From 69ce3858383b063d6cb7e6a1ae3d085fc13759c5 Mon Sep 17 00:00:00 2001
From: Martin Goik <goik@hdm-stuttgart.de>
Date: Wed, 30 Mar 2016 21:19:26 +0200
Subject: [PATCH] Providing a complete persistence.xml rather than just a
fragment. Providing additional Maven dependencies
---
Doc/Persist/topics.xml | 130 +++++++++++++++++++++++++++++------------
1 file changed, 92 insertions(+), 38 deletions(-)
diff --git a/Doc/Persist/topics.xml b/Doc/Persist/topics.xml
index 1d888d1df..9559db9b6 100644
--- a/Doc/Persist/topics.xml
+++ b/Doc/Persist/topics.xml
@@ -103,35 +103,6 @@
<quote>Airline</quote>.</para>
</listitem>
- <listitem>
- <para><link
- xlink:href="http://techbus.safaribooksonline.com/book/programming/java/9781617290459/part-1dot-getting-started-with-orm/kindle_split_013_html">Chapter
- 2</link> of <xref linkend="bib_Bauer15"/> provides hints
- starting a project. Rather than using the described more
- elaborate <xref linkend="glo_JTA"/> based setup you may just
- want to follow a simpler <xref linkend="glo_JDBC"/> based
- approach when defining a persistence unit in your project's
- <filename>src/main/resources/META-INF/persistence.xml</filename>
- file:</para>
-
- <programlisting language="xml"><persistence... >
- <persistence-unit name="AirlinePU">
- ...
- <class>de.hdm_stuttgart.mi.persist.airline.model.Airline</class>
- <properties>
- <!-- JDBC database connection parameter (MI local MySQL installation) -->
- <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
- <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/hdm"/>
- <property name="javax.persistence.jdbc.user" value="hdmuser"/>
- <property name="javax.persistence.jdbc.password" value="XYZ"/>
- ...
-
- </properties>
- </persistence-unit>
- ...
-</persistence></programlisting>
- </listitem>
-
<listitem>
<para>Create an <classname>Airline</classname> <classname
xlink:href="http://docs.oracle.com/javaee/7/api/javax/persistence/Entity.html">@Entity</classname>
@@ -158,10 +129,93 @@ public class Airline {
protected Airline(){}
}</programlisting>
+ <para>The three imports require additional libraries to be
+ present. Using Maven this may be achieved by adding the
+ following dependency to your project's
+ <filename>pom.xml</filename> file:</para>
+
+ <programlisting language="xml"><dependency>
+ <groupId>org.hibernate</groupId>
+ <artifactId>hibernate-entitymanager</artifactId>
+ <version>5.1.0.Final</version>
+</dependency></programlisting>
+
<para>Why do we need <code>protected Airline(){}</code>
?</para>
</listitem>
+ <listitem>
+ <para><link
+ xlink:href="http://techbus.safaribooksonline.com/book/programming/java/9781617290459/part-1dot-getting-started-with-orm/kindle_split_013_html">Chapter
+ 2</link> of <xref linkend="bib_Bauer15"/> provides hints
+ starting a project. Rather than using the described more
+ elaborate <xref linkend="glo_JTA"/> based setup you may just
+ want to follow a simpler <xref linkend="glo_JDBC"/> based
+ approach when defining a persistence unit in your project's
+ <filename>src/main/resources/META-INF/persistence.xml</filename>
+ file:</para>
+
+ <programlisting language="xml"><persistence
+ version="2.1"
+ xmlns="http://xmlns.jcp.org/xml/ns/persistence"
+ xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+ xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence
+ http://www.oracle.com/webfolder/technetwork/jsc/xml/ns/persistence/persistence_2_1.xsd">
+
+ <!--
+ The <code>persistence.xml</code> file configures at least one persistence unit;
+ each unit must have a unique name.
