tips & techniques for using eclipse dali … & techniques for using eclipse dali ... • for...

TIPS & TECHNIQUES FOR USING ECLIPSE DALI TOOLS

TO DEPLOY JPA/JEE APPS ANYWHERE!

March 27, 2012

Ali Manji – Software Analyst, IBM

email: [email protected]

twitter: @torontoIBMer

mailto:[email protected]

http://twitter.com/torontoIBMer

What should we talk about?

Using Eclipse with the Dali Persistence Tools, lets look at techniques to:

1. develop enterprise-grade applications that are either:

a. built from the bottom-up with a pre-existing database

b. built from the top-down starting with business domain entities requiring persistence

storage (e.g. Derby, MySQL, and DB2, Google Big Data)

2. incorporate a JPA approach into your existing JEE architecture

3. minimize data-impedance mismatch issues

2

Take heed!

3

“All generalizations are false, including this one.” – Mark Twain

Development Environment (1 of 2)

IDE Version

Eclipse 3.6 – Helios

3.7 SR 2 – Indigo

IBM Rational Application Developer 8.0.4 (based upon Eclipse 3.6.x)

• For Eclipse environment use the “Eclipse IDE for Java EE Developers”

bundle.

• This bundle contains the Web Tools Project which inclused the Dali JPA project

and the EJB tools project among others

Note: Used JDK or JRE 1.7 for projects and server environments (unless provided by the IDE or

Application Server)

4

Development Environment (2 of 2)

Plugins / Features Version

Google Plugin For Eclipse 2.5.2 (for Eclipse 3.7)

Oracle Glassfish Server Tools 2.0.0 – Download from “New Server” wizard

JBossAS Tools 2.3.0 – Download from “New Server” wizard

5

Caution: Building on a stack…always a work in progress

6

“The road to success is always under construction.” – Lily Tomlin

Source: http://www.flickr.com/photos/tmray02/4639274135, Tom Ray

http://www.flickr.com/photos/tmray02/4639274135

http://www.flickr.com/photos/tmray02/4639274135

JEE Deployment Topologies

Derby MySQL DB2

GlassFish Server Open Source Edition Y Y Y

WebSphere Application Server (1) Y Y Y

Google App Engine N/A N/A N/A

JBoss Y Y Y

* (1) Used IBM Rational development environment – Rational Application Developer

to exploit OOTB server tooling add-ons and other productivity conveniences for

WebSphere Application Server v8 test/deployment

7

Application Servers

Application Server Version

GlassFish Server Open Source Edition (See Note 1) 3.1.2 (JEE6)

WebSphere Application Server 8.0.0.2

JBoss (See Note 2) 7.1

Google App Engine (uses Jetty) 1.6.3

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Note 1:

• Made use of EclipseLink 2.3.2 (for Indigo) JPA Platform / User Library implementation

donated by Oracle (TopLink)

Note 2:

• Makes use of Hibernate JPA implementation

Data stores

Database / Data store Version

Derby 10.8.2.2

MySQL Community Server

Connector J (JBDC Driver)

5.5.21

5.1.18

DB2 Enterprise Server Edition 9.7 (on Red Hat Linux)

Google Big Table 1.6.3

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a. built from the bottom-up with pre-existing database





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“Bottom-up” JPA Tips / Techniques (1 of 4)

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1. Limit navigability of relationships (tighter encapsulation / data hiding).

PrimaryMember has a bi-directional relationship with Address

PrimaryMember has an address (good!)

Address has a collection of Primarymembers (not so good!)


12

1. Limit navigability of relationships (tighter encapsulation / data hiding).


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2. “Clean-up” generated code to reflect true 1-1 aggregate relationships.

• Most/many DBs do NOT support 1-1 relationships for performance reasons, BUT

• Simple aggregate relationships are COMMON in Java-based domain

models/designs

• This is an example of where the data-impedance mismatch problem

manifests itself between the 2 different “world-views” (i.e. relational tables

vs. objects as real-world abstractions)

After:

Before:

http://en.wikipedia.org/wiki/Object-relational_impedance_mismatch




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3. Adjust generated code to reflect rich Java types that can be mapped from

less rich primitives or other types as introspected from the DBs

• You have options. e.g. Date, Timestamp, Calendar, etc.





b. built from the top-down starting with business domain entities requiring

persistence storage (e.g. Derby, MySQL, and DB2, Google Big Data)



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Uniqueness

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“Always remember you're unique, just like everyone else.” – Alison Boulter

Source: http://www.flickr.com/photos/amboo213/5562707049, Amboo

http://www.flickr.com/photos/amboo213/5562707049

http://www.flickr.com/photos/amboo213/5562707049

“Top-down” JPA Tips / Techniques

1. Use the data store’s native features to automatically generate values for

your class’s id attributes.

