[英]Spring Batch How to read multiple table (queries) as Reader and write it as flat file write
In my project I have read multiple tables with different queries and consolidate those results sets in flat files. 在我的项目中,我已经阅读了多个具有不同查询的表,并将这些结果集合并到平面文件中。 How do I achieve that.
我如何实现这一目标。 I mean JdbcReader is directly taking 1 select query, how can I customize it.
我的意思是JdbcReader直接采用1个选择查询,我该如何自定义它。
If JdbcCursorItemReader does not suit your needs, you are always free to implement a custom reader by implementing the ItemReader interface. 如果JdbcCursorItemReader不适合您的需求,您可以通过实现ItemReader接口自由地实现自定义阅读器。
public interface ItemReader<T> {
T read() throws Exception, UnexpectedInputException, ParseException;
}
Just write a class that implements this interface and inject a jdbcTemplate to query multiple tables. 只需编写一个实现此接口的类,并注入一个jdbcTemplate来查询多个表。
public Class MyCompositeJdbcReader implements ItemReader<ConsolidateResult>{
private JdbcTemplate jdbcTemplate;
public ConsolidateResult read()
throws Exception, UnexpectedInputException, ParseException{
ConsolidateResult cr = new ConsolidateResult();
String name= this.jdbcTemplate.queryForObject(
"select name from customer where id = ?",new Object[]{1}, String.class);
String phoneNumber= this.jdbcTemplate.queryForObject(
"select phone from customer_contact where custid = ?",
new Object[]{1},String.class);
cr.setName(name);
cr.setPhone(phoneNumber);
return cr;
}
} }
I did not compile the code but I hope it gives an idea. 我没有编译代码,但我希望它能给出一个想法。
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