+ -->
+ <persistence-unit name="AirlinePU">
+
+ <!-- A persistent unit has persistent (mapped) classes, you list them here. -->
+ <class>de.hdm_stuttgart.mi.persist.airline.model.Airline</class>
+
+ <!-- Hibernate can scan your classpath for mapped classes and add them automatically
+ to your persistence unit. This setting disables that feature. -->
+ <exclude-unlisted-classes>true</exclude-unlisted-classes>
+
+ <!-- Standard or vendor-specific options can be set as properties on a persistence unit.
+ Any standard properties have the <code>javax.persistence</code> name prefix, Hibernate's
+ settings use <code>hibernate</code> -->
+ <properties>
+ <!-- JDBC database connection parameter -->
+ <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
+ <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/hdm"/>
+ <property name="javax.persistence.jdbc.user" value="hdmuser"/>
+ <property name="javax.persistence.jdbc.password" value="XYZ"/>
+
+ <!-- The JPA engine should drop and re-create the SQL schema in the database
+ automatically when it boots. This is ideal for automated testing, when
+ you want to work with a clean database for every test run. -->
+ <property
+ name="javax.persistence.schema-generation.database.action"
+ value="drop-and-create"/>
+
+ <!-- When printing SQL in logs, let Hibernate format the SQL nicely and generate
+ comments into the SQL string so we know why Hibernate executed the SQL statement. -->
+ <property name="hibernate.format_sql" value="true"/>
+ <property name="hibernate.use_sql_comments" value="true"/>
+
+ <!-- Disable Hibernate scanning completely, we also don't want any hbm.xml files
+ discovered and added automatically. -->
+ <property name="hibernate.archive.autodetection" value="none"/>
+
+ </properties>
+ </persistence-unit>
+</persistence></programlisting>
+
+ <para>Our persistence unit connecting to a <xref
+ linkend="glo_Soft_Mysql"/> database server requires another
+ Maven dependency:</para>
+
+ <programlisting language="xml"><dependency>
+ <groupId>mysql</groupId>
+ <artifactId>mysql-connector-java</artifactId>
+ <version>5.1.38</version>
+</dependency></programlisting>
+ </listitem>
+
<listitem>
<para>Our <methodname>main()</methodname> class will just
write a single <classname>Airline</classname> instance to
@@ -250,9 +304,9 @@ mysql> show create table hibernate_sequence;
)</programlisting>
<para>On object creation the <xref linkend="glo_JPA"/> provider
- will use <code>hibernate_sequence</code> to generate
- <code>id</code> values. Thus the <xref
- linkend="glo_Soft_Mysql"/> <link
+ will use the additional <code>hibernate_sequence</code> table
+ for generating <code>id</code> values. Thus <xref
+ linkend="glo_Soft_Mysql"/>'s <link
xlink:href="http://dev.mysql.com/doc/refman/5.7/en/example-auto-increment.html">AUTO_INCREMENT</link>
feature is not yet being used.</para>
</answer>
@@ -269,8 +323,8 @@ mysql> show create table hibernate_sequence;
<qandadiv>
<qandaentry>
<question>
- <para>Modify the current class <classname>Airline</classname>
- to: like:</para>
+ <para>Modify the current <classname>Airline</classname>
+ class:</para>
<orderedlist>
<listitem>
@@ -445,12 +499,12 @@ public class Airline {
<listitem>
<para>Stable approach with respect to <xref
linkend="glo_Java"/> code refactoring: If e.g. the
- property <property>icaoCode</property> gets
+ <property>icaoCode</property> property gets
consistently renamed to
<property>icaoCode</property>Number <xref
- linkend="glo_SqlDdl"/> code will still be properly
- generated. However this problem may be overcome for
- our complex solution by providing stable <xref
+ linkend="glo_SqlDdl"/> code will still be generated
+ properly. However our complex solution may overcome
+ this problem by providing stable <xref
linkend="glo_SqlDdl"/> attribute names via
<code>@Column(name="icaoCode" ...)</code> thereby
protecting the database from unnecessary schema
--
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