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HibernateRelationshi...




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At line 2 changed 1 line.
This is a tutorial to show how to create and manage Hibernate relationships within [AppFuse]. This tutorial was written for AppFuse 1.8 and the AppGen pieces may not work with previous versions.
This is a tutorial to show how to create and manage Hibernate relationships within [AppFuse]. This tutorial was written using AppFuse 1.8.2. All of the code for this tutorial is downloadable at [http://static.appfuse.org/downloads/appfuse-hr.zip].
At line 4 changed 1 line.
;:''For further details about the specifics regarding creating entities, XDoclet tags for Hibernate, DAO development, etc., please refer to [Creating new DAOs and Objects in AppFuse|CreateDAO].''
;:''For further details about the specifics regarding creating objects, XDoclet tags for Hibernate, DAO development, etc., please refer to [Creating new DAOs and Objects in AppFuse|CreateDAO].''
At line 6 added 2 lines.
%%note __NOTE:__ Copying the Java code in this tutorials [doesn't work in Firefox|http://raibledesigns.com/page/rd?anchor=java2html_plugin_for_jspwiki_causes]. A workaround is to CTRL+Click (Command+Click on OS X) the code block and then copy it.%%
At line 7 changed 2 lines.
* [1] Create Weblog.java, Entry.java and add XDoclet tags
* [2] [[Many-to-One] Create a new Category object and modify Entry.java to use it
* [1] Create Weblog.java, Entry.java and Category.java domain objects
* [2] [[Many-to-Many] A Weblogs can have many Users, a User can have many Weblogs
At line 10 changed 3 lines.
* [4] [[Many-to-Many] ???
* [5] Lazy-Loading Issues
* [6] Managing relationships and indexed properties in the UI
* [4] [[Many-to-One] A Category object can be assigned to many entries
At line 15 removed 2 lines.
For our purposes, the Weblog entity is a list of available weblogs. A “Weblog” object has the following properties – an id, a username (for the user who created the blog), a dateCreated, and a blogTitle. Every Entry object has an id, a text, and a timeCreated property.
The first thing to do is create some objects to persist. Let's create both a "Weblog" object and an “Entry” object (in the src/dao/**/model directory). Basic XDoclet tags for these entities are show as well.
At line 18 changed 1 line.
[{Java2HtmlPlugin
The ''Weblog'' object is used to indentify a person's blog. This class has the following properties:
At line 20 changed 1 line.
package org.appfuse.model;
* weblogId
* blogTitle
* dateCreated
At line 22 changed 1 line.
import java.util.Date;
The ''Entry'' object is used to contain a listing of a person's blog entries in their Weblog. This class contains the following properties:
At line 24 changed 4 lines.
import org.apache.commons.lang.builder.EqualsBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;
import org.apache.commons.lang.builder.ToStringBuilder;
import org.apache.commons.lang.builder.ToStringStyle;
* entryId
* text
* timeCreated
At line 29 changed 4 lines.
/**
* @hibernate.class table="weblog"
*/
public class Weblog extends BaseObject {
%%note __NOTE:__ The primary keys are prefixed with their entity name to avoid confusion. I generally recommend using "id" for your entities, but wanted to make thing clearer in this tutorial.%%
At line 34 changed 5 lines.
private Long weblogId;
private String username;
private Date dateCreated;
private String blogTitle;
private Integer version;
Below is a class diagram of these two objects, as well as the others you'll create in this tutorial.
At line 40 changed 8 lines.
/**
* @return Returns the blogTitle.
*
* @hibernate.property column="blog_title"
*/
public String getBlogTitle() {
return blogTitle;
}
[ER-Diagram.jpg]
At line 49 changed 7 lines.
/**
* @param blogTitle
* The blogTitle to set.
*/
public void setBlogTitle(String blogTitle) {
this.blogTitle = blogTitle;
}
The first thing you need to do in this tutorial is these two object to persist. Create a __Weblog.java__ class and an __Entry.java__ class (in the src/dao/**/model directory). The necessary XDoclet tags for these entities is included on the ''getter'' method's javadoc. You can download these files using the links below. Note that javadocs have been eliminated for brevity.
At line 57 changed 8 lines.
/**
* @return Returns the dateCreated.
*
* @hibernate.property column="date_created"
*/
public Date getDateCreated() {
return dateCreated;
}
* [Download Weblog.java|Weblog.java]
* [Download Entry.java|Entry.java]
At line 66 changed 7 lines.
