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<!DOCTYPE html>

<head>

<title>The phonebilling Example Application</title>

</head>

<body>

<tr>

<b>Java Platform, Enterprise Edition (Java EE) 8</b><br />

<b>The Java EE Tutorial</b>

</td>

</tr>

</table>

<hr />

</colgroup>

<tr>

<span style="position:relative;top:-2px;">Previous</span>

</a>

</td>

</a>

</td>

<span style="position:relative;top:-2px;">Contents</span>

</a>

</td>

</tr>

</table>

</div>

<h2 id="_the_phonebilling_example_application">The phonebilling Example Application</h2>

<p>The <code>phonebilling</code> example application, located in the

tut-install`/examples/batch/phonebilling/` directory, demonstrates how

to use the batch framework in Java EE to implement a phone billing

system. This example application processes a log file of phone calls and

creates a bill for each customer.</p>

</div>

<p>The following topics are addressed here:</p>

</div>

<ul>

<li>

<p><a href="#BABDEIFG">Architecture of the phonebilling Example Application</a></p>

</li>

<li>

<p><a href="#BABBGDAA">Running the phonebilling Example Application</a></p>

</li>

</ul>

</div>

</div>

<h3 id="_architecture_of_the_phonebilling_example_application">Architecture of the phonebilling Example Application</h3>

<p>The <code>phonebilling</code> example application consists of the following

elements.</p>

</div>

<ul>

<li>

<p>A job definition file (<code>phonebilling.xml</code>) that uses the Job

Specification Language (JSL) to define a batch job with two chunk steps.

The first step reads call records from a log file and associates them

with a bill. The second step computes the amount due and writes each

bill to a text file.</p>

</li>

<li>

<p>A Java class (<code>CallRecordLogCreator</code>) that creates the log file for

the batch job. This is an auxiliary component that does not demonstrate

any key functionality in this example.</p>

</li>

<li>

<p>Two Java Persistence API (JPA) entities (<code>CallRecord</code> and <code>PhoneBill</code>)

that represent call records and customer bills. The application uses a

JPA entity manager to store instances of these entities in a database.</p>

</li>

<li>

<p>Three batch artifacts (<code>CallRecordReader</code>, <code>CallRecordProcessor</code>, and

<code>CallRecordWriter</code>) that implement the first step of the application.

This step reads call records from the log file, associates them with a

bill, and stores them in a database.</p>

</li>

<li>

<p>Four batch artifacts (<code>BillReader</code>, <code>BillProcessor</code>, <code>BillWriter</code>, and

<code>BillPartitionMapper</code>) that implement the second step of the

application. This step is a partitioned step that gets each bill from

the database, calculates the amount due, and writes it to a text file.</p>

</li>

<li>

<p>Two Facelets pages (<code>index.xhtml</code> and <code>jobstarted.xhtml</code>) that provide

the front end of the batch application. The first page shows the log

file that will be processed by the batch job, and the second page

enables the user to check on the status of the job and shows the

resulting bill for each customer.</p>

</li>

<li>

<p>A managed bean (<code>JsfBean</code>) that is accessed from the Facelets pages.

The bean submits the job to the batch runtime, checks on the status of

the job, and reads the text files for each bill.</p>

</li>

</ul>

</div>

</div>

<h4 id="_the_job_definition_file">The Job Definition File</h4>

<p>The <code>phonebilling.xml</code> job definition file is located in the

<code>WEB-INF/classes/META-INF/batch-jobs/</code> directory. The file specifies

three job-level properties and two steps:</p>

</div>

<job id="phonebilling" xmlns="http://xmlns.jcp.org/xml/ns/javaee"

version="1.0">

</properties>

</job></code></pre>

</div>

<p>The first step is defined as follows:</p>

</div>

</chunk>

</step></code></pre>

</div>

<p>This step is a normal chunk step that specifies the batch artifacts that

implement each phase of the step. The batch artifact names are not fully

qualified class names, so the batch artifacts are CDI beans annotated

with <code>@Named</code>.</p>

</div>

<p>The second step is defined as follows:</p>

</div>

</chunk>

</partition>

</step></code></pre>

</div>

<p>This step is a partitioned chunk step. The partition plan is specified

through the <code>BillPartitionMapper</code> artifact instead of using the <code>plan</code>

element.</p>

</div>

</div>

<h4 id="_the_callrecord_and_phonebill_entities">The CallRecord and PhoneBill Entities</h4>

<p>The <code>CallRecord</code> entity is defined as follows:</p>

</div>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">@Entity

public class CallRecord implements Serializable {

@Id @GeneratedValue

private Long id;

