Spring Batch Example – XML File To CSV File
In this tutorial, we will show you how to configure a Spring Batch job to read XML file (JAXB2
library) into a csv
file, and filter out the record before writing with ItemProcessor
.
Tools and libraries used
- Maven 3
- Eclipse 4.2
- JDK 1.6
- Spring Core 3.2.2.RELEASE
- Spring Batch 2.2.0.RELEASE
- Spring OXM 3.2.2.RELEASE
P.S This example – XML file (reader) – filtering (itemProcessor) – CSV (writer).
1. Simple Java Project
1. Create a quick start Java Project with Maven, converts and imports into Eclipse IDE.
$ mvn archetype:generate -DgroupId=com.mkyong -DartifactId=SpringBatchExample3
-DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false
$ cd SpringBatchExample3/
$ mvn eclipse:eclipse
2. Project Dependencies
Declares all project dependencies in the pom.xml
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0
http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.mkyong</groupId>
<artifactId>SpringBatchExample</artifactId>
<packaging>jar</packaging>
<version>1.0-SNAPSHOT</version>
<name>SpringBatchExample</name>
<url>http://maven.apache.org</url>
<properties>
<jdk.version>1.6</jdk.version>
<spring.version>3.2.2.RELEASE</spring.version>
<spring.batch.version>2.2.0.RELEASE</spring.batch.version>
</properties>
<dependencies>
<!-- Spring Core -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- Spring XML to/back object -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-oxm</artifactId>
<version>${spring.version}</version>
</dependency>
<!-- Spring Batch dependencies -->
<dependency>
<groupId>org.springframework.batch</groupId>
<artifactId>spring-batch-core</artifactId>
<version>${spring.batch.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.batch</groupId>
<artifactId>spring-batch-infrastructure</artifactId>
<version>${spring.batch.version}</version>
</dependency>
</dependencies>
<build>
<finalName>spring-batch</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-eclipse-plugin</artifactId>
<version>2.9</version>
<configuration>
<downloadSources>true</downloadSources>
<downloadJavadocs>false</downloadJavadocs>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>2.3.2</version>
<configuration>
<source>${jdk.version}</source>
<target>${jdk.version}</target>
</configuration>
</plugin>
</plugins>
</build>
</project>
3. Project Directory Structure
Review the final project structure, get an overview what will going on next.
4. XML File
<?xml version="1.0" encoding="UTF-8" ?>
<company>
<record refId="1001">
<name>mkyong</name>
<age>31</age>
<dob>31/8/1982</dob>
<income>200,000</income>
</record>
<record refId="1002">
<name>kkwong</name>
<age>30</age>
<dob>26/7/1983</dob>
<income>100,999</income>
</record>
<record refId="1003">
<name>joel</name>
<age>29</age>
<dob>21/8/1984</dob>
<income>1,000,000</income>
</record>
<record refId="1004">
<name>leeyy</name>
<age>29</age>
<dob>21/3/1984</dob>
<income>80,000.89</income>
</record>
</company>
5. Read XML File
In this example, we use Jaxb2Marshaller
to map XML values and attributes to an object.
<!-- ...... -->
<bean id="xmlItemReader"
class="org.springframework.batch.item.xml.StaxEventItemReader">
<property name="fragmentRootElementName" value="record" />
<property name="resource" value="classpath:xml/report.xml" />
<property name="unmarshaller" ref="reportUnmarshaller" />
</bean>
<!-- Read and map values to object, via jaxb2 -->
<bean id="reportUnmarshaller"
class="org.springframework.oxm.jaxb.Jaxb2Marshaller">
<property name="classesToBeBound">
<list>
<value>com.mkyong.model.Report</value>
</list>
</property>
</bean>
Annotate the Report
to tell which XML value maps to which field.