/**
* @param dateCreated
* The dateCreated to set.
*/
public void setDateCreated(Date dateCreated) {
this.dateCreated = dateCreated;
}
;:''Rather than fill up this tutorial with large blocks of Java code, the necessary files are attached and linked to. Small code snippets are used where appropriate. You should be able to easily download the files by right-clicking on them and selecting "Save Target As...".''
At line 74 changed 9 lines.
/**
* @return Returns the id.
*
* @hibernate.id column="weblog_id" generator-class="native"
* unsaved-value="null"
*/
public Long getWeblogId() {
return weblogId;
}
Create a __Category.java__ object to act as an entity for persisting category information about weblog entries. Each category can have many entries. This class contains the following properties:
At line 84 changed 7 lines.
/**
* @param id
* The id to set.
*/
public void setWeblogId(Long weblogId) {
this.weblogId = weblogId;
}
* categoryId
* name
* description
At line 92 changed 8 lines.
/**
* @return Returns the username.
*
* @hibernate.property column="username"
*/
public String getUsername() {
return username;
}
* [Download Category.java|Category.java]
At line 101 changed 7 lines.
/**
* @param username
* The username to set.
*/
public void setUsername(String username) {
this.username = username;
}
!Configure Spring
At line 109 changed 8 lines.
/**
* @return Returns the version.
*
* @hibernate.version
*/
public Integer getVersion() {
return version;
}
Add the 3 new mapping files (that will be generated) to the "sessionFactory" bean's ''mappingResources'' property in __src/org/appfuse/dao/hibernate/applicationContext-hibernate.xml__.
At line 118 changed 7 lines.
/**
* @param version
* The version to set.
*/
public void setVersion(Integer version) {
this.version = version;
}
[{Java2HtmlPlugin
At line 126 changed 13 lines.
/**
* @see java.lang.Object#equals(Object)
*/
public boolean equals(Object object) {
if (!(object instanceof Weblog)) {
return false;
}
Weblog rhs = (Weblog) object;
return new EqualsBuilder().append(this.blogTitle, rhs.blogTitle)
.append(this.username, rhs.username).append(this.dateCreated,
rhs.dateCreated).append(this.weblogId, rhs.weblogId).append(
this.version, rhs.version).isEquals();
}
<property name="mappingResources">
<list>
<value>org/appfuse/model/Role.hbm.xml</value>
<value>org/appfuse/model/User.hbm.xml</value>
<value>org/appfuse/model/Weblog.hbm.xml</value>
<value>org/appfuse/model/Entry.hbm.xml</value>
<value>org/appfuse/model/Category.hbm.xml</value>
</list>
</property>
}]
At line 140 changed 8 lines.
/**
* @see java.lang.Object#hashCode()
*/
public int hashCode() {
return new HashCodeBuilder(2066507029, -390167195).append(
this.blogTitle).append(this.username).append(this.dateCreated)
.append(this.weblogId).append(this.version).toHashCode();
}
!![[Many-to-Many] A Weblogs can have many Users, a User can have many Weblogs [#2]
At line 149 changed 11 lines.
/**
* @see java.lang.Object#toString()
*/
public String toString() {
return new ToStringBuilder(this, ToStringStyle.MULTI_LINE_STYLE)
.append("id", this.weblogId).append("version", this.version).append(
"username", this.username).append("blogTitle",
this.blogTitle).append("dateCreated", this.dateCreated)
.toString();
}
}
A Weblog can have many Users. Basically the idea is of a shared weblog that is a place where many users can express themselves about a particular topic of interest. For this bit of functionality the User object will be modified to have a many-to-many relationship with Weblog.
At line 161 changed 1 line.
}]
Add the following ''users'' property and accessor methods to __Weblog.java__.
At line 165 changed 1 line.
package org.appfuse.model;
private List users = new ArrayList();
/**
* @hibernate.bag table="weblog_user" cascade="save-update" lazy="true"
* @hibernate.collection-key column="weblog_id"
* @hibernate.collection-many-to-many class="org.appfuse.model.User" column="username"
*/
public List getUsers() {
return users;
}
At line 167 changed 1 line.
import java.util.Date;
public void addUser(User user) {
getUsers().add(user);
}
At line 169 changed 4 lines.
import org.apache.commons.lang.builder.EqualsBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;
import org.apache.commons.lang.builder.ToStringBuilder;
import org.apache.commons.lang.builder.ToStringStyle;
public void setUsers(List users) {
this.users = users;
}
}]
At line 174 changed 3 lines.
