How to get the type of values from a JDBC query? - spring

Question

I have a spring batch job that takes in a user query, executes that query to find the selected items, and then I want to insert those items into another database. The problem is that I have to convert elements like dates from the resulting query to insert them again. How can I tell the type of the values returned from the query?
This is what I use to read the items which works properly.
#Bean("querySelectiveItems")
#StepScope
public JdbcCursorItemReader querySelectiveItems(#Qualifier("selectiveSourceDatabase") DataSource dataSource,
#Value("#{jobExecutionContext[" + EtlConfiguration.JOB_PARM_MIGRATION_CONFIG + "]}") MigrationDefinition migrationDefinition
) {
JdbcCursorItemReader reader = new JdbcCursorItemReader<>();
reader.setSql(migrationDefinition.getMigrations().getTable().getQuery());
reader.setDataSource(dataSource);
reader.setRowMapper(new ColumnMapRowMapper());
log.info("Queried for items");
return reader;
}
The following is what I wrote to write to the destination database. The problem is that the values I have to insert are unknown because they are the result of a user query. For example if there is a datatype in my insert statement I must have a TO_DATE around the date value. Is there a way to do this?
#Component
#Lazy
class InsertSelectedItems implements ItemWriter<Map<String, Object>> {
private MigrationDefinition migrationDefinition;
private JdbcTemplate destinationTemplate;
public void setDestinationTemplate(JdbcTemplate destinationTemplate) {
this.destinationTemplate = destinationTemplate;
}
public void setMigrationDefinition(MigrationDefinition migrationDefinition) {
this.migrationDefinition = migrationDefinition;
}
#Override
public void write(List<? extends Map<String, Object>> items) throws Exception {
ArrayList<String> columns = new ArrayList<>();
ArrayList<String> values = new ArrayList<>();
System.out.println(items);
for (Map<String, Object> map : items) {
for (Map.Entry<String, Object> entry : map.entrySet()) {
columns.add(entry.getKey());
values.add(String.valueOf(entry.getValue()));
}
}
String sql = String.format("%s ( %s ) VALUES ( %s ) ",
migrationDefinition.getMigrations().getTable().getInsert(),
String.join(",", columns),
String.join(",", values));
log.info(sql);
destinationTemplate.update(sql);
}
}