iBatis - for beginners

By Anand Gunasekaran - June 28, 2013

iBatis is a Data persistence framework like Hibernate, JDO and EJB that maps objects to SQL statements. It is a lightweight framework and persistence API good for persisting POJOs( Plain OldJava Objects). iBatis is different from Hibernate, JDO since it uses stored procedures and existing SQL to handle database.

In this tutorial we are going to tell you iBatis configuration for a small application to run. As it is hard to explain everything in one go? so we have presented this tutorial into few separate examples. This example is all about to read data from the database and showing the results on your command prompt. In the second example you will learn to add more data into the database and after that third example is going to show you how to delete the data from the records using iBatis.

Now in the first example that is going to show records from the database, we need a database to run queries, so we are using MySQL 5.0 as database for this example.

Here we are retrieving contact information of few persons. Table structure of "Contact" table is as given below:

Creating Database in MySQL

DROP TABLE IF EXISTS `contact`;

CREATE TABLE `contact` (
   `id` int(11) NOT NULL auto_increment,
   `firstName` varchar(20) default NULL,
   `lastName` varchar(20) default NULL,
   `email` varchar(20) default NULL,
   PRIMARY KEY (`id`)
);

According to this table "Contact" we have to make a POJO class. Our example database "vin" has a"Contact" table, which have four fields as:

id
firstName
lastName
email

Contact.java

public class Contact {
  private String firstName;
  private String lastName;
  private String email;
  private int id;

  public Contact() {}

  public Contact(
String firstName,
   String lastName,
   String email) {
  this.firstName = firstName;
  this.lastName = lastName;
  this.email = email;
  }

  public String getEmail() {
  return email;
  }
  public void setEmail(String email) {
  this.email = email;
  }
  public String getFirstName() {
  return firstName;
  }
  public void setFirstName(String firstName) {
  this.firstName = firstName;
  }
  public int getId() {
  return id;
  }
  public void setId(int id) {
  this.id = id;
  }
  public String getLastName() {
  return lastName;
  }
  public void setLastName(String lastName) {
  this.lastName = lastName;
  }
}

For mapping configuration we need to create "SqlMapConfig.xml" which specifies following things:

Namespace prefix for referring mapped statements.
Our database will be accessed using JDBC
JDBC driver for MySQL is "com.mysql.jdbc.Driver"
Connection URL is "jdbc:mysql://192.168.10.112:3306/vin"
username and password is "root" and "root"
Our sql statement mappings are described in "Contact.xml"

SqlMapConfig.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE sqlMapConfig
PUBLIC "-//ibatis.apache.org//DTD SQL Map Config 2.0//EN"
"http://ibatis.apache.org/dtd/sql-map-config-2.dtd">

<sqlMapConfig>
   <settings useStatementNamespaces="true"/>
   <transactionManager type="JDBC">
<dataSource type="SIMPLE">
<property name="JDBC.Driver" value="com.mysql.jdbc.Driver"/>
<property name="JDBC.ConnectionURL"
   value="jdbc:mysql://192.168.10.112:3306/vin"/>
<property name="JDBC.Username" value="root"/>
<property name="JDBC.Password" value="root"/>
</dataSource>
</transactionManager>
   <sqlMap resource="Contact.xml"/>
</sqlMapConfig>

Mapping file "Contact.xml" is given as follows which is responsible for our application to execute SQL queries. Full code of Contact.xml is as follows:

Contact.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE sqlMap
PUBLIC "-//ibatis.apache.org//DTD SQL Map 2.0//EN"
"http://ibatis.apache.org/dtd/sql-map-2.dtd">

<sqlMap namespace="Contact">

<select id="getAll" resultClass="Contact">
select * from contact
</select>
</sqlMap>

Now to show data from database we have created a class "IbatisExample", which reads configuration from SqlMapConfig.xml and then show all data on your console output. Full source code ofIbatisExample.java is as follows:

IbatisExample.java

import com.ibatis.common.resources.Resources;
import com.ibatis.sqlmap.client.SqlMapClient;
import com.ibatis.sqlmap.client.SqlMapClientBuilder;
import java.io.*;
import java.sql.SQLException;
import java.util.*;

public class IbatisExample{
  public static void main(String[] args)
  throws IOException,SQLException{
  Reader reader = Resources.getResourceAsReader("SqlMapConfig.xml");
  SqlMapClient sqlMap =
SqlMapClientBuilder.buildSqlMapClient(reader);
  //Output all contacts
  System.out.println("All Contacts");
  List<Contact> contacts = (List<Contact>)
  sqlMap.queryForList("Contact.getAll",null);
  Contact contact = null;
  for (Contact c : contacts) {
  System.out.print("  " + c.getId());
  System.out.print("  " + c.getFirstName());
  System.out.print("  " + c.getLastName());
  System.out.print("  " + c.getEmail());
  contact = c;
  System.out.println("");
  }
  }
}

To run this example you have to follow these steps :

Create table Contact in your MySQL database
Download jar file of iBatis(ibatis-common-2.jar,ibatis-dao-2.jar,ibatis-sqlmap-2.jar) and put it to your lib directory
Set class path
Create and save Contact.java and compile it
Create and save Contact.xml
now create SqlMapConfig.xml file and finally
create IbatisExample.java and compile it
Execute IbatisExample file

Output:

Output on your command prompt would be like as follows.

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iBatis - for beginners

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