Question

i’m trying to pass a parameter to my query in spring batch. I decided to create a tasklet and use JdbcTemplate as follows …

public RepeatStatus execute(StepContribution stepContribution, ChunkContext chunkContext)
        throws EpsilonBatchBusinessException {

    LOGGER.debug("Enter execute.");

    JdbcTemplate jdbcTemplate = new JdbcTemplate(dataSource);

    jdbcTemplate.query(queryString,
        new PreparedStatementSetter() {
            public void setValues(PreparedStatement preparedStatement) throws SQLException {
                preparedStatement.setInt(1, runNumber);
            }
        },
        rowMapper);

    LOGGER.debug("Exit execute.");

    return RepeatStatus.FINISHED;
}

So am injecting to this bean a dataSource, queryString, rowMapper object, and the parameter (runNumber) .. This tasklet will be called within a step to create a list. I usually pass the row mapper to JdbcCursorItemReader spring bean and wouldn’t write a tasklet, but my query string needs a parameter hence am writing this tasklet. Am just not sure if this tasklet will do the trick as with JdbcCursorItemReader? Your input wil be appreciated

Answer 1

A better option would be to use the JdbcCursorItemReader and write a custom PreparedStatementSetter.

The PreparedStatementSetter interface is very simple; pretty much all the code you’d need to write is below. Once the setter is written, all you need to do is configure it as a new bean with the runNumber value injected in the config, and then inject that bean into a JdbcCursorItemReader. This allows you to use all the usual ItemReaders and ItemWriters instead of having to implement everything by hand in a Tasklet.

package com.foo;

import java.sql.PreparedStatement;
import java.sql.SQLException;

import org.springframework.jdbc.core.PreparedStatementSetter;


public class YourParamSetter implements PreparedStatementSetter {


    private int runNumber;

    public void setValues(PreparedStatement ps) throws SQLException {

        ps.setInt(1, runNumber);

    }

    public void setRunNumber(int runNumber) {
        this.runNumber = runNumber;
    }

    public int getRunNumber() {
        return runNumber;
    }

}