• Value lies in abstracting away the focus of your data store’s requirement for a

unique key value. Application’s business logic is paramount

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SQL for Unique ID generation

For MySQL

CREATE TABLE BANK.Customer (clientID INTEGER NOT NULL AUTO_INCREMENT, firstName

VARCHAR(255), lastName VARCHAR(255), yearOfBirth INTEGER, PRIMARY KEY (clientID))

ENGINE = innodb;

For DB2 / Derby:

CREATE TABLE NULLID.CUSTOMER (

CLIENTID INTEGER NOT NULL GENERATED ALWAYS AS IDENTITY (START WITH +0,

INCREMENT BY +1),

FIRSTNAME VARCHAR(254), LASTNAME VARCHAR(254), YEAROFBIRTH INTEGER, PRIMARY

KEY (clientid));

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Incorporating JPA into existing JEE Architecture

1. JPA is annotation and Resource Injection (RI) friendly, use them wherever possible

• Eliminate messy JNDI code for resource declarations, lookup, and initialization

NOTE: Only works with complete & compliant JEE Application Servers

• E.g. Google App Engine not a complete JEE container.. (Reference over

here)

2. Use JPA with your AppServer’s Transaction Management support wherever possible

(container management / connection pooling).

3. Continue good practice common to wrapper JPA bean in front of a session bean (to

secure container management services)

• In JEE 6, possible to use as JPA beans as a “managed bean” for direct access in

JSF pages (and facelets).

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http://groups.google.com/group/google-appengine-java/browse_thread/thread/2858ecddc4f23835?pli=1









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Questions

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Thank You

Ali Manji – Software Developer, IBM

email: [email protected]

twitter: @torontoIBMer

Tips & Techniques for using Eclipse Dali Tools to deploy JPA/JEE

Apps anywhere!

mailto:[email protected]

http://twitter.com/torontoIBMer

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2 Select Session Evaluate

3 Vote

Back-up

24

Adding Server Adapters to your Eclipse Development

Environment (1 of 3)

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Question: Why use a Server adapter?

Answer: Fabulous productivity enhancer, for test, debug, deploy roundtrip cycle

Eliminate or minimize need to:

1. To leave your Eclipse environment to test/debug your application

2. To understand the AppServer’s deployment process, file structure, configuration

– development abstraction

3. Cycle of zipping up jars, wars, ears and copying over and restarting application

or entire server

With most server adapters the following steps in the below cycle are automatic:

1. Detection of changes to application

2. Re-published

3. Applications are restarted

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EclipseLink with Glassfish – 1 of 3

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29


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Key steps/considerations for Google App Engine (GAE) – 1 of 2

1. GAE runtime needs JDK using JRE not sufficient.

2. Google has its own Web Project that you have to use and it is different from Java EE

> Dynamic Web Project

3. Using Oracle’s JDK requires use of the JVM argument: -XX:-UseSplitVerifier

4. GAE does not have support for many JPA annotations, notably these:

@PersistenceContext EntityManager em;

@Resource private UserTransaction utx;

Have to use programmatic alternative instead:

EntityManager em = EMF.get().createEntityManager();

…..

EntityTransaction utx = em.getTransaction();

31

Key steps/considerations for Google App Engine (GAE) – 2 of 2

1. JEE 6 Annotations also not available yet for Web Containers: Can’t use this annotation yet: @WebServlet("/CreateCustomerServlet")

2. GAE/DataNucleus has some specific limitations on types that you can use to

represent the ID/Primary key field. You can’t use private int clientID; More details

here.

