TOTD
#166 explained how to use MongoDB in your Java EE 6
applications. The code in that tip used the APIs exposed by the MongoDB
Java driver and so requires you to learn a new API. However if
you are building Java EE 6 applications then you are already
familiar with Java Persistence API (JPA). Eclipse
Link 2.4, scheduled to release as part of Eclipse
Juno, provides
support for NoSQL
databases by mapping a JPA entity to a document. Their wiki
provides complete explanation of how the mapping is done.
This Tip Of The Day
(TOTD) will show how you can leverage that
support in your Java EE 6
applications deployed on GlassFish
3.1.2.
Before we dig into the code, here are the key concepts ...
A POJO is mapped to a NoSQL data source using @NoSQL or
<no-sql> element in "persistence.xml".
A subset of JPQL and Criteria query are supported, based upon
the underlying data store
Connection properties are defined in "persistence.xml"
Now, lets lets take a look at the code ...
Download the latest EclipseLink
2.4 Nightly Bundle. There is a Installer, Source, and
Bundle - make sure to download the Bundle link (20120410)
and unzip.
Download GlassFish
3.1.2 zip and unzip.
Install the Eclipse Link 2.4 JARs in GlassFish
Remove the following JARs from "glassfish/modules":
org.eclipse.persistence.antlr.jar
org.eclipse.persistence.asm.jar
org.eclipse.persistence.core.jar
org.eclipse.persistence.jpa.jar
org.eclipse.persistence.jpa.modelgen.jar
org.eclipse.persistence.moxy.jar
org.eclipse.persistence.oracle.jar
Add the following JARs from Eclipse Link 2.4 nightly build
to "glassfish/modules":
org.eclipse.persistence.antlr_3.2.0.v201107111232.jar
org.eclipse.persistence.asm_3.3.1.v201107111215.jar
org.eclipse.persistence.core.jpql_2.4.0.v20120407-r11132.jar
org.eclipse.persistence.core_2.4.0.v20120407-r11132.jar
org.eclipse.persistence.jpa.jpql_2.0.0.v20120407-r11132.jar
org.eclipse.persistence.jpa.modelgen_2.4.0.v20120407-r11132.jar
org.eclipse.persistence.jpa_2.4.0.v20120407-r11132.jar
org.eclipse.persistence.moxy_2.4.0.v20120407-r11132.jar
org.eclipse.persistence.nosql_2.4.0.v20120407-r11132.jar
org.eclipse.persistence.oracle_2.4.0.v20120407-r11132.jar
Start MongoDB
Download latest MongoDB
from here (2.0.4 as of this writing).
Create the default data directory for MongoDB as:
sudo mkdir -p /data/db/sudo chown `id -u` /data/db
Refer to Quickstart
for more details.
Start MongoDB as:
arungup-mac:mongodb-osx-x86_64-2.0.4 <arungup> ->./bin/mongod./bin/mongod --help for help and startup optionsMon Apr 9 12:56:02 [initandlisten] MongoDB starting : pid=3124 port=27017 dbpath=/data/db/ 64-bit host=arungup-mac.localMon Apr 9 12:56:02 [initandlisten] db version v2.0.4, pdfile version 4.5Mon Apr 9 12:56:02 [initandlisten] git version: 329f3c47fe8136c03392c8f0e548506cb21f8ebfMon Apr 9 12:56:02 [initandlisten] build info: Darwin erh2.10gen.cc 9.8.0 Darwin Kernel Version 9.8.0: Wed Jul 15 16:55:01 PDT 2009; root:xnu-1228.15.4~1/RELEASE_I386 i386 BOOST_LIB_VERSION=1_40Mon Apr 9 12:56:02 [initandlisten] options: {}Mon Apr 9 12:56:02 [initandlisten] journal dir=/data/db/journalMon Apr 9 12:56:02 [initandlisten] recover : no journal files present, no recovery neededMon Apr 9 12:56:02 [websvr] admin web console waiting for connections on port 28017Mon Apr 9 12:56:02 [initandlisten] waiting for connections on port 27017
Check out the JPA/NoSQL sample from SVN
repository. The complete source code built in this TOTD
can be downloaded
here.