package com.mkyong.model;
import java.math.BigDecimal;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
import javax.xml.bind.annotation.adapters.XmlJavaTypeAdapter;
import com.mkyong.adapter.JaxbBigDecimalAdapter;
import com.mkyong.adapter.JaxbDateAdapter;
@XmlRootElement(name = "record")
public class Report {
private int refId;
private String name;
private int age;
private Date dob;
private BigDecimal income;
@XmlAttribute(name = "refId")
public int getRefId() {
return refId;
}
public void setRefId(int refId) {
this.refId = refId;
}
@XmlElement(name = "age")
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
@XmlElement
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@XmlJavaTypeAdapter(JaxbDateAdapter.class)
@XmlElement
public Date getDob() {
return dob;
}
public void setDob(Date dob) {
this.dob = dob;
}
@XmlJavaTypeAdapter(JaxbBigDecimalAdapter.class)
@XmlElement
public BigDecimal getIncome() {
return income;
}
public void setIncome(BigDecimal income) {
this.income = income;
}
// for csv file only
public String getCsvDob() {
SimpleDateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");
return dateFormat.format(getDob());
}
}
In JAXB2, those “complex” data type like Date
and BigDecimal
, will not map to the field automatically, even it’s annotated.
To make JAXB2 supports Date
conversion, you need to create a custom Adapter to handle the Date format
manually, then attaches the adapter via @XmlJavaTypeAdapter
.
package com.mkyong.adapter;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.xml.bind.annotation.adapters.XmlAdapter;
public class JaxbDateAdapter extends XmlAdapter<String, Date> {
private SimpleDateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");
@Override
public String marshal(Date date) throws Exception {
return dateFormat.format(date);
}
@Override
public Date unmarshal(String date) throws Exception {
return dateFormat.parse(date);
}
}
Same to BigDecimal
, the commas “,” in the XML’s income element is causing the conversion problem, you need a custom adapter to handle it also.
package com.mkyong.adapter;
import java.math.BigDecimal;
import javax.xml.bind.annotation.adapters.XmlAdapter;
public class JaxbBigDecimalAdapter extends XmlAdapter<String, BigDecimal> {
@Override
public String marshal(BigDecimal obj) throws Exception {
return obj.toString();
}
@Override
public BigDecimal unmarshal(String obj) throws Exception {
return new BigDecimal(obj.replaceAll(",", ""));
}
}
6. Spring Batch Core Setting
Define jobRepository
and jobLauncher
.
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-3.2.xsd">
<!-- stored job-meta in memory -->
<bean id="jobRepository"
class="org.springframework.batch.core.repository.support.MapJobRepositoryFactoryBean">
<property name="transactionManager" ref="transactionManager" />
</bean>
<bean id="transactionManager"
class="org.springframework.batch.support.transaction.ResourcelessTransactionManager" />
<bean id="jobLauncher"
class="org.springframework.batch.core.launch.support.SimpleJobLauncher">
<property name="jobRepository" ref="jobRepository" />
</bean>
</beans>
7. Spring Batch Jobs
A Spring batch job, read the report.xml
file, map it to Report
object, and write it into a csv file. Read the comments, it should be self-explanatory.
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:batch="http://www.springframework.org/schema/batch"
xmlns:task="http://www.springframework.org/schema/task"
xmlns:util="http://www.springframework.org/schema/util"
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
http://www.springframework.org/schema/util
http://www.springframework.org/schema/util/spring-util-3.2.xsd">
<batch:job id="reportJob">
<batch:step id="step1">
<batch:tasklet>
<batch:chunk reader="xmlItemReader"
writer="cvsFileItemWriter" processor="filterReportProcessor"
commit-interval="1">
</batch:chunk>
</batch:tasklet>
</batch:step>
</batch:job>
<!-- Filtering process -->
<bean id="filterReportProcessor" class="com.mkyong.processor.FilterReportProcessor" />
<bean id="xmlItemReader"
class="org.springframework.batch.item.xml.StaxEventItemReader">
<property name="fragmentRootElementName" value="record" />
<property name="resource" value="classpath:xml/report.xml" />
<property name="unmarshaller" ref="reportUnmarshaller" />
</bean>
<!-- Read and map values to object, via jaxb2 -->
<bean id="reportUnmarshaller" class="org.springframework.oxm.jaxb.Jaxb2Marshaller">
<property name="classesToBeBound">
<list>
<value>com.mkyong.model.Report</value>
</list>
</property>
</bean>
<bean id="cvsFileItemWriter" class="org.springframework.batch.item.file.FlatFileItemWriter">
<!-- write to this csv file -->
<property name="resource" value="file:cvs/report.csv" />
<property name="shouldDeleteIfExists" value="true" />
<property name="lineAggregator">
<bean
class="org.springframework.batch.item.file.transform.DelimitedLineAggregator">
<property name="delimiter" value="," />
<property name="fieldExtractor">
<bean
class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor">
<property name="names" value="refId, name, age, csvDob, income" />
</bean>
</property>
</bean>
</property>
</bean>
</beans>
8. Spring Batch – ItemProcessor
In Spring batch, the wired Processor
will be fired before writing to any resources, so, this is the best place to handle any conversion, filtering and business logic. In this example, the Report
object will be ignored (not write to csv file) if its’ age
is equal to 30.