@Temporal(TemporalType.DATE)

private Date datetime;

private String fromNumber;

private String toNumber;

private int minutes;

private int seconds;

private BigDecimal price;

public CallRecord() { }

public CallRecord(String datetime, String from,

String to, int min, int sec) throws ParseException { ... }

public CallRecord(String jsonData) throws ParseException { ... }

/* ... Getters and setters ... */

}</code></pre>

</div>

<p>The <code>id</code> field is generated automatically by the JPA implementation to

store and retrieve <code>CallRecord</code> objects to and from a database.</p>

</div>

<p>The second constructor creates a <code>CallRecord</code> object from an entry of

JSON data in the log file using the JSON Processing API. Log entries

look as follows:</p>

</div>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">{"datetime":"03/01/2013 04:03","from":"555-0101",

"to":"555-0114","length":"03:39"}</code></pre>

</div>

<p>The <code>PhoneBill</code> entity is defined as follows:</p>

</div>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">@Entity

public class PhoneBill implements Serializable {

@Id

private String phoneNumber;

@OneToMany(fetch = FetchType.EAGER, cascade = CascadeType.PERSIST)

@OrderBy("datetime ASC")

private List<CallRecord> calls;

private BigDecimal amountBase;

private BigDecimal taxRate;

private BigDecimal tax;

private BigDecimal amountTotal;

public PhoneBill() { }

public PhoneBill(String number) {

this.phoneNumber = number;

calls = new ArrayList<>();

}

public void addCall(CallRecord call) {

calls.add(call);

}

public void calculate(BigDecimal taxRate) { ... }

/* ... Getters and setters ... *

}</code></pre>

</div>

<p>The <code>OneToMany</code> annotation defines the relationship between a bill and

its call records. The <code>FetchType.EAGER</code> attribute specifies that the

collection should be retrieved eagerly. The <code>CascadeType.PERSIST</code>

attribute indicates that the elements in the call list should be

automatically persisted when the phone bill is persisted. The <code>OrderBy</code>

annotation defines an order for retrieving the elements of the call list

from the database.</p>

</div>

<p>The batch artifacts use instances of these two entities as items to

read, process, and write.</p>

</div>

<p>For more information on the Java Persistence API, see

<a href="persistence-intro.html#BNBPZ">Chapter 40, "Introduction to the Java

Persistence API"</a>. For more information on the JSON Processing API, see

<a href="jsonp.html#GLRBB">Chapter 20, "JSON Processing"</a>.</p>

</div>

</div>

<h4 id="_the_call_records_chunk_step">The Call Records Chunk Step</h4>

<p>The first step is composed of the <code>CallRecordReader</code>,

<code>CallRecordProcessor</code>, and <code>CallRecordWriter</code> batch artifacts.</p>

</div>

<p>The <code>CallRecordReader</code> artifact reads call records from the log file:</p>

</div>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">@Dependent

@Named("CallRecordReader")

public class CallRecordReader implements ItemReader {

private ItemNumberCheckpoint checkpoint;

private String fileName;

private BufferedReader breader;

@Inject

JobContext jobCtx;

/* ... Override the open, close, readItem,

* and checkpointInfo methods ... */

}</code></pre>

</div>

<p>The <code>open</code> method reads the <code>log_filename</code> property and opens the log

file with a buffered reader:</p>

</div>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">fileName = jobCtx.getProperties().getProperty("log_file_name");

breader = new BufferedReader(new FileReader(fileName));</code></pre>

</div>

<p>If a checkpoint object is provided, the <code>open</code> method advances the

reader up to the last checkpoint. Otherwise, this method creates a new

checkpoint object. The checkpoint object keeps track of the line number

from the last committed chunk.</p>

</div>

<p>The <code>readItem</code> method returns a new <code>CallRecord</code> object or null at the

end of the log file:</p>

</div>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">@Override

public Object readItem() throws Exception {

/* Read a line from the log file and

* create a CallRecord from JSON */

String callEntryJson = breader.readLine();

if (callEntryJson != null) {

checkpoint.nextItem();

return new CallRecord(callEntryJson);

} else

return null;

}</code></pre>

</div>

<p>The <code>CallRecordProcessor</code> artifact obtains the airtime price from the

job properties, calculates the price of each call, and returns the call

object. This artifact overrides only the <code>processItem</code> method.</p>

</div>

<p>The <code>CallRecordWriter</code> artifact associates each call record with a bill

and stores the bill in the database. This artifact overrides the <code>open</code>,