/**
* @hibernate.class table="entry"
*/
%%note __NOTE:__ The reason a java.util.List is used instead of a java.util.Set is because this is because [Sets aren't supported for indexed properties in Struts|http://www.mail-archive.com/[email protected]/msg26289.html].%%
At line 96 added 1 line.
!User modifications
At line 98 added 1 line.
To allow navigation from a User objec to a list of Weblogs, you need to add a List of Weblogs to the User object. Modify ''User.java'' to add a ''weblogs'' List and accessor methods.
At line 180 changed 1 line.
public class Entry extends BaseObject {
[{Java2HtmlPlugin
At line 182 changed 4 lines.
private Long id;
private String text;
private Date timeCreated;
private Integer version;
protected List weblogs;
At line 187 changed 4 lines.
/*
* Generate your getters and setters using your favorite IDE: In Eclipse:
* Right-click -> Source -> Generate Getters and Setters
*/
/**
* @hibernate.bag table="weblog_user" cascade="save-update" lazy="true"
* @hibernate.collection-key column="username"
* @hibernate.collection-many-to-many class="org.appfuse.model.Weblog" column="weblog_id"
*/
public List getWeblogs() {
return weblogs;
}
At line 192 changed 102 lines.
/**
* @return Returns the id.
*
* @hibernate.id column="entry_id" generator-class="native"
* unsaved-value="null"
*/
public Long getEntryId() {
return entryId;
}
/**
* @param id
* The id to set.
*/
public void setEntryId(Long entryId) {
this.entryId = entryId;
}
/**
* @return Returns the text.
*
* @hibernate.property column="entry_text"
*/
public String getText() {
return text;
}
/**
* @param text
* The text to set.
*/
public void setText(String text) {
this.text = text;
}
/**
* @return Returns the timeCreated.
*
* @hibernate.property column="time_created"
*/
public Date getTimeCreated() {
return timeCreated;
}
/**
* @param timeCreated
* The timeCreated to set.
*/
public void setTimeCreated(Date timeCreated) {
this.timeCreated = timeCreated;
}
/**
* @return Returns the version.
*
* @hibernate.version
*/
public Integer getVersion() {
return version;
}
/**
* @param version
* The version to set.
*/
public void setVersion(Integer version) {
this.version = version;
}
/**
* @see java.lang.Object#equals(Object)
*/
public boolean equals(Object object) {
if (!(object instanceof Entry)) {
return false;
}
Entry rhs = (Entry) object;
return new EqualsBuilder().append(this.text, rhs.text).append(
this.timeCreated, rhs.timeCreated).append(this.id, rhs.id)
.append(this.version, rhs.version).isEquals();
}
/**
* @see java.lang.Object#hashCode()
*/
public int hashCode() {
return new HashCodeBuilder(-880342185, -1668369001).append(this.text)
.append(this.timeCreated).append(this.id).append(this.version)
.toHashCode();
}
/**
* @see java.lang.Object#toString()
*/
public String toString() {
return new ToStringBuilder(this, ToStringStyle.MULTI_LINE_STYLE)
.append("text", this.text).append("id", this.id).append(
"version", this.version).append("timeCreated",
this.timeCreated).toString();
}
}
public void setWeblogs(List weblogs) {
this.weblogs = weblogs;
}
At line 118 added 1 line.
!Test it!
At line 120 added 1 line.
Create a unit test so you can verify that everything actually works. Create a __WeblogDaoTest__ class in your test/dao/**/dao directory. This file should extend GenericDaoTest. If you're using anything less than AppFuse 1.9, you may have to modify GenericDAOTest's "dao" variable so its __protected__ instead of private. Copy the code below into this test:
At line 298 removed 5 lines.
!![[Many-to-One] Create a new Category object and modify Entry.java to use it [#2]
A category object will act as an entity for persisting category information about weblog entries. A category object will consist of an id (primary key), category name, and a description. Each category can have many entries.
