Spring batch read from xml file and write to Database. need step1 auto generated key for step2 - mysql

Question

As seen in below code in step1 I'm reading users.xml and writing to database now in step2 I'm reading from userdetails.xml and writing to database but I need step1 auto generated key of tbl_user for step2. How Can I do that?
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:batch="http://www.springframework.org/schema/batch"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/batch
http://www.springframework.org/schema/batch/spring-batch-2.2.xsd
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd">
<import resource="../config/context.xml" />
<import resource="../config/database.xml" />
<bean id="xmlItemReader1" class="org.springframework.batch.item.xml.StaxEventItemReader">
<property name="resource" value="file:xml/outputs/users.xml" />
<property name="fragmentRootElementName" value="user" />
<property name="unmarshaller" ref="userUnmarshaller"/>
</bean>
<bean id="xmlItemReader2" class="org.springframework.batch.item.xml.StaxEventItemReader">
<property name="resource" value="file:xml/outputs/userdetails.xml" />
<property name="fragmentRootElementName" value="userdetail" />
<property name="unmarshaller" ref="userUnmarshaller"/>
</bean>
<bean id="itemProcessor1" class="com.qmetry.recovery.mapper.UserItemProcessor" />
<bean id="itemProcessor2" class="com.qmetry.recovery.mapper.UserDetailItemProcessor" />
<job id="testJob2" xmlns="http://www.springframework.org/schema/batch">
<step id="step2_1">
<tasklet transaction-manager="transactionManager">
<chunk reader="xmlItemReader1" writer="databaseItemWriter1" processor="itemProcessor1"
commit-interval="100" />
</tasklet>
<listeners>
<listener ref="testListener" />
</listeners>
</step>
<step id="step2_2">
<tasklet transaction-manager="transactionManager">
<chunk reader="xmlItemReader2" writer="databaseItemWriter2" processor="itemProcessor1"
commit-interval="100" />
</tasklet>
</step>
</job>
<bean id="testListener" class="com.qmetry.recovery.mapper.TestListener" scope="step" />
<bean id="databaseItemWriter1" class="org.springframework.batch.item.database.JdbcBatchItemWriter">
<property name="dataSource" ref="dataSource" />
<property name="sql">
<value>
<![CDATA[
insert into TBL_USER(USERNAME,EMAILID)
values (?, ?)
]]>
</value>
</property>
<!--We need a custom setter to handle the conversion between Jodatime LocalDate and MySQL DATE BeanPropertyItemSqlParameterSourceProvider-->
<property name="itemPreparedStatementSetter">
<bean class="com.qmetry.recovery.mapper.UserItemPreparedStatementSetter"/>
</property>
</bean>
<bean id="databaseItemWriter2" class="org.springframework.batch.item.database.JdbcBatchItemWriter">
<property name="dataSource" ref="dataSource" />
<property name="sql">
<value>
<![CDATA[
insert into TBL_USERDETAIL(USERID,CONTACT)
values (?, ?)
]]>
</value>
</property>
<!--We need a custom setter to handle the conversion between Jodatime LocalDate and MySQL DATE BeanPropertyItemSqlParameterSourceProvider-->
<property name="itemPreparedStatementSetter">
<bean class="com.qmetry.recovery.mapper.UserDetailItemPreparedStatementSetter"/>
</property>
</bean>
users.xml
<?xml version="1.0" encoding="UTF-8"?><users>
<user>
<userId>1</userId>
<userName>Taher</userName>
<emailId>taher.tinwala#hotmail.com</emailId>
</user>
</users>
userdetails.xml
<?xml version="1.0" encoding="UTF-8"?><userdetails>
<userdetail>
<userDetailId>1</userDetailId>
<userId__TblUser>1</userId__TblUser>
<contact>1111111111</contact>
</userdetail>
<userdetail>
<userDetailId>2</userDetailId>
<userId__TblUser>1</userId__TblUser>
<contact>2222222222</contact>
</userdetail>
<userdetail>
<userDetailId>4</userDetailId>
<userId__TblUser>1</userId__TblUser>
<contact>4444444444</contact>
</userdetail>
</userdetails>

Answer 1

You need to pass data to a future step. For explantory documentation see http://docs.spring.io/spring-batch/trunk/reference/html/patterns.html#passingDataToFutureSteps
I have implemented the example from the documentation and adjusted it to your configuration with some assumptions here and there.
During the read (or the write, it depends when you get the data that you want to pass) in step 1 you need to store the data in the StepExecution. Add to your xmlItemReader the following:
public class YourItemReader implements ItemReader<Object>
private StepExecution stepExecution;
public void read(Object item) throws Exception {
// ...
ExecutionContext stepContext = this.stepExecution.getExecutionContext();
stepContext.put("tbl_user", someObject);
}
#BeforeStep
public void saveStepExecution(StepExecution stepExecution) {
this.stepExecution = stepExecution;
}
Your xml will look like this:
<step id="step2_1">
<tasklet transaction-manager="transactionManager">
<chunk reader="xmlItemReader1" writer="databaseItemWriter1" processor="itemProcessor1" commit-interval="100" />
</tasklet>
<listeners>
<listener ref="testListener" />
<listener ref="promotionListener"/>
</listeners>
</step>
Add the promotionListener bean:
<beans:bean id="promotionListener" class="org.springframework.batch.core.listener.ExecutionContextPromotionListener">
<beans:property name="keys" value="tbl_key"/>
</beans:bean>
And finally you need to retrieve the value in step 2. Again asuming you need it in the reader of step 2 you reader in step 2 needs the following code added:
public class YourItemReader2 implements ItemReader<Object>
private Object someObject;
#BeforeStep
public void retrieveInterstepData(StepExecution stepExecution) {
JobExecution jobExecution = stepExecution.getJobExecution();
ExecutionContext jobContext = jobExecution.getExecutionContext();
this.someObject = jobContext.get("tbl_key");
}
Now you have acces to the value read in step 1.
EDIT - adding some example configuration for an extra read step:
After step 1 add a simple step 2 with the following reader to get the new value from the database
<bean id="itemReader" class="org.springframework.batch.item.database.JdbcCursorItemReader"
scope="step">
<property name="dataSource" ref="dataSource" />
<property name="sql">
<value>
<![CDATA[
YOUR SELECT STATEMENT
]]>
</value>
</property>
<property name="rowMapper" ref="rowMapper" />
</bean>
And a simple rowMapper bean
<bean id="rowMapper" class="exampleRowMapper" />
You will have to write your exampleRowMapper obviously to reflect the data your fetching. For example:
public class ExampleRowMapper implements ParameterizedRowMapper<String> {
#Override
public String mapRow(ResultSet rs, int rowNum) throws SQLException {
return String.valueOf(rs.getString(1));
}
}
In your dummywriter you add the stepexecution and you will store your value in the step execution context.:
public class DummyItemWriter implements ItemWriter<Object> {
private StepExecution stepExecution;
#Override
public void write(List<? extends Object> item) throws Exception {
ExecutionContext stepContext = this.stepExecution.getExecutionContext();
stepContext.put("someKey", someObject);
}
}
And the bean for the writer:
<bean id="savingDummyWriter" class="your.package.DummyItemWriter" />
And wrap the reader and writer in a step.
<step id="step2">
<tasklet>
<chunk reader="itemReader" writer="dummyItemWriter" commit-interval="1" />
</tasklet>
<listeners>
<listener ref="promotionListener"/>
</listeners>
</step>