3. In addition to these annotations required by JPA

@Id

@GeneratedValue(strategy = IDENTITY)

MUST ALSO USE

@PrimaryKey

@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)

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http://code.google.com/appengine/docs/java/datastore/jdo/creatinggettinganddeletingdata.html

Google App Engine Considerations

33

Google App Engine – persistence.xml

<?xml version="1.0" encoding="UTF-8" ?>

<persistence xmlns="http://java.sun.com/xml/ns/persistence"

xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi:schemaLocation="http://java.sun.com/xml/ns/persistence

http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" version="1.0">

<persistence-unit name="transactions-optional">

<provider>org.datanucleus.api.jpa.PersistenceProviderImpl</provider>

<class>org.acme.membership.domain.Membership</class>

<properties>

<property name="datanucleus.NontransactionalRead" value="true"/>

<property name="datanucleus.NontransactionalWrite" value="true"/>

<property name="datanucleus.ConnectionURL" value="appengine"/>

</properties>

</persistence-unit>

</persistence>

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JDO with Google App Engine

http://www.ibm.com/developerworks/rational/library/building

-java-data-objects-application-using-rational-software-

architect-and-google-application-engine/index.html

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http://www.ibm.com/developerworks/rational/library/building-java-data-objects-application-using-rational-software-architect-and-google-application-engine/index.html

























Key steps/considerations for Glassfish

1. GlassFish runtime needs JDK using JRE not sufficient

2. Download EclipseLink to use along with Glassfish

3. Create (proprietary) file glassfish-resources.xml in the EAR’s meta-inf directory

(http://javahowto.blogspot.com/2011/02/glassfish-embedded-jpa-ejb-datasource.html)

4. Copy JBDC drivers from vendor to: X:\glassfish3\glassfish\lib • (except Derby)

36

Glassfish with Derby: persistence.xml

<?xml version="1.0" encoding="UTF-8"?>

<persistence version="2.0"

…..

<jta-data-source>java:app/jdbc/BANK</jta-data-source>

<class>org.acme.bank.domain.Customer</class>

<properties>

<property name="eclipselink.target-database" value="Derby" />

</properties>

</persistence-unit>

</persistence>

37

Glassfish with Derby: glassfish-resources.xml

<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE resources PUBLIC "-//GlassFish.org//DTD GlassFish Application Server 3.1 Resource Definitions//EN" "http://glassfish.org/dtds/glassfish-resources_1_5.dtd"> <resources> <jdbc-connection-pool name="derbyGF_CustomerPool" res-type="javax.sql.DataSource" datasource classname="org.apache.derby.jdbc.ClientDataSource40" pool-resize-quantity="1" max-pool-size="5" steady-pool-size="0" statement-timeout-in-seconds="60"> <property name="serverName" value="localhost" /> <property name="portNumber" value="1527" /> <property name="dataBaseName" value="D:\DERBY_DBS\BANK" /> <property name="connectionAttributes" value=";create=true" /> <property name="driverType" value="4" /> <property name="user" value=“USER" /> <property name="password" value=“PASSWORD" /> </jdbc-connection-pool> <jdbc-resource enabled="true" jndi-name="jdbc/BANK" object-type="user" pool-name="derbyGF_CustomerPool" /> </resources>

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GlassFish with MySQL: persistence.xml


<persistence version="2.0“ xmlns="http://java.sun.com/xml/ns/persistence"



http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">

<persistence-unit name="BankAppWeb">



<properties>

<property name="eclipselink.target-database" value="MySQL4" />

</properties>

</persistence-unit>

</persistence>

39

Glassfish with MySQL: glassfish-resources.xml


<!DOCTYPE resources PUBLIC "-//GlassFish.org//DTD GlassFish Application Server 3.1 Resource Definitions//EN"

"http://glassfish.org/dtds/glassfish-resources_1_5.dtd">

<resources>

<jdbc-connection-pool name=“mySQLGF_CustomerPool"

res-type="javax.sql.DataSource" datasource-classname="com.mysql.jdbc.jdbc2.optional.MysqlConnectionPoolDataSource"

pool-resize-quantity="1" max-pool-size="5" steady-pool-size="0"

statement-timeout-in-seconds="60">

<property name="serverName" value="localhost" />

<property name="portNumber" value="3306" />

<property name="dataBaseName" value="BANK" />

<property name="connectionAttributes" value=";create=true" />

<property name="driverType" value="4" />

<property name="user" value="root" />

<property name="password" value=“PASSWORD" />

</jdbc-connection-pool>

<jdbc-resource enabled="true" jndi-name="jdbc/BANK"

object-type="user" pool-name=“mySQLGF_CustomerPool" />

</resources>

40

Key steps/considerations for Glassfish with DB2

With GlassFish additionally requires specifying DB2’s schema value – even if you use the default

schema value for the database (e.g. NULLID).

