Dinesh on Java

In this tutorial, we will discuss about an application where we see how to configure a Spring Batch job to read CSV file by FlatFileReader library write into a MySQL database, and also we can filter out some of the records of employees which have less salary or under age employee before writing with ItemProcessor.

Tools and libraries used

• Spring Tool Suite (STS)
• JDK 1.6
• Spring Core 3.2.2.RELEASE
• Spring OXM 3.2.2.RELEASE
• Spring Batch 2.2.0.RELEASE
• MySQL Java Driver 5.1.25

Sample Example of Spring Batch CSV To MySQL Database-

1. Project Directory Structure

2. Input CSV File
employees.csv

1111,ATUL KUMAR,17,300000.0,delhi
3333,ASHUTOSH RAJPUT,21,400000.0,delhi
4444,Adesh Verma,27,80000.0,Kanpur
5555,Dinesh Rajput,37,300000.0,Noida
2222,ATUL KUMAR,17,300000.0,delhi
6666,ASHUTOSH RAJPUT,21,400000.0,delhi
7777,Adesh Verma,27,80000.0,Kanpur
8888,Dinesh Rajput,37,300000.0,Noida

3. ItemReader for CSV Flat File reader

<bean id="employee" class="com.doj.batch.bean.Employee" scope="prototype"></bean>
 
 <bean id="cvsItemReader" class="org.springframework.batch.item.file.FlatFileItemReader">
  <!-- Read a csv file -->
  <property name="resource" value="classpath:csv/employees.csv" />
  <property name="lineMapper">
   <bean class="org.springframework.batch.item.file.mapping.DefaultLineMapper">
     <!-- split it -->
     <property name="lineTokenizer">
         <bean class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer">
       <property name="names" value="empid,name,age,salary,address" />
     </bean>
     </property>
     <property name="fieldSetMapper">   
      <!-- map to an object -->
      <bean class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper">
     <property name="prototypeBeanName" value="employee" />
      </bean>   
     </property>
     </bean>
    </property>
     </bean>
  

Employee.java

package com.doj.batch.bean;


/**
 * @author Dinesh Rajput
 *
 */
public class Employee {
 private int empid;
 private String name;
 private int age;
 private float salary;
 private String address;
 /**
  * @return the empid
  */
 public int getEmpid() {
  return empid;
 }
 /**
  * @param empid the empid to set
  */
 public void setEmpid(int empid) {
  this.empid = empid;
 }
 /**
  * @return the name
  */
 public String getName() {
  return name;
 }
 /**
  * @param name the name to set
  */
 public void setName(String name) {
  this.name = name;
 }
 /**
  * @return the age
  */
 public int getAge() {
  return age;
 }
 /**
  * @param age the age to set
  */
 public void setAge(int age) {
  this.age = age;
 }
 /**
  * @return the salary
  */
 public float getSalary() {
  return salary;
 }
 /**
  * @param salary the salary to set
  */
 public void setSalary(float salary) {
  this.salary = salary;
 }
 /**
  * @return the address
  */
 public String getAddress() {
  return address;
 }
 /**
  * @param address the address to set
  */
 public void setAddress(String address) {
  this.address = address;
 }
 
}

4. Database configuration
ApplicationDB.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
 xmlns:jdbc="http://www.springframework.org/schema/jdbc" 
 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-4.0.xsd
  http://www.springframework.org/schema/jdbc 
  http://www.springframework.org/schema/jdbc/spring-jdbc-4.0.xsd">
 
        <!-- connect to database -->
 <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
  <property name="driverClassName" value="com.mysql.jdbc.Driver" />
  <property name="url" value="jdbc:mysql://localhost:3306/DAVDB" />
  <property name="username" value="root" />
  <property name="password" value="root" />
 </bean>
 
 <bean id="transactionManager" class="org.springframework.batch.support.transaction.ResourcelessTransactionManager" />
 
</beans>

5. Spring Batch Core configuration

Define jobRepository and jobLauncher.
applicationContext.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
 xmlns:context="http://www.springframework.org/schema/context"
 xmlns:p="http://www.springframework.org/schema/p" 
 xmlns:mvc="http://www.springframework.org/schema/mvc" 
 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-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd">

