Java + myBatis + MySql

Connecting to MySQL from Java application using myBatis.

Objective

• How to connect to MySQL database from Java application using myBatis?
• How to use MyBatis config & mapper using XML?

Environment

Eclipse (Indigo)

Libraries

-mySql java connector (jar)
- myBatis 3.1.1

( 1 ) Database

( 2 ) Java Project

• Create new Java Project
• Add new folder “lib”
• Copy mysql-connector-java (jar) and myBatis to “lib” folder
• Add jars file to java build path

( 3 ) Java Classes

Person.javaPersonDAO.javaMyBatisConnectionFactory.javaMain.java

Person.java

package com.hmkcode.vo;public class Person  {    private int id;    private String name;    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String toString(){        return "id: "+id+" Name: "+name;    }}

PersonDAO.java

package com.hmkcode.dao;import java.util.List;import org.apache.ibatis.session.SqlSession;import org.apache.ibatis.session.SqlSessionFactory;import com.hmkcode.vo.Person;public class PersonDAO {    private SqlSessionFactory sqlSessionFactory = null;    public PersonDAO(SqlSessionFactory sqlSessionFactory){        this.sqlSessionFactory = sqlSessionFactory;    }    /**     * Returns the list of all Person instances from the database.     * @return the list of all Person instances from the database.     */    @SuppressWarnings("unchecked")    public  List<Person> selectAll(){        List<Person> list = null;        SqlSession session = sqlSessionFactory.openSession();        try {            list = session.selectList("Person.selectAll");        } finally {            session.close();        }        System.out.println("selectAll() --> "+list);        return list;    }    /**     * Select instance of Person from the database.     * @param person the instance to be persisted.     */   public Person selectById(int id){        Person person = null;        SqlSession session = sqlSessionFactory.openSession();        try {            person = session.selectOne("Person.selectById", id);        } finally {            session.close();        }        System.out.println("selectById("+id+") --> "+person);        return person;    }     /**     * Insert an instance of Person into the database.     * @param person the instance to be persisted.     */   public int insert(Person person){       int id = -1;        SqlSession session = sqlSessionFactory.openSession();        try {            id = session.insert("Person.insert", person);        } finally {            session.commit();            session.close();        }        System.out.println("insert("+person+") --> "+person.getId());        return id;    }    /**   * Update an instance of Person into the database.   * @param person the instance to be persisted.   */    public void update(Person person){       int id = -1;      SqlSession session = sqlSessionFactory.openSession();      try {          id = session.update("Person.update", person);      } finally {          session.commit();          session.close();      }      System.out.println("update("+person+") --> updated");  }    /**     * Delete an instance of Person from the database.     * @param id value of the instance to be deleted.     */    public void delete(int id){        SqlSession session = sqlSessionFactory.openSession();        try {            session.delete("Person.delete", id);        } finally {            session.commit();            session.close();        }        System.out.println("delete("+id+")");    }}

MyBatisConnectionFactory.java

package com.hmkcode.mybatis;import java.io.FileNotFoundException;import java.io.IOException;import java.io.Reader;import org.apache.ibatis.io.Resources;import org.apache.ibatis.session.SqlSessionFactory;import org.apache.ibatis.session.SqlSessionFactoryBuilder;public class MyBatisConnectionFactory {    private static SqlSessionFactory sqlSessionFactory;    static {        try {            String resource = "com/hmkcode/mybatis/config.xml";            Reader reader = Resources.getResourceAsReader(resource);            if (sqlSessionFactory == null) {                sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);            }        }        catch (FileNotFoundException fileNotFoundException) {            fileNotFoundException.printStackTrace();        }        catch (IOException iOException) {            iOException.printStackTrace();        }    }    public static SqlSessionFactory getSqlSessionFactory() {        return sqlSessionFactory;    }}

Main.java

package com.hmkcode;import java.util.List;import com.hmkcode.mybatis.MyBatisConnectionFactory;import com.hmkcode.dao.PersonDAO;import com.hmkcode.vo.Person;public class Main {    public static void main(String args[]){        // Laod spring-config.xml file        //ApplicationContext ctx = new ClassPathXmlApplicationContext("com/hmkcode/config/spring-config.xml");        //get jdbcTemplatePersonDAO        PersonDAO personDAO = new PersonDAO(MyBatisConnectionFactory.getSqlSessionFactory());        //create person bean to insert        Person person = new Person();        person.setName("Person 1");        //( 1 ) insert person         personDAO.insert(person);        //**set name of person        person.setName("Person 2");         //** insert another person        int id = personDAO.insert(person);        //( 2 ) select persons by id        personDAO.selectById(id);        //( 3 ) select all        List<Person> persons = personDAO.selectAll();        //**set name of all persons        for(int i = 0; i < persons.size(); i++){            persons.get(i).setName("Person Name "+i);            //( 4 ) update person            personDAO.update(persons.get(i));        }        //**check update        persons = personDAO.selectAll();    }}

( 4 ) XML files

• config.xml
• Person.xml

config.xml

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE configuration    PUBLIC "-//mybatis.org//DTD Config 3.0//EN"    "http://mybatis.org/dtd/mybatis-3-config.dtd"><configuration>    <typeAliases>        <typeAlias alias="Person" type="com.hmkcode.vo.Person"/>            </typeAliases>    <environments default="development">        <environment id="development">          <transactionManager type="JDBC"/>            <!--  connecting to Local MySql -->            <dataSource type="POOLED">                <property name="driver" value="com.mysql.jdbc.Driver"/>                <property name="url" value="jdbc:mysql://localhost:3306/hmkcode"/>                <property name="username" value="root"/>                <property name="password" value=""/>            </dataSource>       </environment>    </environments>    <mappers>       <mapper resource="com/hmkcode/mybatis/mapper/Person.xml"/>    </mappers></configuration>###Person.xml

( 5 ) Test Application