At line 305 changed 1 line.
package org.appfuse.model;
package org.appfuse.dao;
At line 307 changed 4 lines.
import org.apache.commons.lang.builder.EqualsBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;
import org.apache.commons.lang.builder.ToStringBuilder;
import org.apache.commons.lang.builder.ToStringStyle;
import java.util.Date;
At line 312 changed 4 lines.
/**
* @hibernate.class table="category"
*/
public class Category extends BaseObject {
import org.appfuse.model.User;
import org.appfuse.model.Weblog;
At line 317 changed 107 lines.
private Long id;
private String categoryName;
private String categoryDescription;
private Integer version;
/**
* @return Returns the categoryDescription.
*
* @hibernate.property column="category_description"
*/
public String getCategoryDescription() {
return categoryDescription;
}
/**
* @param categoryDescription
* The categoryDescription to set.
*/
public void setCategoryDescription(String categoryDescription) {
this.categoryDescription = categoryDescription;
}
/**
* @return Returns the categoryName.
*
* @hibernate.property column="category_name"
*/
public String getCategoryName() {
return categoryName;
}
/**
* @param categoryName
* The categoryName to set.
*/
public void setCategoryName(String categoryName) {
this.categoryName = categoryName;
}
/**
* @return Returns the id.
*
* @hibernate.id column="category_id" generator-class="native"
* unsaved-value="null"
*/
public Long getId() {
return id;
}
/**
* @param id
* The id to set.
*/
public void setId(Long id) {
this.id = id;
}
/**
* @return Returns the version.
*
* @hibernate.version
*/
public Integer getVersion() {
return version;
}
/**
* @param version
* The version to set.
*/
public void setVersion(Integer version) {
this.version = version;
}
/**
* @see java.lang.Object#equals(Object)
*/
public boolean equals(Object object) {
if (!(object instanceof Category)) {
return false;
}
Category rhs = (Category) object;
return new EqualsBuilder().append(this.categoryDescription,
rhs.categoryDescription).append(this.categoryName,
rhs.categoryName).append(this.id, rhs.id).append(this.version,
rhs.version).isEquals();
}
/**
* @see java.lang.Object#hashCode()
*/
public int hashCode() {
return new HashCodeBuilder(-837614407, -1874103513).append(
this.categoryDescription).append(this.categoryName).append(
this.id).append(this.version).toHashCode();
}
/**
* @see java.lang.Object#toString()
*/
public String toString() {
return new ToStringBuilder(this, ToStringStyle.MULTI_LINE_STYLE)
.append("id", this.id)
.append("categoryName", this.categoryName).append("version",
this.version).append("categoryDescription",
this.categoryDescription).toString();
}
public class WeblogDaoTest extends GenericDAOTest {
public void testWeblogAndUsers() throws Exception {
Weblog w = new Weblog();
w.setBlogTitle("My New Weblog");
w.setDateCreated(new Date());
// add it to the database
dao.saveObject(w);
w = (Weblog) dao.getObject(Weblog.class, w.getWeblogId());
assertTrue(w.getUsers().isEmpty());
// add a user
User u = (User) dao.getObject(User.class, "mraible");
w.addUser(u);
dao.saveObject(w);
w = (Weblog) dao.getObject(Weblog.class, w.getWeblogId());
assertTrue(w.getUsers().size() == 1);
// remove the user
w.setUsers(null);
dao.saveObject(w);
w = (Weblog) dao.getObject(Weblog.class, w.getWeblogId());
assertNull(w.getUsers());
}
At line 425 removed 1 line.
At line 428 changed 1 line.
The many-to-one relationship between entry and category can be established by the entity classes. Hibernate relatioships can typically be established on either side of the relationship or as a bi-directional one as well. For our purposes,this relationship will be maintained by an extra property and collection held by Entry.
Make sure you run __ant setup-db__ before running __ant test-dao -Dtestcase=UserDAO__. When running the test, you'll probably get a ''LazyInitializationException''. To solve this, change BaseDaoTestCase to extend Spring's [AbstractTransactionalDataSourceSpringContextTests|http://www.springframework.org/docs/api/org/springframework/test/AbstractTransactionalDataSourceSpringContextTests.html] if it doesn't already. In additional, you'll need to make a few changes to the existing tests so all the tests pass. [Here is a patch|LazyDaoTests.diff]. At a minimum, you'll need to fix BaseDAOTestCase and GenericDAOTest (onSetUp() -> onSetupBeforeTransaction()).
At line 168 added 2 lines.