package com.mkyong.processor;
import org.springframework.batch.item.ItemProcessor;
import com.mkyong.model.Report;
//run before writing
public class FilterReportProcessor implements ItemProcessor<Report, Report> {
@Override
public Report process(Report item) throws Exception {
//filter object which age = 30
if(item.getAge()==30){
return null; // null = ignore this object
}
return item;
}
}
9. Run It
The most simplest way to run a batch job.
package com.mkyong;
import org.springframework.batch.core.Job;
import org.springframework.batch.core.JobExecution;
import org.springframework.batch.core.JobParameters;
import org.springframework.batch.core.launch.JobLauncher;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class App {
public static void main(String[] args) {
String[] springConfig =
{
"spring/batch/config/context.xml",
"spring/batch/jobs/job-report.xml"
};
ApplicationContext context =
new ClassPathXmlApplicationContext(springConfig);
JobLauncher jobLauncher = (JobLauncher) context.getBean("jobLauncher");
Job job = (Job) context.getBean("reportJob");
try {
JobExecution execution = jobLauncher.run(job, new JobParameters());
System.out.println("Exit Status : " + execution.getStatus());
} catch (Exception e) {
e.printStackTrace();
}
System.out.println("Done");
}
}
Output. The XML values are inserted into a csv file.
1001,mkyong,31,31/08/1982,200000
1003,joel,29,21/08/1984,1000000
1004,leeyy,29,21/03/1984,80000.89
Great tuto , code works fine for me
If my file name is dynamic, how do i configure to read? Also if i have more than one file, i want to read the first file. Could you please help
I need Csv to Xml could you plz help me
Hi Mkyong, thanks for this tutorial, this helped me a lot 🙂 A quick question, do you have the same example using Spring Boot. I did not want to write all the configuration XMLs, rather use annotations available in Spring Boot. Thanks a lot 🙂
Hi, It is available in the spring.io documentation itself.
Hi,
My input xml element have hyphen in them. (for example a element name like date-of-birth). Java doesnt allow hyphen in variable names. So how should I read this field from the xml in the above code in Report.java as the code expects the java filed name to be exactly same as the xml element name in the above example?
The job execution fails to fragment the xml if i would wire the taskExecutors to the tasklet to the above example as shown below.
.
com.mkyong.model.Report
If i run the job, i am getting the exception as shown below. I know that StaxEventItemReader is not thread safe. Do you have any idea how to achieve the multithreading for StaxEventItemReader using the task executor
SEVERE: Encountered an error executing step step1 in job reportJob
java.lang.NullPointerException
at com.sun.org.apache.xerces.internal.impl.XMLEntityScanner.load(XMLEntityScanner.java:1748)
at com.sun.org.apache.xerces.internal.impl.XMLEntityScanner.scanQName(XMLEntityScanner.java:780)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.scanStartElement(XMLNSDocumentScannerImpl.java:197)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl$NSContentDriver.scanRootElementHook(XMLNSDocumentScannerImpl.java:602)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:3065)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl$PrologDriver.next(XMLDocumentScannerImpl.java:881)
at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:607)
at com.sun.org.apache.xerces.internal.impl.XMLNSDocumentScannerImpl.next(XMLNSDocumentScannerImpl.java:116)
at com.sun.org.apache.xerces.internal.impl.XMLStreamReaderImpl.next(XMLStreamReaderImpl.java:558)
at com.sun.xml.internal.stream.XMLEventReaderImpl.peek(XMLEventReaderImpl.java:275)
at org.springframework.batch.item.xml.stax.DefaultFragmentEventReader.peek(DefaultFragmentEventReader.java:173)
at org.springframework.batch.item.xml.StaxEventItemReader.moveCursorToNextFragment(StaxEventItemReader.java:152)
at org.springframework.batch.item.xml.StaxEventItemReader.doRead(StaxEventItemReader.java:229)
at org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader.read(AbstractItmCountingItemStreamItemReader.java:88)
at org.springframework.batch.core.step.item.SimpleChunkProvider.doRead(SimpleChunkProvider.java:91)
