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Part I: Creating iBATIS DAOs and Objects in AppFuse - A HowTo for creating Java Objects (that represent tables) and iBATIS DAO classes to persist those objects in the database.

About this tutorial

This tutorial will show you how to create a new table in the database, and how the create Java code to access this table.

You will create an object and then some more classes to persist (save/retrieve/delete) that object from the database. In Java speak, this object is called a Plain Old Java Object (a.k.a. a POJO). This object basically represents a database table. The other classes will be:

  • A Data Access Object (a.k.a. a DAO), an Interface and an iBATIS Implementation
  • A JUnit class to test the DAO is working

AppFuse uses Hibernate for its default persistence layer. However, you can install iBATIS and use it as an alternative. You can also use them both side-by-side if you so desire. To install iBATIS in AppFuse, view the README.txt in extras/ibatis (or simply cd into this directory and run ant install). The Hibernate version of this tutorial is available here.

Font Conventions (work in progress)

Literal strings intended to be executed at the command prompt look like this: ant test-all.
References to files, directories and packages which exist in your source tree: build.xml.
And suggestions for how to do stuff in the "Real World" are in blue italics.

Let's get started on creating a new Object, DAO and Test in AppFuse's project structure.

Table of Contents

  • [1] Create a new Person POJO
  • [2] Create a new database table and mapping file
  • [3] Create a new DaoTest to run JUnit tests on the DAO
  • [4] Create a new DAO to perform CRUD on the object
  • [5] Create a bean definition for the PersonDao
  • [6] Run the DaoTest

Create a new POJO, table and SQLMap [#1]

The first thing you need to do is create an object to persist. Let's create a simple "Person" object (in the src/dao/**/model directory) that has an id, a firstName and a lastName (as properties).

NOTE: Copying the Java code in these tutorials doesn't work in Firefox. A workaround is to CTRL+Click (Command+Click on OS X) the code block and then copy it.

package org.appfuse.model;

public class Person extends BaseObject {
    private Long id;
    private String firstName;
    private String lastName;

     Generate your getters and setters using your favorite IDE: 
     In Eclipse:
     Right-click -> Source -> Generate Getters and Setters

This class should extend BaseObject, which has 3 abstract methods: (equals(), hashCode() and toString()) that you will need to implement in the Person class. The first two are required by Hibernate. The easiest way to do this is using Commonclipse. More information on using this tool can be found on Lee Grey's site. Another Eclipse Plugin you can use is Commons4E. I haven't used it, so I can't comment on its functionality.

If you're using IntelliJ IDEA, you can generate equals() and hashCode(), but not toString(). There is a ToStringPlugin that works reasonably well.
NOTE: If installing these plugins doesn't work for you, you can find all of these methods in the Person.java object that's used to test AppGen. Just look in extras/appgen/test/dao/org/appfuse/model/Person.java and copy and paste the methods from that class.

Create a new database table and mapping file [#2]

Now that you have this POJO created, you need to create a "person" database table that your POJO will map to. Add the following to metadata/sql/mysql-create-tables.sql:
    person_id int(8) auto_increment,
    first_name varchar(50) NOT NULL,
    last_name varchar(50) NOT NULL,
    PRIMARY KEY (person_id)

Then run "ant setup-db". This will create the person table for you. To create the SQL-to-Java mapping file, create PersonSQL.xml in src/dao/**/ibatis/sql. It should contain the following XML:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE sqlMap PUBLIC "-//iBATIS.com//DTD SQL Map 2.0//EN" 

<sqlMap namespace="PersonSQL">
    <typeAlias alias="person" type="org.appfuse.model.Person"/>

    <parameterMap id="addParam" class="person">
        <parameter property="firstName" jdbcType="VARCHAR" javaType="java.lang.String"/>
        <parameter property="lastName" jdbcType="VARCHAR" javaType="java.lang.String"/>

    <parameterMap id="updateParam" class="person">
        <parameter property="personId" jdbcType="INTEGER" javaType="java.lang.Long"/>
        <parameter property="firstName" jdbcType="VARCHAR" javaType="java.lang.String"/>
        <parameter property="lastName" jdbcType="VARCHAR" javaType="java.lang.String"/>

    <resultMap id="personResult" class="person">
        <result property="personId" column="person_id"/>
        <result property="firstName" column="first_name"/>
        <result property="lastName" column="last_name"/>

    <select id="getPersons" resultMap="personResult">
        select * from person

    <select id="getPerson" resultMap="personResult">
        select * from person where person_id = #value#

    <insert id="addPerson" parameterMap="addParam">
        <selectKey resultClass="java.lang.Long" keyProperty="personId">
            insert into person (first_name,last_name)
            values ?,?,? )

    <update id="updatePerson" parameterMap="updateParam">
        update person set
                   first_name = ?,
                   last_name = ?
        where person_id = ?