Because the WeblogDaoTest is now extending AbstractTransactionalDataSourceSpringContextTests (ATDSSCT), there is a "jdbcTemplate" variable you can use to do additional querying. For instance, you could add the following at the end of your ''testWeblogAndUsers()'' method:
At line 432 changed 170 lines.
package org.appfuse.model;
import java.util.Date;
import org.apache.commons.lang.builder.EqualsBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;
import org.apache.commons.lang.builder.ToStringBuilder;
import org.apache.commons.lang.builder.ToStringStyle;
/**
* @hibernate.class table="entry"
*/
public class Entry extends BaseObject {
private Long entryId;
private String text;
private Date timeCreated;
private Integer version;
private Long categoryId;
private Category category;
/*
* Generate your getters and setters using your favorite IDE: In Eclipse:
* Right-click -> Source -> Generate Getters and Setters
*/
/**
* @return Returns the category.
*
* @hibernate.many-to-one insert="false" update="false" cascade="none"
* column="category_id" outer-join="true"
*/
public Category getCategory() {
return category;
}
/**
* @param category
* The category to set.
*/
public void setCategory(Category category) {
this.category = category;
}
/**
* @return Returns the categoryId.
*
* @hibernate.property column="category_id"
*/
public Long getCategoryId() {
return categoryId;
}
/**
* @param categoryId
* The categoryId to set.
*
*/
public void setCategoryId(Long categoryId) {
this.categoryId = categoryId;
}
/**
* @return Returns the id.
*
* @hibernate.id column="entry_id" generator-class="native"
* unsaved-value="null"
*/
public Long getEntryId() {
return entryId;
}
/**
* @param id
* The id to set.
*/
public void setEntryId(Long entryId) {
this.entryId = entryId;
}
/**
* @return Returns the text.
*
* @hibernate.property column="entry_text"
*/
public String getText() {
return text;
}
/**
* @param text
* The text to set.
*/
public void setText(String text) {
this.text = text;
}
/**
* @return Returns the timeCreated.
*
* @hibernate.property column="time_created"
*/
public Date getTimeCreated() {
return timeCreated;
}
/**
* @param timeCreated
* The timeCreated to set.
*/
public void setTimeCreated(Date timeCreated) {
this.timeCreated = timeCreated;
}
/**
* @return Returns the version.
*
* @hibernate.version
*/
public Integer getVersion() {
return version;
}
/**
* @param version
* The version to set.
*/
public void setVersion(Integer version) {
this.version = version;
}
/**
* @see java.lang.Object#equals(Object)
*/
public boolean equals(Object object) {
if (!(object instanceof Entry)) {
return false;
}
Entry rhs = (Entry) object;
return new EqualsBuilder().append(this.text, rhs.text).append(
this.timeCreated, rhs.timeCreated).append(this.category,
rhs.category).append(this.entryId, rhs.entryId).append(
this.categoryId, rhs.categoryId).append(this.version,
rhs.version).isEquals();
}
/**
* @see java.lang.Object#hashCode()
*/
public int hashCode() {
return new HashCodeBuilder(835056587, 1192670387).append(this.text)
.append(this.timeCreated).append(this.category).append(
this.entryId).append(this.categoryId).append(
this.version).toHashCode();
}
/**
* @see java.lang.Object#toString()
*/
public String toString() {
return new ToStringBuilder(this, ToStringStyle.MULTI_LINE_STYLE)
.append("text", this.text).append("entryId", this.entryId)
.append("version", this.version).append("categoryId",
this.categoryId).append("category", this.category)
.append("timeCreated", this.timeCreated).toString();
}
}
String qry = "select count(*) from weblog_user where username = 'mraible' " +
" and weblog_id = " + w.getWeblogId();
assertEquals(0, jdbcTemplate.queryForInt(qry));
At line 606 changed 1 line.
Modify the Weblog object and Entry object to represent the multiplicity of a weblog can have many entries. This relationship ship is set on the Weblog class using a list. Hibernate tags are used to establish this relationship using a bag as the Hibernate collection type.
Now you'll modify the __Weblog__ object and __Entry__ object to represent the multiplicity of a weblog that can have many entries. This relationship is set on the Weblog class using a java.util.List. XDoclet tags are used to establish this relationship using a __bag__ as the Hibernate collection type. Add the following code to your __Weblog.java__ class.
