iBATIS

Omaha Java Users Group

March 18, 2008

Corey A. Spitzer

The Context

• J2EE (with Spring)

• OOP

• SQL Relational Database

What is iBATIS?

DatabaseLogic / DAO

CodeiBATIS

Object Oriented

Relational

Object

Query

A More Detailed Look

SqlMapClient

SQL Maps

insert()

update()

delete()

query()

loads

javax.sql.DataSource

calls

Queries

Result Maps

Database

MagicMagic

Codecalls

The SQL Map Anatomy

<sqlMap namespace="myNamespace">

<resultMap id="myClass" class="full.package.MyClass">

<result property="foo" column="col1"/>

<result property="bar" column="col2"/>

...

</resultMap>

...

<!-- ===================================================== -->

<sql id="myQuery" resultMap="myClass">

SELECT col1, col2 FROM table1

</sql>

...

</sqlMap>

SqlMapClient

SQL Maps

loads

DataSource

calls

Database

MagicMagic

Codecalls

The Code Anatomyimport java.sql.SQLException;

import com.ibatis.sqlmap.client.SqlMapClient;

...

public class MyDAO

{

private SqlMapClient myDB;

public void frobnicate(MyObject someObject) throws SQLException

{

List<MyClass> list = myDB.queryForList("myQuery");

Foo myFoo = (Foo)myDB.queryForObject("getFooByID", 1337);

myDB.update("myQuery3");

myDB.insert("myQuery4", someObject);

...

}

...

}

SqlMapClient

SQL Maps

loads

DataSource

calls

Database

MagicMagic

Codecalls

Any Questions so far?

SqlMapClient

SQL Maps

insert()

update()

delete()

query()

loads

javax.sql.DataSource

calls

Queries

Result Maps

Database

MagicMagic

Codecalls

Implicit Mapping

<sqlMap namespace="myNamespace">

<resultMap id="myClass" class="full.package.Class">

<result property="foo" column="col1"/>

<result property="bar" column="col2"/>

...

</resultMap>

...

<!-- ===================================================== -->

<sql id="myQuery" resultClass="full.package.Class">

SELECT col1 as foo, col2 as bar FROM table1

</sql>

...

</sqlMap>

Inheritance

Fruit

id - int

dateBought - long

Apple

wormCount - float

Orange

bioengineered - boolean

Object Oriented Code Relational Database

fruits

id - mediumint(7), PK

date_bought - int(11)

type - enum('a', 'o')

apples

fruit_id - mediumint(7), FK

worm_count - decimal(4,1)

oranges

fruit_id - mediumint(7), FK

bioengineered - bool

Complex Members

Cake

id - int

flavor - String

toppings - List<CakeTopping>

CakeTopping

id - int

name - String

containsHFCS - boolean

Object Oriented Code Relational Database

cakes

id - mediumint(7), PK

flavor - enum('chocolate', ...)

cakes_to_toppings

cake_id - mediumint(7), FK

topping_id - mediumint(7), FK

cake_toppings

id - mediumint(7), PK

name - varchar(20)

contains_hfcs - bool

Parameters & Dynamic Queries

Custom Type Handlers

public class YesNoBoolTypeHandler implements TypeHandlerCallback {

public Object getResult(ResultGetter getter) throws SQLException {

if ("Y".equalsIgnoreCase(getter.getString())) {

return new Boolean (true);

} else if ("N".equalsIgnoreCase(getter.getString())) {

return new Boolean (false);

} else {

throw new SQLException();

}

}

public void setParameter(ParameterSetter setter, Object parameter) throws SQLException {

if (((Boolean)parameter).booleanValue()) setter.setString("Y");

else setter.setString("N");

}

public Object valueOf(String s) {

return new Boolean ("Y".equalsIgnoreCase(s));

}

}

Custom Type Handlers

<resultMap id="myClass" class="my.package.MyClass">

...

<result property="foo" column="bar" typeHandler="some.package.YesNoBoolTypeHandler"/>

...

</resultMap>

<insert id="myQuery" resultMap="myClass" parameterClass="my.package.MyClass">

INSERT INTO table1 SET bar = #foo,handler=some.package.YesNoBoolTypeHandler#

</insert>

Paging / Selecting a Range

selectKey

<insert id="addForumThread" parameterClass="java.util.HashMap">

INSERT INTO forum_threads SET

forum_id = #forumID#,

title = #title#,

created_time = #createdTime#,

last_updated_time = #createdTime#,

<selectKey resultClass="int">

SELECT MAX(id) FROM forum_threads

</selectKey>

</insert>

Caching Features

<cacheModel id="fooCache" type="{LRU|MEMORY|FIFO|OSCACHE}" readOnly="{true|false}" serialize="{true|false}">

<flushInterval hours="24"/>

<flushOnExecute statement="insertFoo"/>

<flushOnExecute statement="updateFoo"/>

<flushOnExecute statement="deleteFoo"/>

<property name="size" value="1000"/>

</cacheModel>

<select id="getFoo" cacheModel="fooCache">

SELECT * FROM bar WHERE id = #value#

</select>

<insert id="insertFoo">

INSERT INTO bar SET ...

</insert>

...

Transactions

public updateItemDescription(String itemId, String newDescription) throws SQLException{

try {

sqlMap.startTransaction();

Item item = (Item) sqlMap.queryForObject("getItem", itemId);

item.setDescription (newDescription);

sqlMap.update("updateItem", item);

sqlMap.commitTransaction();} finally {

sqlMap.endTransaction();}

}

What About Hibernate?

• Separation of code and SQL

• Simpler configuration and setup*

• Total control over SQL queries

• Shallow learning curve

• Handles application complexities

better**

iBATIS Hibernate• SQL alongside code

• Cross-DB query language (HQL)

• ???

• Works very well when data model

closely resembles object model**

**No Fluff Just Stuff's Mark Richards' two cents:

http://www.nofluffjuststuff.com/media.jsp?mediaId=27

*Source: http://www.devx.com/Java/Article/31481/0/page/1

Who is Using iBatis?

• CNet.com

• MySpace.com

• OfficeMax.com

• JPMorganChase.com

• 1up.com

• PowerSentry.com

(and more)

Source: http://www.ociweb.com/mark/programming/iBATIS.html#WhoUses

Now What?

http://ibatis.apache.org