<code>close</code>, <code>writeItems</code>, and <code>checkpointInfo</code> methods. The <code>writeItems</code>

method looks like this:</p>

</div>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">@Override

public void writeItems(List<Object> callList) throws Exception {

for (Object callObject : callList) {

CallRecord call = (CallRecord) callObject;

PhoneBill bill = em.find(PhoneBill.class, call.getFromNumber());

if (bill == null) {

/* No bill for this customer yet, create one */

bill = new PhoneBill(call.getFromNumber());

bill.addCall(call);

em.persist(bill);

} else {

/* Add call to existing bill */

bill.addCall(call);

}

}</code></pre>

</div>

</div>

<h4 id="_the_phone_billing_chunk_step">The Phone Billing Chunk Step</h4>

<p>The second step is composed of the <code>BillReader</code>, <code>BillProcessor</code>,

<code>BillWriter</code>, and <code>BillPartitionMapper</code> batch artifacts. This step gets

the phone bills from the database, computes the tax and total amount

due, and writes each bill to a text file. Since the processing of each

bill is independent of the others, this step can be partitioned and run

in more than one thread.</p>

</div>

<p>The <code>BillPartitionMapper</code> artifact specifies the number of partitions

and the parameters for each partition. In this example, the parameters

represent the range of items each partition should process. The artifact

obtains the number of bills in the database to calculate these ranges.

It provides a partition plan object that overrides the <code>getPartitions</code>

and <code>getPartitionProperties</code> methods of the <code>PartitionPlan</code> interface.

The <code>getPartitions</code> method looks like this:</p>

</div>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">@Override

public Properties[] getPartitionProperties() {

/* Assign an (approximately) equal number of elements

* to each partition. */

long totalItems = getBillCount();

long partItems = (long) totalItems / getPartitions();

long remItems = totalItems % getPartitions();

/* Populate a Properties array. Each Properties element

* in the array corresponds to a partition. */

Properties[] props = new Properties[getPartitions()];

for (int i = 0; i < getPartitions(); i++) {

props[i] = new Properties();

props[i].setProperty("firstItem",

String.valueOf(i * partItems));

/* Last partition gets the remainder elements */

if (i == getPartitions() - 1) {

props[i].setProperty("numItems",

String.valueOf(partItems + remItems));

} else {

props[i].setProperty("numItems",

String.valueOf(partItems));

}

return props;

}</code></pre>

</div>

<p>The <code>BillReader</code> artifact obtains the partition parameters as follows:</p>

</div>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">@Dependent

@Named("BillReader")

public class BillReader implements ItemReader {

@Inject @BatchProperty(name = "firstItem") private String firstItemValue; @Inject @BatchProperty(name = "numItems") private String numItemsValue;

private ItemNumberCheckpoint checkpoint; @PersistenceContext private EntityManager em; private Iterator iterator;

@Override

public void open(Serializable ckpt) throws Exception {

/* Get the range of items to work on in this partition */

long firstItem0 = Long.parseLong(firstItemValue);

long numItems0 = Long.parseLong(numItemsValue);

if (ckpt == null) {

/* Create a checkpoint object for this partition */

checkpoint = new ItemNumberCheckpoint();

checkpoint.setItemNumber(firstItem0);

checkpoint.setNumItems(numItems0);

} else {

checkpoint = (ItemNumberCheckpoint) ckpt;

}

/* Adjust range for this partition from the checkpoint */

long firstItem = checkpoint.getItemNumber();

long numItems = numItems0 - (firstItem - firstItem0);

...

}

...

}</code></pre>

</div>

<p>This artifact also obtains an iterator to read items from the JPA entity

manager:</p>

</div>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">/* Obtain an iterator for the bills in this partition */

String query = "SELECT b FROM PhoneBill b ORDER BY b.phoneNumber";

Query q = em.createQuery(query).setFirstResult((int) firstItem)

.setMaxResults((int) numItems);

iterator = q.getResultList().iterator();</code></pre>

</div>

<p>The <code>BillProcessor</code> artifact iterates over the list of call records in a

bill and calculates the tax and total amount due for each bill.</p>

</div>

<p>The <code>BillWriter</code> artifact writes each bill to a plain text file.</p>