At line 610 changed 1 line.
package org.appfuse.model;
private List entries;
At line 612 changed 1 line.
import java.util.Date;
/**
* @return Returns the entries.
*
* @hibernate.bag name="entries" lazy="false" cascade="all"
* @hibernate.collection-key column="weblog_id"
* @hibernate.collection-one-to-many class="org.appfuse.model.Entry"
*/
public List getEntries() {
return entries;
}
At line 614 changed 165 lines.
import java.util.List;
import org.apache.commons.lang.builder.EqualsBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;
import org.apache.commons.lang.builder.ToStringBuilder;
import org.apache.commons.lang.builder.ToStringStyle;
/**
* @hibernate.class table="weblog"
*/
public class Weblog extends BaseObject {
private Long weblogId;
private String username;
private Date dateCreated;
private String blogTitle;
private Integer version;
private List entries;
/**
* @return Returns the blogTitle.
*
* @hibernate.property column="blog_title"
*/
public String getBlogTitle() {
return blogTitle;
}
/**
* @param blogTitle
* The blogTitle to set.
*/
public void setBlogTitle(String blogTitle) {
this.blogTitle = blogTitle;
}
/**
* @return Returns the dateCreated.
*
* @hibernate.property column="date_created"
*/
public Date getDateCreated() {
return dateCreated;
}
/**
* @param dateCreated
* The dateCreated to set.
*/
public void setDateCreated(Date dateCreated) {
this.dateCreated = dateCreated;
}
/**
* @return Returns the entries.
*
* @hibernate.bag name="entries" lazy="true" inverse="true"
* cascade="delete"
* @hibernate.collection-key column="entry_id"
* @hibernate.collection-one-to-many
* class="org.appfuse.model.Entry"
*/
public List getEntries() {
return entries;
}
/**
* @param entries
* The entries to set.
*/
public void setEntries(List entries) {
this.entries = entries;
}
/**
* @return Returns the id.
*
* @hibernate.id column="weblog_id" generator-class="native"
* unsaved-value="null"
*/
public Long getWeblogId() {
return weblogId;
}
/**
* @param id
* The id to set.
*/
public void setWeblogId(Long weblogId) {
this.weblogId = weblogId;
}
/**
* @return Returns the username.
*
* @hibernate.property column="username"
*/
public String getUsername() {
return username;
}
/**
* @param username
* The username to set.
*/
public void setUsername(String username) {
this.username = username;
}
/**
* @return Returns the version.
*
* @hibernate.version
*/
public Integer getVersion() {
return version;
}
/**
* @param version
* The version to set.
*/
public void setVersion(Integer version) {
this.version = version;
}
/**
* @see java.lang.Object#equals(Object)
*/
public boolean equals(Object object) {
if (!(object instanceof Weblog)) {
return false;
}
Weblog rhs = (Weblog) object;
return new EqualsBuilder().append(this.blogTitle, rhs.blogTitle)
.append(this.weblogId, rhs.weblogId).append(this.username,
rhs.username).append(this.entries, rhs.entries).append(
this.dateCreated, rhs.dateCreated).append(this.version,
rhs.version).isEquals();
}
/**
* @see java.lang.Object#hashCode()
*/
public int hashCode() {
return new HashCodeBuilder(-1412256665, -696169811).append(
this.blogTitle).append(this.weblogId).append(this.username)
.append(this.entries).append(this.dateCreated).append(
this.version).toHashCode();
}
/**
* @see java.lang.Object#toString()
*/
public String toString() {
return new ToStringBuilder(this, ToStringStyle.MULTI_LINE_STYLE)
.append("weblogId", this.weblogId).append("version",
this.version).append("username", this.username).append(
"blogTitle", this.blogTitle).append("entries",
this.entries).append("dateCreated", this.dateCreated)
.toString();
}
}
public void setEntries(List entries) {
this.entries = entries;
}
At line 781 changed 1 line.
The Entry class is modified slightly to provide a placeholder for the relationships between Weblog and Entry.
Modify the __Entry__ class is so it contains a foreign key to its parent __Weblog__ class.