    <delete id="deletePerson">
        delete from person where person_id = #value#

NOTE: Since iBATIS doesn't support JDBC 3.0's getGeneratedKeys(), you need to use a <selectKey> element that's specific to your database. In this example, the <selectKey> in <insert id="addPerson"> is MySQL's syntax. Of course, if you don't care about fetching the primary key after an object is inserted, you won't need this.

Now you'll need to notify iBATIS that a new SQLMap exists. Open src/dao/**/ibatis/sql-map-config.xml and add the following:

<sqlMap resource="org/appfuse/dao/ibatis/sql/PersonSQL.xml"/>

Create a new DaoTest to run JUnit tests on your DAO [#3]

NOTE: AppFuse versions 1.6.1+ contain include an AppGen tool that can be used to generate all the classes for the rest of these tutorials. However, it's best that you go through these tutorials before using this tool - then you'll know what code it's generating. ;-)

Now you'll create a DaoTest to test that your DAO works. "Wait a minute," you say, "I haven't created a DAO!" You are correct. However, I've found that Test-Driven Development breeds higher quality software. For years, I thought write your test before your class was hogwash. It just seemed stupid. Then I tried it and I found that it works great. The only reason I do all this test-driven stuff now is because I've found it rapidly speeds up the process of software development.

To start, create a PersonDaoTest.java class in the test/dao/**/dao directory. This class should extend BaseDaoTestCase, a subclass of Spring's AbstractTransactionalDataSourceSpringContextTests which already exists in this package. This parent class is used to load Spring's ApplicationContext (since Spring binds the layers together), and for (optionally) loading a .properties file (ResourceBundle) that has the same name as your *Test.class. In this example, if you put a PersonDaoTest.properties file in the same directory as PersonDaoTest.java, this file's properties will be available via an "rb" variable.

package org.appfuse.dao;

import org.appfuse.model.Person;
import org.springframework.dao.DataAccessException;

public class PersonDaoTest extends BaseDaoTestCase {
    private Person person = null;
    private PersonDao dao = null;

    public void setPersonDao(PersonDao dao) {
        this.dao = dao;

The code you see above is what you need for a basic Spring integration test that initializes and configures an implementation of PersonDao. Spring will use autowiring byType to call the setPersonDao() method and set the "personDao" bean as a dependency of this class.

Now you need test that the CRUD (create, retrieve, update, delete) methods work in your DAO. To do this, create methods that begin with "test" (all lower case). As long as these methods are public, have a void return type and take no arguments, they will be called by the <junit> task in build.xml. Below are some simple tests for testing CRUD. An important thing to remember is that each method (also known as a test), should be autonomous. Add the following methods to your PersonDaoTest.java file:

    public void testGetPerson() throws Exception {
        person = new Person();


        person = dao.getPerson(person.getId());

    public void testSavePerson() throws Exception {
        person = dao.getPerson(new Long(1));

        person.setLastName("Last Name Updated");


        if (log.isDebugEnabled()) {
            log.debug("updated Person: " + person);

        assertEquals(person.getLastName()"Last Name Updated");

    public void testAddAndRemovePerson() throws Exception {
        person = new Person();



        if (log.isDebugEnabled()) {
            log.debug("removing person...");


        try {
            person = dao.getPerson(person.getId());
            fail("Person found in database");
        catch (DataAccessException dae) {
            log.debug("Expected exception: " + dae.getMessage());

In the testGetPerson method, you're creating a person and then calling a get. I usually enter a record in the database that I can always rely on. Since DBUnit is used to populate the database with test data before the tests are run, you can simply add the new table/record to the metadata/sql/sample-data.xml file:

<table name='person'>
This way, you can eliminate the "create new" functionality in the testGetPerson method. If you'd rather add this record directly into the database (via SQL or a GUI), you can rebuild your sample-data.xml file using ant db-export and then cp db-export.xml metadata/sql/sample-data.xml.