 <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>
 
    <bean id="jobRepository" class="org.springframework.batch.core.repository.support.MapJobRepositoryFactoryBean">
        <property name="transactionManager" ref="transactionManager"/>
    </bean>
 
    <bean id="simpleJob" class="org.springframework.batch.core.job.SimpleJob" abstract="true">
        <property name="jobRepository" ref="jobRepository" />
    </bean>
 
</beans>

6. Spring Batch Jobs Configuration file
simple-job.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
 xmlns:context="http://www.springframework.org/schema/context"
 xmlns:p="http://www.springframework.org/schema/p" 
 xmlns:batch="http://www.springframework.org/schema/batch"
 xmlns:mvc="http://www.springframework.org/schema/mvc" 
 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-4.0.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context-4.0.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc-4.0.xsd
http://www.springframework.org/schema/batch 
http://www.springframework.org/schema/batch/spring-batch-2.0.xsd">

 <import resource="applicationContext.xml"/>
 <import resource="ApplicationDB.xml"/>
 
 <bean id="employee" class="com.doj.batch.bean.Employee" scope="prototype"></bean>
 
 <bean id="cvsItemReader" class="org.springframework.batch.item.file.FlatFileItemReader">
  <!-- Read a csv file -->
  <property name="resource" value="classpath:csv/employees.csv" />
  <property name="lineMapper">
   <bean class="org.springframework.batch.item.file.mapping.DefaultLineMapper">
     <!-- split it -->
     <property name="lineTokenizer">
         <bean class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer">
       <property name="names" value="empid,name,age,salary,address" />
     </bean>
     </property>
     <property name="fieldSetMapper">   
      <!-- map to an object -->
      <bean class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper">
     <property name="prototypeBeanName" value="employee" />
      </bean>   
     </property>
     </bean>
    </property>
     </bean>
  
  <bean id="databaseItemWriter" class="org.springframework.batch.item.database.JdbcBatchItemWriter">
  <property name="dataSource" ref="dataSource" />
  <property name="sql">
    <value>
            <![CDATA[        
              insert into EMPLOYEET(empname,empAge,salary,empaddress) values (:name,:age,:salary,:address)
             ]]>
    </value>
  </property>
  <!-- It will take care matching between object property and sql name parameter -->
  <property name="itemSqlParameterSourceProvider">
   <bean class="org.springframework.batch.item.database.BeanPropertyItemSqlParameterSourceProvider" />
  </property>
    </bean>
    
    <batch:job id="simpleDojJob" job-repository="jobRepository" parent="simpleJob">
     <batch:step id="step1">
      <batch:tasklet transaction-manager="transactionManager">
       <batch:chunk reader="cvsItemReader" writer="databaseItemWriter" commit-interval="2"/>
      </batch:tasklet>
     </batch:step>
    </batch:job>   
</beans>

This is the main xml file to configure the Spring batch job. This simple-job.xml file define a job to read a employees.csv file, match it to employee plain pojo and write the data into MySQL database Employeet table.

7. Spring Batch ItemProcessor for filter data

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, we will be ignored all employees whose have salaried less than 70000 i.e. not write to database as well as ignored those employee whose age less than 22 years.

DataFilterProcessor.java

package com.doj.batch.processor;

import org.springframework.batch.item.ItemProcessor;

import com.doj.batch.bean.Employee;

/**
 * @author Dinesh Rajput
 *
 */
public class DataFilterProcessor implements ItemProcessor<Employee, Employee> {

 @Override
 public Employee process(Employee emp) throws Exception {
  if(emp.getSalary() > 70000.0 && emp.getAge() > 22){
   return emp;
  }else{
   return null;
  }
 }

}

8. Launching Batch Job-

Spring Batch comes with a simple utility class called CommandLineJobRunner which has a main() method which accepts two arguments. First argument is the spring application context file containing job definition and the second is the name of the job to be executed.

Now run as a java application with both two arguments.
org.springframework.batch.core.launch.support.CommandLineJobRunner
simple-job.xml simpleDojJob

Output. The Spring Batch metadata tables are created, and the content of employees.cvs is inserted into database table “EMPLOYEET”.