No Map-based equivalent of ListPreparedStatementSetter

[greg.hopkins]

I have done a great deal of CTFI on this matter, so I hope I'm not asking a completely stupid question.

I need a Map-based implementation of PreparedStatementSetter. Since ListPreparedStatementSetter is in the Spring Batch project, I think this forum is the most appropriate place to pose a question. In my experience with the Spring Framework, if I need it - it probably already exists. So that's why I am curious...

Here would be a usage scenario - feel free to correct this scenario as well.

	<bean id="myReader" class="org.springframework.batch.item.database.JdbcCursorItemReader" scope="step">
		<property name="dataSource" ref="myDataSource"/>
		<property name="rowMapper"><bean class="org.springframework.jdbc.core.ColumnMapRowMapper"/></property>
		<property name="sql">
			<bean class="org.apache.commons.io.IOUtils" factory-method="toString">
				<constructor-arg type="java.io.InputStream" value="classpath:/my.sql"/>
			</bean>
		</property>
		<property name="preparedStatementSetter">
			<bean class="my.MapPreparedStatementSetter">
				<property name="parameters">
					<map>
						<entry key="begin" value="#{jobParameters['begin.date']}"/>
						<entry key="end" value="#{jobParameters['end.date']}"/>
					</map>
				</property>
			</bean>
		</property>
	</bean>

I went ahead and implemented a solution, based on the source for ListPreparedStatementSetter - keep in mind this is my first go at it... Be nice!

public class MapPreparedStatementSetter implements PreparedStatementSetter, InitializingBean {
	
    private Map<String, ?> parameters;

    @Override
    public void setValues(PreparedStatement ps) throws SQLException {
		int i=0;
		for (Map.Entry<String, ?> entry : parameters.entrySet()) {
			StatementCreatorUtils.setParameterValue(
					ps,
					++i,
					new SqlParameter(entry.getKey(), StatementCreatorUtils.javaTypeToSqlParameterType(entry.getValue().getClass())),
					entry.getValue()
			);
		}
    }

  
    public void setParameters(Map<String, ?> parameters) {
        this.parameters = parameters;
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        Assert.notNull(parameters, "Parameters must be provided");
    }

}

Lot's of mutable state there - that implementation is NOT thread safe. That will be in version 2.

Is there a different or better way to do this? I see the usage for ListPreparedStatementSetter, but the SQL I have to execute is far too complex to use '?' to bind ordered parameters - it truly needs named parameters.

Thanks!!!

[michael.lange]

afaik there is no NamedParameter Support for JdbcCursorItemReader in Spring Batch yet, but you can wrap a NamedParameterJdbcTemplate dao implementation as itemReader