From 8b3bccca75ae36f836d28ab725cf963c10a9486e Mon Sep 17 00:00:00 2001
From: goik <goik@hdm-stuttgart.de>
Date: Sun, 17 Feb 2013 20:14:55 +0100
Subject: [PATCH] type mapping modification
---
Doc/course.xml | 58 ++++++++++++++++++-
.../java/hibintro/v9/PersistSingleUser.java | 33 +++++++++++
.../src/main/java/hibintro/v9/User.java | 47 +++++++++++++++
.../main/java/hibintro/v9/hibernate.cfg.xml | 17 ++++++
4 files changed, 154 insertions(+), 1 deletion(-)
create mode 100644 ws/eclipse/HibIntro/src/main/java/hibintro/v9/PersistSingleUser.java
create mode 100644 ws/eclipse/HibIntro/src/main/java/hibintro/v9/User.java
create mode 100644 ws/eclipse/HibIntro/src/main/java/hibintro/v9/hibernate.cfg.xml
diff --git a/Doc/course.xml b/Doc/course.xml
index 7e4104ee0..3399a7007 100644
--- a/Doc/course.xml
+++ b/Doc/course.xml
@@ -16484,7 +16484,63 @@ public class User {
<section xml:id="sectChangeDefaultTypeMapping">
<title>Changing the default type mapping</title>
- <para/>
+ <para>Sometimes we are interested in changing <abbrev
+ xlink:href="http://www.javaworld.com/javaworld/jw-01-2008/jw-01-jpa1.html">JPA</abbrev>'s
+ default type mapping strategy. For example <trademark
+ xlink:href="http://www.mysql.com/about/legal/trademark.html">Mysql</trademark>
+ versions prior to 5.0 lack an appropriate type representing boolean
+ values. It was therefore quite common mapping boolean properties to
+ <code>CHAR(1)</code> with possible values being <code>'Y'</code> and
+ <code>'N'</code>. Hibernate will map boolean values to
+ <code>tinyint(1)</code>. Supporting older software may require to
+ tweak the standard mapping.</para>
+
+ <para>Unfortunately <abbrev
+ xlink:href="http://www.javaworld.com/javaworld/jw-01-2008/jw-01-jpa1.html">JPA</abbrev>
+ itself does not offer any interface for this purpose. The
+ persistence provider may offer a solution though. Hibernate for
+ example allows to remap <coref linkend="remapBooleanChar"/> types .
+ We assume our <classname>hibintro.v9.User</classname> class to have
+ a <code>boolean</code> property <code>active</code>:</para>
+
+ <informaltable border="1">
+ <colgroup width="6%"/>
+
+ <colgroup width="94%"/>
+
+ <tr>
+ <td valign="top"><emphasis role="bold">Java</emphasis></td>
+
+ <td valign="top"><programlisting>package hibintro.v9;
+...
+public class User {
+...
+ public void setCname(String cname) {this.cname = cname;}
+
+ boolean active = false;
+ @Type(type="yes_no") <co xml:id="remapBooleanChar"/>
+ public boolean isActive() {return active;}
+ public void setActive(boolean active) {this.active = active;}
+}</programlisting></td>
+ </tr>
+
+ <tr>
+ <td valign="top"><emphasis role="bold">Sql</emphasis></td>
+
+ <td><programlisting>CREATE TABLE User (
+ uidNumber int(11) NOT NULL PRIMARY KEY,
+ active char(1) NOT NULL,
+ cname varchar(255) DEFAULT NULL,
+ uid varchar(255) NOT NULL
+)</programlisting></td>
+ </tr>
+ </informaltable>
+
+ <para>Readers being interested in more sophisticated strategies like
+ mapping user defined datatypes to database types are advised to read
+ the <link
+ xlink:href="http://docs.jboss.org/hibernate/orm/4.1/manual/en-US/html/ch05.html#mapping-types">manual
+ section on Hibernate types</link>.</para>
</section>
</section>
diff --git a/ws/eclipse/HibIntro/src/main/java/hibintro/v9/PersistSingleUser.java b/ws/eclipse/HibIntro/src/main/java/hibintro/v9/PersistSingleUser.java
new file mode 100644
index 000000000..1ce093231
--- /dev/null
+++ b/ws/eclipse/HibIntro/src/main/java/hibintro/v9/PersistSingleUser.java
@@ -0,0 +1,33 @@
+package hibintro.v9;
+
+import hibintro.util.HibernateUtil;
+
+import org.hibernate.Session;
+import org.hibernate.Transaction;
+
+/**
+ * @author goik
+ *
+ * Persisting a simple instance of {@link User}
+ *
+ */
+public class PersistSingleUser {
+
+ /**
+ * @param args not used.
+ */
+ public static void main(String[] args) {
+ final Session session = HibernateUtil.createSessionFactory("hibintro/v9/hibernate.cfg.xml").openSession();
+
+ final Transaction transaction = session.beginTransaction();
+ {
+ final User u = new User();
+ u.setUidNumber(123);
+ u.setUid("goik");
+ u.setCname("Martin Goik");
+
+ session.save(u);
+ }
+ transaction.commit();
+ }
+}
\ No newline at end of file
diff --git a/ws/eclipse/HibIntro/src/main/java/hibintro/v9/User.java b/ws/eclipse/HibIntro/src/main/java/hibintro/v9/User.java
new file mode 100644
index 000000000..0cd019f04
--- /dev/null
+++ b/ws/eclipse/HibIntro/src/main/java/hibintro/v9/User.java
@@ -0,0 +1,47 @@
+package hibintro.v9;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+
+import org.hibernate.annotations.Type;
+
+/**
+ * @author goik
+ *
+ * {@link User} instances with re-mapped boolean property
+ */
+@Entity
+public class User {
+
+ int uidNumber;
+ @Id
+ public int getUidNumber() {return uidNumber;}
+ public void setUidNumber(int uidNumber) {this.uidNumber = uidNumber;}
+
+ String uid;
+ /**
+ * @return The user's unique login name e.g. "goik"
+ */
+ @Column(nullable=false)
+ public String getUid() {return uid;}
+ /**
+ * @param uid See {@link #getUid()}.
+ */
+ public void setUid(String uid) {this.uid = uid;}
+
+ String cname;
+ /**
+ * @return The user's common name e.g. "Martin Goik"
+ */
+ public String getCname() {return cname;}
+ /**
+ * @param cname See {@link #getCname()}.
+ */
+ public void setCname(String cname) {this.cname = cname;}
+
+ boolean active = false;
+ @Type(type="yes_no")
+ public boolean isActive() {return active;}
+ public void setActive(boolean active) {this.active = active;}
+}
\ No newline at end of file
diff --git a/ws/eclipse/HibIntro/src/main/java/hibintro/v9/hibernate.cfg.xml b/ws/eclipse/HibIntro/src/main/java/hibintro/v9/hibernate.cfg.xml
new file mode 100644
index 000000000..e4caa9fa7
--- /dev/null
+++ b/ws/eclipse/HibIntro/src/main/java/hibintro/v9/hibernate.cfg.xml
@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
+ "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
+<hibernate-configuration>
+ <session-factory >
+ <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
+ <property name="hibernate.connection.password">XYZ</property>
+ <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hdm</property>
+ <property name="hibernate.connection.username">hdmuser</property>
+ <property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
+ <property name="hibernate.show_sql">true</property>
+ <property name="hibernate.format_sql">true</property>
+ <property name="hibernate.hbm2ddl.auto">update</property>
+
+ <mapping class="hibintro.v9.User"/>
+ </session-factory>
+</hibernate-configuration>
--
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