItemReader&lt;&gt;();
  20. 		cursorItemReader.setDataSource(dataSource);
  21. 		cursorItemReader.setSql(sqlQuery);
  22. 		cursorItemReader.setPreparedStatementSetter(new PreparedStatementSetter() {
  23. 		   public void setValues(PreparedStatement preparedStatement) throws SQLException {
  24. 		      preparedStatement.setString(1, demoVar);
  25. 		   }
  26. 		});
  27. 		cursorItemReader.setRowMapper(new DbRowMapper());
  28. 		return cursorItemReader;
  29. 	}
  30. ...

Controller class(containing job launcher):

  1. @RestController
  2. @RequestMapping(&quot;/load&quot;)
  3. public class LoadController {
  5.     @Autowired
  6.     JobLauncher jobLauncher;
  8.     @Autowired
  9.     Job job;
  11.     @GetMapping(&quot;/users&quot;)
  12.     public BatchStatus load() throws JobParametersInvalidException, JobExecutionAlreadyRunningException, JobRestartException, JobInstanceAlreadyCompleteException {
  13.         
  14.         JobParameters jobParameters = new JobParametersBuilder()
  15.         							.addString(&quot;demoVarValue&quot;, &quot;001&quot;)
  16.         							.toJobParameters();
  17.         
  18.         JobExecution jobExecution = jobLauncher.run(job, jobParameters);
  20.         System.out.println(&quot;JobExecution: &quot; + jobExecution.getStatus());
  22.         return jobExecution.getStatus();
  23.     }
  24. }

But in the reader bean, the value of the demoVar parsed from jobParameters is being passed as null instead of the expected 001.

答案1

得分: 3

  1. 除非在其他地方调用了getter方法，否则您不需要`demoVar`字段。您可以将其作为reader的bean定义方法的参数传递：
  3. @Bean
  4. @StepScope
  5. public JdbcCursorItemReader<User> reader1(@Value("#{jobParameters['demoVarValue']}") String demoVar) {
  6.     String sqlQuery = String.format("select * FROM TABLE_NAME where demoVar=? ");
  7.     System.out.println(demoVar);
  8.     JdbcCursorItemReader<User> cursorItemReader = new JdbcCursorItemReader<>();
  9.     cursorItemReader.setDataSource(dataSource);
  10.     cursorItemReader.setSql(sqlQuery);
  11.     cursorItemReader.setPreparedStatementSetter(new PreparedStatementSetter() {
  12.        public void setValues(PreparedStatement preparedStatement) throws SQLException {
  13.           preparedStatement.setString(1, demoVar);
  14.        }
  15.     });
  16.     cursorItemReader.setRowMapper(new DbRowMapper());
  17.     return cursorItemReader;
  18. }
  20. 作业参数的延迟绑定在参考文档的[作业和步骤属性的延迟绑定](https://docs.spring.io/spring-batch/docs/4.2.x/reference/html/step.html#late-binding)部分进行了解释。
英文:

You don't need the demoVar field (unless you are calling the getter somewhere else). You can pass it as a parameter of reader's bean definition method:

  1. @Bean
  2. @StepScope
  3. public JdbcCursorItemReader&lt;User&gt; reader1(@Value(&quot;#{jobParameters[&#39;demoVarValue&#39;]}&quot;) String demoVar) {
  4.     String sqlQuery = String.format(&quot;select * FROM TABLE_NAME where demoVar=? &quot;);
  5.     System.out.println(demoVar);
  6.     JdbcCursorItemReader&lt;User&gt; cursorItemReader = new JdbcCursorItemReader&lt;&gt;();
  7.     cursorItemReader.setDataSource(dataSource);
  8.     cursorItemReader.setSql(sqlQuery);
  9.     cursorItemReader.setPreparedStatementSetter(new PreparedStatementSetter() {
  10.        public void setValues(PreparedStatement preparedStatement) throws SQLException {
  11.           preparedStatement.setString(1, demoVar);
  12.        }
  13.     });
  14.     cursorItemReader.setRowMapper(new DbRowMapper());
  15.     return cursorItemReader;
  16. }

Late binding of job parameters is explained in the Late Binding of Job and Step Attributes section of the reference documentation.

huangapple
  • 本文由 发表于 2020年10月5日 19:35:25
  • 转载请务必保留本文链接：https://go.coder-hub.com/64207827.html
  • java
  • spring
  • spring-batch
  • spring-boot
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