Create Java EE 6 web app
Create a Java EE 6 Maven web app as:
mvn archetype:generate
-DarchetypeGroupId=org.codehaus.mojo.archetypes
-DarchetypeArtifactId=webapp-javaee6
-DgroupId=model -DartifactId=javaee-nosql
-DarchetypeVersion=1.5 -DinteractiveMode=false
Copy the model files from the checked out workspace to the
generated project as:
cd javaee-nosqlcp -r ~/code/workspaces/org.eclipse.persistence.example.jpa.nosql.mongo/src/model src/main/java
Copy "persistence.xml"
mkdir src/main/resources
cp -r ~/code/workspaces/org.eclipse.persistence.example.jpa.nosql.mongo/src/META-INF ./src/main/resources
Add the following dependencies:
<dependency> <groupId>org.eclipse.persistence</groupId> <artifactId>org.eclipse.persistence.jpa</artifactId> <version>2.4.0-SNAPSHOT</version> <scope>provided</scope></dependency><dependency> <groupId>org.eclipse.persistence</groupId> <artifactId>org.eclipse.persistence.nosql</artifactId> <version>2.4.0-SNAPSHOT</version></dependency><dependency> <groupId>org.mongodb</groupId> <artifactId>mongo-java-driver</artifactId> <version>2.7.3</version></dependency>
The first one is for the EclipseLink latest APIs, the second
one is for EclipseLink/NoSQL
support, and the last one is the
MongoDB Java driver.
And the following repository:
<repositories>
<repository> <id>EclipseLink Repo</id> <url>http://www.eclipse.org/downloads/download.php?r=1&nf=1&file=/rt/eclipselink/maven.repo</url> <snapshots> <enabled>true</enabled> </snapshots> </repository> </repositories>
Copy the "Test.java" to the generated project:
mkdir src/main/java/examplecp -r ~/code/workspaces/org.eclipse.persistence.example.jpa.nosql.mongo/src/example/Test.java ./src/main/java/example/
This file contains the source code to CRUD the JPA entity to
MongoDB. This sample is explained in detail on EclipseLink
wiki.
Create a new Servlet in "example" directory as:
package example;import java.io.IOException;import java.io.PrintWriter;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * @author Arun Gupta */@WebServlet(name = "TestServlet", urlPatterns = {"/TestServlet"})public class TestServlet extends HttpServlet { protected void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=UTF-8"); PrintWriter out = response.getWriter(); try { out.println("<html>"); out.println("<head>"); out.println("<title>Servlet TestServlet</title>"); out.println("</head>"); out.println("<body>"); out.println("<h1>Servlet TestServlet at " + request.getContextPath() + "</h1>"); try { Test.main(null); } catch (Exception ex) { ex.printStackTrace(); } out.println("</body>"); out.println("</html>"); } finally { out.close(); } } @Override protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { processRequest(request, response); } @Override protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { processRequest(request, response); }}
Build the project and deploy it as:
mvn clean packageglassfish3/bin/asadmin deploy --force=true target/javaee-nosql-1.0-SNAPSHOT.war
Accessing http://localhost:8080/javaee-nosql/TestServlet
shows the following messages in the server.log:
connecting(EISLogin( platform=> MongoPlatform user name=> "" MongoConnectionSpec()))
. . .Connected: User: Database: 2.7 Version: 2.7 . . .Executing MappedInteraction() spec => null properties => {mongo.collection=CUSTOMER, mongo.operation=INSERT} input => [DatabaseRecord( CUSTOMER._id => 4F848E2BDA0670307E2A8FA4 CUSTOMER.NAME => AMCE)]. . .Data access result: [{TOTALCOST=757.0, ORDERLINES=[{DESCRIPTION=table, LINENUMBER=1, COST=300.0}, {DESCRIPTION=balls, LINENUMBER=2, COST=5.0}, {DESCRIPTION=rackets, LINENUMBER=3, COST=15.0}, {DESCRIPTION=net, LINENUMBER=4, COST=2.0}, {DESCRIPTION=shipping, LINENUMBER=5, COST=80.0}, {DESCRIPTION=handling, LINENUMBER=6, COST=55.0},{DESCRIPTION=tax, LINENUMBER=7, COST=300.0}], SHIPPINGADDRESS=[{POSTALCODE=L5J1H7, PROVINCE=ON, COUNTRY=Canada, CITY=Ottawa,STREET=17 Jane St.}], VERSION=2, _id=4F848E2BDA0670307E2A8FA8,DESCRIPTION=Pingpong table, CUSTOMER__id=4F848E2BDA0670307E2A8FA7, BILLINGADDRESS=[{POSTALCODE=L5J1H8, PROVINCE=ON, COUNTRY=Canada, CITY=Ottawa, STREET=7 Bank St.}]}]
You'll not see any output in the browser, just the output in the
console. But the code can be easily modified to do so.
Once again, the complete Maven project can be downloaded
here.
Do you want to try accessing relational and non-relational (aka
NoSQL) databases in the same PU ?