At line 785 changed 1 line.
package org.appfuse.model;
private Long weblogId;
At line 787 changed 1 line.
import java.util.Date;
/**
* @hibernate.property column="weblog_id"
*/
public Long getWeblogId() {
return weblogId;
}
At line 789 changed 4 lines.
import org.apache.commons.lang.builder.EqualsBuilder;
import org.apache.commons.lang.builder.HashCodeBuilder;
import org.apache.commons.lang.builder.ToStringBuilder;
import org.apache.commons.lang.builder.ToStringStyle;
public void setWeblogId(Long weblogId) {
this.weblogId = weblogId;
}
}]
At line 794 changed 4 lines.
/**
* @hibernate.class table="entry"
*/
public class Entry extends BaseObject {
At this point, you could add an additional test method to WeblogDaoTest to test that this relationship works. Of course, you'll need to run __ant setup-db__ to make sure your database knows about the relationship.
At line 799 changed 6 lines.
private Long entryId;
private String text;
private Date timeCreated;
private Integer version;
private Category category;
private Long categoryId;
!![[Many-to-One] A Category object can be assigned to many entries [#4]
At line 223 added 1 line.
The ''many-to-one'' relationship between __Category__ and __Entry__ can be established using XDoclet tags. Hibernate relationships can be established on either side of the relationship or bi-directionally. For this tutorial, this relationship is maintained by a __categoryId__ property and a __Category__ object in __Entry__. The list of possible categories for a weblog entry will eventually be represented as a drop-down on the UI. Add the following code to your __Entry.java__ class. Notice that the relationship to __Category__ has ''insert="false" update="false"''. This is because the object is read-only. This can be useful for displaying a category's name on the UI when you're viewing an Entry.
At line 807 changed 1 line.
private Long weblogId;
[{Java2HtmlPlugin
At line 809 changed 4 lines.
/*
* Generate your getters and setters using your favorite IDE: In Eclipse:
* Right-click -> Source -> Generate Getters and Setters
*/
private Long categoryId;
private Category category;
At line 814 changed 9 lines.
/**
* @return Returns the category.
*
* @hibernate.many-to-one insert="false" update="false" cascade="none"
* column="category_id" outer-join="true"
*/
public Category getCategory() {
return category;
}
/**
* @hibernate.many-to-one insert="false" update="false" cascade="none"
* column="category_id" outer-join="true"
*/
public Category getCategory() {
return category;
}
At line 824 changed 7 lines.
/**
* @param category
* The category to set.
*/
public void setCategory(Category category) {
this.category = category;
}
public void setCategory(Category category) {
this.category = category;
}
At line 832 changed 8 lines.
/**
* @return Returns the categoryId.
*
* @hibernate.property column="category_id"
*/
public Long getCategoryId() {
return categoryId;
}
/**
* @hibernate.property column="category_id"
*/
public Long getCategoryId() {
return categoryId;
}
At line 841 changed 133 lines.
/**
* @param categoryId
* The categoryId to set.
*
*/
public void setCategoryId(Long categoryId) {
this.categoryId = categoryId;
}
/**
* @return Returns the id.
*
* @hibernate.id column="entry_id" generator-class="native"
* unsaved-value="null"
*/
public Long getEntryId() {
return entryId;
}
/**
* @param id
* The id to set.
*/
public void setEntryId(Long entryId) {
this.entryId = entryId;
}
/**
* @return Returns the text.
*
* @hibernate.property column="entry_text"
*/
public String getText() {
return text;
}
/**
* @param text
* The text to set.
*/
public void setText(String text) {
this.text = text;
}
/**
* @return Returns the timeCreated.
*
* @hibernate.property column="time_created"
*/
public Date getTimeCreated() {
return timeCreated;
}
/**
* @param timeCreated
* The timeCreated to set.
*/
public void setTimeCreated(Date timeCreated) {
this.timeCreated = timeCreated;
}
/**
* @return Returns the version.
*
* @hibernate.version
*/
public Integer getVersion() {
return version;
}
/**
* @param version
* The version to set.
*/
public void setVersion(Integer version) {
this.version = version;
}
/**
* @return Returns the weblogId.
*
* @hibernate.property column="weblog_id"
*/
public Long getWeblogId() {
return weblogId;
}
/**
* @param weblogId
* The weblogId to set.