In the above example, you can see that person.set*(value) is being called to populate the Person object before saving it. This is easy in this example, but it could get quite cumbersome if you're persisting an object with 10 required fields (not-null="true"). This is why I created the ResourceBundle in the BaseDaoTestCase. Simply create a PersonDaoTest.properties file in the same directory as PersonDaoTest.java and define your property values inside it:

I tend to just hard-code test values into Java code - but the .properties file is an option that works great for large objects.
Then, rather than calling person.set* to populate your objects, you can use the BaseDaoTestCase.populate(java.lang.Object) method:

person = new Person();
person = (Personpopulate(person);

At this point, the PersonDaoTest class won't compile yet because there is no PersonDao.class in your classpath, you need to create it. PersonDao.java is an interface, and PersonDaoiBatis.java is the iBATIS implementation of that interface.

Create a new DAO to perform CRUD on the object [#4]

First off, create a PersonDao.java interface in the src/dao/**/dao directory and specify the basic CRUD methods for any implementation classes.

package org.appfuse.dao;

import org.appfuse.model.Person;

public interface PersonDao extends Dao {
    public Person getPerson(Long personId);
    public void savePerson(Person person);
    public void removePerson(Long personId);

Notice in the class above there are no exceptions on the method signatures. This is due to the power of Spring and how it wraps Exceptions with RuntimeExceptions. At this point, you should be able to compile all the source in src/dao and test/dao using ant compile-dao. However, if you try to run ant test-dao -Dtestcase=PersonDao, you will get an error: No bean named 'personDao' is defined. This is an error message from Spring - indicating that you need to specify a bean named personDao in applicationContext-ibatis.xml. Before you do that, you need to create the PersonDao implementation class.

The ant task for running dao tests is called test-dao. If you pass in a testcase parameter (using -Dtestcase=name), it will look for **/*${testcase}* - allowing us to pass in Person, PersonDao, or PersonDaoTest - all of which will execute the PersonDaoTest class.

Let's start by creating a PersonDaoiBatis class that implements the methods in PersonDao and uses iBATIS to get/save/delete the Person object. To do this, create a new class in src/dao/**/dao/ibatis and name it PersonDaoiBatis.java. It should extend BaseDaoiBatis and implement PersonDao.

package org.appfuse.dao.ibatis;

import java.util.List;

import org.appfuse.model.Person;
import org.appfuse.dao.PersonDao;

import org.springframework.orm.ObjectRetrievalFailureException;

public class PersonDaoiBatis extends BaseDaoiBATIS implements PersonDao {

    public Person getPerson(Long personId) {
        Person person = (PersongetSqlMapClientTemplate().queryForObject("getPerson", personId);

        if (person == null) {
            throw new ObjectRetrievalFailureException(Person.class, personId);

        return person;
    public void savePerson(final Person person) {
        Long personId = person.getPersonId();
        // check for new record
        if (personId == null) {
            personId = (LonggetSqlMapClientTemplate().insert("addPerson", person);
        else {
            getSqlMapClientTemplate().update("updatePerson", person);
        ifpersonId == null ) {
            throw new ObjectRetrievalFailureException(Person.class, personId);

    public void removePerson(Long personId) {
        getSqlMapClientTemplate().update("deletePerson", personId);

Now, if you try to run ant test-dao -Dtestcase=PersonDao, you will get the same error. Yo need to configure Spring so it knows that PersonDaoiBatis is the implementation of PersonDao.

Create a bean definition for the PersonDao [#5]

In order to bind PersonDaoiBatis to the PersonDao interface, you need to register a "personDao" bean definition in src/dao/**/dao/ibatis/applicationContext-ibatis.xml. Open this file and add the following at the bottom:

<!-- PersonDao: iBATIS implementation --> 
<bean id="personDao" class="org.appfuse.dao.ibatis.PersonDaoiBatis">
    <property name="dataSource" ref="dataSource"/>
    <property name="sqlMapClient" ref="sqlMapClient"/>

Run the DaoTest [#6]

Save all your edited files and try running ant test-dao -Dtestcase=PersonDao one more time.

Total time: 9 seconds

Next Up: Part II: Creating new Managers - A HowTo for creating Business Facades, which are similar to Session Facades, but don't use EJBs. These facades are used to provide communication from the front-end to the DAO layer.

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This page last changed on 06-Nov-2006 13:53:00 MST by MattRaible.