at org.springframework.batch.core.step.item.SimpleChunkProvider.read(SimpleChunkProvider.java:155)
at org.springframework.batch.core.step.item.SimpleChunkProvider$1.doInIteration(SimpleChunkProvider.java:114)
at org.springframework.batch.repeat.support.RepeatTemplate.getNextResult(RepeatTemplate.java:368)
at org.springframework.batch.repeat.support.RepeatTemplate.executeInternal(RepeatTemplate.java:215)
at org.springframework.batch.repeat.support.RepeatTemplate.iterate(RepeatTemplate.java:144)
at org.springframework.batch.core.step.item.SimpleChunkProvider.provide(SimpleChunkProvider.java:108)
at org.springframework.batch.core.step.item.ChunkOrientedTasklet.execute(ChunkOrientedTasklet.java:69
at org.springframework.batch.core.step.tasklet.TaskletStep$ChunkTransactionCallback.doInTransaction(TaskletStep.java:406)
at org.springframework.batch.core.step.tasklet.TaskletStep$ChunkTransactionCallback.doInTransaction(TaskletStep.java:330)
at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:133)
at org.springframework.batch.core.step.tasklet.TaskletStep$2.doInChunkContext(TaskletStep.java:271)
at org.springframework.batch.core.scope.context.StepContextRepeatCallback.doInIteration(StepContextRepeatCallback.java:77)
at org.springframework.batch.repeat.support.TaskExecutorRepeatTemplate$ExecutingRunnable.run(TaskExecutorRepeatTemplate.java:262)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:722)
hi im ishaan ,do u have any idea..
i have csv file contains 10
records..im doing validation for every record value..if even 1 field
value is not format correctly ..i dont want push that record in to my
DB..
here i have csv of 10 records 5 are correctly formatted ..5 are
wrong format..now how can i separate them? for correct 5 records i need
in one item writer class as list then i push in to DB,
for incorrect
data 5 records i need another item writer to push in to another csv
file..this is my requirement..please share ur ideas how to do…if my
idea is wrong please suggest correct way of implementing my requirement.
That’s cool.
Hi All,
I am working on a project where in I need to convert dynamic nested XML to CSV. The XML node names are not standard. The level of nesting may also vary.
Example :
C1
C1
S1
S1
CT1
CT1
CT2
CT2
CT3
CT3
If this is the XML, I want it to be converted to CSV where the node names would become the Header.
Header : CountryId,CountryName,StateId,StateName,CityId,CityName
Data Row1 : C1,C1,S1,S1,CT1,CT1
Data Row2 : C1,C1,S1,S1,CT2,CT2
Data Row3 : C1,C1,S1,S1,CT3,CT3
Please suggest which is the best library to achieve this.
Posting the XML again
C1
C1
S1
S1
CT1
CT1
CT2
CT2
CT3
CT3
Great and simple example, you save me lots of hours.
Thanks for all your examples.
Cheers
Thank you for the great example. The code works. However, I am getting the following error while running the AppTest.java
…
spring/batch/config/database.xml]; nested exception is java.io.FileNotFoundException
…
In AppTest.java, there are extra/missing config references as listed under
@ContextConfiguration(locations = {
“classpath:spring/batch/jobs/job-report.xml”,
“classpath:spring/batch/config/context.xml”,
“classpath:spring/batch/config/database.xml”,
“classpath:spring/batch/config/test-context.xml”})
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {
“classpath:spring/batch/jobs/job-report.xml”,
“classpath:spring/batch/config/context.xml”,
// “classpath:spring/batch/config/database.xml”, <– to comment and it will function
"classpath:spring/batch/config/test-context.xml"})
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hi im ishaan ,do u have any idea..
i have csv file contains 10 records..im doing validation for every record value..if even 1 field value is not format correctly ..i dont want push that record in to my DB..
here i have csv of 10 records 5 are correctly formatted ..5 are wrong format..now how can i separate them? for correct 5 records i need in one item writer class as list then i push in to DB,
for incorrect data 5 records i need another item writer to push in to another csv file..this is my requirement..please share ur ideas how to do…if my idea is wrong please suggest correct way of implementing my requirement.
Thanks in advance