*/
public void setWeblogId(Long weblogId) {
this.weblogId = weblogId;
}
/**
* @see java.lang.Object#equals(Object)
*/
public boolean equals(Object object) {
if (!(object instanceof Entry)) {
return false;
}
Entry rhs = (Entry) object;
return new EqualsBuilder().append(this.text, rhs.text).append(
this.timeCreated, rhs.timeCreated).append(this.weblogId,
rhs.weblogId).append(this.category, rhs.category).append(
this.entryId, rhs.entryId).append(this.categoryId,
rhs.categoryId).append(this.version, rhs.version).isEquals();
}
/**
* @see java.lang.Object#hashCode()
*/
public int hashCode() {
return new HashCodeBuilder(-1879789101, 535224049).append(this.text)
.append(this.timeCreated).append(this.weblogId).append(
this.category).append(this.entryId).append(
this.categoryId).append(this.version).toHashCode();
}
/**
* @see java.lang.Object#toString()
*/
public String toString() {
return new ToStringBuilder(this, ToStringStyle.MULTI_LINE_STYLE)
.append("weblogId", this.weblogId).append("text", this.text)
.append("entryId", this.entryId)
.append("version", this.version).append("categoryId",
this.categoryId).append("category", this.category)
.append("timeCreated", this.timeCreated).toString();
}
}
public void setCategoryId(Long categoryId) {
this.categoryId = categoryId;
}
At line 976 changed 1 line.
!![[Many-to-Many] ??? [#4]
After making these changes, your __WeblogDaoTest__ should still pass. Verify it does by running __ant setup-db test-dao -Dtestcase=Weblog__.
At line 978 changed 1 line.
The Weblog system that we are developing allows one additional bit of functionality. A particular Weblog can have many Users. Basically the idea is of a shared weblog that is a place where many users can express themselves about a particular topic of interest. For this bit of functionality the User object will be modified to have a many-to-many relationship with Weblog.
''__Yeah baby, Yeah!__''
%%(color: green)
BUILD SUCCESSFUL\\
Total time: 24 seconds
%%
At line 980 changed 1 line.
!!Lazy-Loading Issues [#5]
Before working on the UI, it's helpful to have some sample data so you don't have to do manual data entry. Add the following XML to the bottom of __metadata/sql/sample-data.xml__.
At line 982 changed 1 line.
!!Managing relationships and indexed properties in the UI [#6]
<div style="color: blue !important; margin-left: 50px">
{{{
<table name='weblog'>
<column>weblog_id</column>
<column>blog_title</column>
<column>date_created</column>
<row>
<value>1</value>
<value><![CDATA[Sponge Bob is Cool]]></value>
<value>2004-03-31</value>
</row>
<row>
<value>2</value>
<value><![CDATA[Java Development = Fun]]></value>
<value>2005-01-05</value>
</row>
</table>
<table name='weblog_user'>
<column>weblog_id</column>
<column>username</column>
<row>
<value>1</value>
<value>tomcat</value>
</row>
<row>
<value>1</value>
<value>mraible</value>
</row>
<row>
<value>2</value>
<value>mraible</value>
</row>
</table>
<table name='category'>
<column>category_id</column>
<column>name</column>
<column>description</column>
<row>
<value>1</value>
<value><![CDATA[Struts vs. Spring MVC]]></value>
<value><![CDATA[Comparing implementations of the MVC Design Pattern]]></value>
</row>
<row>
<value>2</value>
<value><![CDATA[Cycling Notes]]></value>
<value><![CDATA[All about cycling in the US.]]></value>
</row>
<row>
<value>3</value>
<value><![CDATA[Cyclocross]]></value>
<value><![CDATA[Bog Trotters Unite!]]></value>
</row>
</table>
<table name='entry'>
<column>entry_id</column>
<column>entry_text</column>
<column>time_created</column>
<column>weblog_id</column>
<column>category_id</column>
<row>
<value>1</value>
<value><![CDATA[Testing]]></value>
<value>2005-04-11 01:02:03.4</value>
<value>1</value>
<value>1</value>
</row>
<row>
<value>2</value>
<value><![CDATA[Test Value]]></value>
<value>2005-04-12 01:02:03.4</value>
<value>1</value>
<value>1</value>
</row>
<row>
<value>3</value>
<value><![CDATA[Test Value 3]]></value>
<value>2005-04-12 01:02:03.4</value>
<value>2</value>
<value>3</value>
</row>
</table>
}}}
</div>
At line 348 added 3 lines.
----
''Next Up:'' __Part II:__ [Create Weblog UI|HibernateRelationshipsUI] - Creating a UI to manage the relationships created in this tutorial.

Back to HibernateRelationships, or to the Page History.