Solution from Neil Hague:

The standard JPA solution to setting a default schema for your persistence unit is to configure the schema setting in the persistence-unit-

defaults. This is defined in 1 and only 1 XML Mapping file (orm.xml) as follows:

<entity-mappings ...>

<persistence-unit-metadata>

<persistence-unit-defaults>

<schema>default_schema_name</schema>

</persistence-unit-defaults>

...

</entity-mappings>

Source over here

Alternative solution:

• Explicitly include schema attribute in table annotation for each class:

@Table(schema = "NULLID")

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http://wiki.eclipse.org/User:Neil.hauge.oracle.com

http://www.eclipse.org/forums/index.php?t=rview&goto=720056

Glassfish with DB2: persistence.xml


<persistence version="2.0"

xmlns="http://java.sun.com/xml/ns/persistence"



http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd">

<persistence-unit name="BankAppWeb">



<properties>

<property name="eclipselink.target-database" value="DB2" />

</properties>

</persistence-unit>

</persistence>

42

Glassfish with DB2: glassfish-resources.xml


<!DOCTYPE resources PUBLIC "-//GlassFish.org//DTD GlassFish Application Server 3.1 Resource Definitions//EN"

"http://glassfish.org/dtds/glassfish-resources_1_5.dtd">

<resources>

<jdbc-connection-pool name="derbyGF_CustomerPool"

res-type="javax.sql.DataSource" datasource-classname="com.ibm.db2.jcc.DB2SimpleDataSource"

pool-resize-quantity="1" max-pool-size="5" steady-pool-size="0"

statement-timeout-in-seconds="60" >

<property name="serverName" value="hasanali.torolab.ibm.com" />

<property name="portNumber" value="50000" />

<property name="databaseName" value="BANK" />

<property name="driverType" value="4" />

<property name="user" value="db2inst1" />

<property name="password" value=“PASSWORD" />

</jdbc-connection-pool>

<jdbc-resource enabled="true" jndi-name="jdbc/BANK"

object-type="user" pool-name="derbyGF_CustomerPool" />

</resources>

43

WebSphere Application Server

With Derby

http://www.ibm.com/developerworks/rational/library/jpa-rational-application-

developer-was-8

With DB2

http://www.ibm.com/developerworks/rational/library/10/create-bottom-up-jpa-

entities-with-rational-application-developer-db2-and-websphere-application-

server/index.html

With MySQL

• No Support for MySQL in WebSphere Application Server

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http://www.ibm.com/developerworks/rational/library/jpa-rational-application-developer-was-8













http://www.ibm.com/developerworks/rational/library/10/create-bottom-up-jpa-entities-with-rational-application-developer-db2-and-websphere-application-server/index.html




























Key steps/considerations for JBoss

1. Runtime needs JDK using JRE not sufficient

2. Uses Hibernate JPA implementation

3. Copy Database libraries (JARs) to: JBOSS_HOME\modules\XXXX – where you

create directory XXXX

4. Create (proprietary) file module.xml which goes in directory created created in #2

5. Update (proprietary) standalone.xml to define data source information

45

JBoss with MySQL: module.xml / standalone.xml

module.xml

<?xml version="1.0" encoding="UTF-8"?> <module xmlns="urn:jboss:module:1.0" name="com.mysql"> <resources> <resource-root path="mysql-connector-java-5.1.18-bin.jar"/> </resources> <dependencies> <module name="javax.api"/> </dependencies> </module>

Excerpt of standalone.xml

<datasource jta="true" jndi-name="java:/MyBankDB2DS" pool-name="MyBankDB2DS" enabled="true" use-java-context="true" use-ccm="true"> <connection-url>jdbc:db2://hasanali.torolab.ibm.com:50000/MyBank:retrieveMessagesFromServerOnGetMessage=true;</connection-url> <driver>db2jcc</driver> <security> <user-name>db2inst1</user-name> <password>PASSWORD</password> </security> <timeout> <idle-timeout-minutes>0</idle-timeout-minutes> <query-timeout>600</query-timeout> </timeout> </datasource>

46

JBoss persistence.xml

Excerpts of persistence.xml

…



<jta-data-source>java:/MyBankMySQLDS</jta-data-source>

…



<property name="showSql" value="true"/>

<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" />

…

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Porting Databases between vendors/providers – 1 of 2

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Porting Databases between vendors/providers – 2 of 2

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