</div>

</div>

<h4 id="_the_javaserver_faces_pages">The JavaServer Faces Pages</h4>

<p>The <code>index.xhtml</code> page contains a text area that shows the log file of

call records. The page provides a button for the user to submit the

batch job and navigate to the next page:</p>

</div>

<h1>The Phone Billing Example Application</h1>

<p>The batch job analyzes the following log file:</p>

<textarea cols="90" rows="25"

readonly="true">#{jsfBean.createAndShowLog()}</textarea>

<h:form>

<h:commandButton value="Start Batch Job"

action="#{jsfBean.startBatchJob()}" />

</h:form>

</body></code></pre>

</div>

<p>This page calls the methods of the managed bean to show the log file and

submit the batch job.</p>

</div>

<p>The <code>jobstarted.xhtml</code> page provides a button to check the current

status of the batch job and displays the bills when the job finishes:</p>

</div>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn"><p>Current Status of the Job: <b>#{jsfBean.jobStatus}</b></p>

<h:dataTable var="_row" value="#{jsfBean.rowList}"

border="1" rendered="#{jsfBean.completed}">

</h:dataTable>

<h:form>

<h:commandButton value="Check Status"

rendered="#{jsfBean.completed==false}"

action="jobstarted" />

</h:form></code></pre>

</div>

</div>

<h4 id="_the_managed_bean">The Managed Bean</h4>

<p>The <code>JsfBean</code> managed bean submits the job to the batch runtime, checks

on the status of the job, and reads the text files for each bill.</p>

</div>

<p>The <code>startBatchJob</code> method of the bean submits the job to the batch

runtime:</p>

</div>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">/* Submit the batch job to the batch runtime.

* JSF Navigation method (return the name of the next page) */

public String startBatchJob() {

jobOperator = BatchRuntime.getJobOperator();

execID = jobOperator.start("phonebilling", null);

return "jobstarted";

}</code></pre>

</div>

<p>The <code>getJobStatus</code> method of the bean checks the status of the job:</p>

</div>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">/* Get the status of the job from the batch runtime */

public String getJobStatus() {

return jobOperator.getJobExecution(execID).getBatchStatus().toString();

}</code></pre>

</div>

<p>The <code>getRowList</code> method of the bean creates a list of bills to be

displayed on the <code>jobstarted.xhtml</code> JSF page using a table.</p>

</div>

</div>

<h3 id="_running_the_phonebilling_example_application">Running the phonebilling Example Application</h3>

<p>You can use either NetBeans IDE or Maven to build, package, deploy, and

run the <code>phonebilling</code> example application.</p>

</div>

<p>The following topics are addressed here:</p>

</div>

<ul>

<li>

<p><a href="#BABIBBBG">To Run the phonebilling Example Application Using

NetBeans IDE</a></p>

</li>

<li>

<p><a href="#BABFHIIB">To Run the phonebilling Example Application Using

Maven</a></p>

</li>

</ul>

</div>

</div>

<h4 id="_to_run_the_phonebilling_example_application_using_netbeans_ide">To Run the phonebilling Example Application Using NetBeans IDE</h4>

<li>

<p>Make sure that GlassFish Server has been started (see

<a href="usingexamples002.html#BNADI">Starting and Stopping GlassFish

Server</a>).</p>

</li>

<li>

<p>From the File menu, choose Open Project.</p>

</li>

<li>

<p>In the Open Project dialog box, navigate to:</p>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">tut-install/examples/batch</code></pre>

</div>

</li>

<li>

<p>Select the <code>phonebilling</code> folder.</p>

</li>

<li>

<p>Click Open Project.</p>

</li>

<li>

<p>In the Projects tab, right-click the <code>phonebilling</code> project and

select Run.</p>

<p>This command builds and packages the application into a WAR file,

<code>phonebilling.war</code>, located in the <code>target/</code> directory; deploys it to

the server; and launches a web browser window at the following URL:</p>

</div>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">http://localhost:8080/phonebilling/</code></pre>

</div>

</li>

</ol>

</div>

</div>

<h4 id="_to_run_the_phonebilling_example_application_using_maven">To Run the phonebilling Example Application Using Maven</h4>

<li>

<p>Make sure that GlassFish Server has been started (see

<a href="usingexamples002.html#BNADI">Starting and Stopping GlassFish

Server</a>).</p>

</li>

<li>

<p>In a terminal window, go to:</p>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">tut-install/examples/batch/phonebilling/</code></pre>

</div>

</li>

<li>

<p>Enter the following command to deploy the application:</p>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">mvn install</code></pre>

</div>

</li>

<li>

<p>Open a web browser window at the following URL:</p>

<pre class="prettyprint highlight"><code class="language-oac_no_warn" data-lang="oac_no_warn">http://localhost:8080/phonebilling/</code></pre>

</div>

</li>

</ol>

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