Show me the
code
You can just download the zipped
Eclipse project
, add the required dependencies to the lib folder
under the /WebContent/WEB-INF/lib folder (relative to project's root folder) and
import it into Eclipse.
Prerequisites
Tomcat
Install Tomcat before going forward. See Tomcat's installation guide if you
have any problem installing it.
MySql
Install and configure MySql. Create a database named "quickstart" and run the
script below to create the "Person" table. Later, on applicationContext.xml,
we'll use 'root' as the user name and password for the database, remember to
replace those values with the right ones for your database.
CREATE TABLE 'quickstart'.'Person' (
'id' INTEGER UNSIGNED NOT NULL AUTO_INCREMENT,
'firstName' VARCHAR(45) NOT NULL,
'lastName' VARCHAR(45) NOT NULL,
PRIMARY KEY('id')
)
ENGINE = InnoDB;
Create
Eclipse project
- Open Eclipse. Seriously, you need to open Eclipse.
- Click File -> New -> Project. Under the "Web" folder, select "Dynamic
Web Project" and click "Next".
- Enter the project name, "quickstart" from here on. The project will be
running inside Tomcat, so we need to create a server configuration for it.
- Under "Target Runtime", click "New", select "Apache Tomcat 5.5" and click
next.
- Enter Tomcat's installation directory and select an installed JRE (1.5 is
required)
- Now you should be back to the project creation wizard, with Tomcat as your
Target Runtime. Click "Next". Select "Dynamic Web Module" and "Java" facets, and
click "Finish".
Dependencies
Your project should contain the folders "src", "build" and "WebContent". We
are going to put all the required jars under "/WebContent/WEB-INF/lib". To add
files to the "lib" folder, just copy them to
${workspace}\quickstart\WebContent\WEB-INF\lib, where ${workspace} is the
location of your Eclipse workspace folder. The version has been removed from the
jar files.
| Jar |
From |
| xwork.jar |
Struts 2 |
| struts2-api.jar |
Struts 2 |
| struts2-core.jar |
Struts 2 |
| struts2-Spring-plugin.jar |
Struts 2 |
| ognl.jar |
Struts 2 |
| freemarker-2.3.4.jar |
Struts 2 |
| mysql-connector-java.jar |
MySql JDBC Driver |
| spring.jar |
Sping 2.0 |
| antlr.jar |
Hibernate Core |
| asm.jar |
Hibernate Core |
| asm-attrs.jar |
Hibernate Core |
| cglib.jar |
Hibernate Core |
| dom4j.jar |
Hibernate Core |
| jdbc2_0-stdext.jar |
Hibernate Core |
| ehcache.jar |
Hibernate Core |
| hibernate3.jar |
Hibernate Core |
| xml-apis.jar |
Hibernate Core |
| commons-collections.jar |
Hibernate Core |
| ejb3-persistence.jar |
Hibernate Annotations |
| jta.jar |
Hibernate Annotations |
| hibernate-annotations.jar |
Hibernate Annotations |
| hibernate-entitymanager.jar |
Hibernate Entity Manager |
| javassist.jar |
Hibernate Entity Manager |
| jboss-archive-browsing.jar |
Hibernate Entity Manager |
Right click on the project and select "Refresh" (to notify Eclipse of the
jars that we just added).
Domain
Our domain model will consist of just a simple "Person" class with a couple
of fields.
- Create a new class named "Person" (File -> New -> Class), and enter
"quickstart.model" for the package name.
- Add the fields "id" (int), "firstName" (String), and lastName ("String")
with their setter/getter methods.
- Mark your class with the "@Entity" annotation, and the "id" field with the
annotations "@Id" and "@GeneratedValue".
your class will look like:
package quickstart.model;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
@Entity
public class Person {
@Id
@GeneratedValue
private Integer id;
private String lastName;
private String firstName;
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
}
@Entity will let the provider know that this class can be persisted. @Id
marks the "id" field as the primary key for this class. @GeneratedValue will
cause the id field to be generated by the provider (Hibernate). Classes and
fields are by default mapped to tables and columns with the same name, see JPA's
documentation for more details.
Person
service.
We will now write the class that will take care of CRUD operations on
"Person" objects.
- Create a new interface (File -> New -> Interface), enter
"PersonService" for the name, and "quickstart.service" for the namespace. Set
its content to:
package quickstart.service;
import java.util.List;
import quickstart.model.Person;
public interface PersonService {
public List<Person> findAll();
public void save(Person person);
public void remove(int id);
public Person find(int id);
}
- Create a new class (File -> New -> Class), enter "PersonServiceImpl"
for the name and "quickstart.service" for the namespace. Set its content to:
package quickstart.service;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;
import org.springframework.transaction.annotation.Transactional;
import quickstart.model.Person;
@Transactional
public class PersonServiceImpl implements PersonService {
private EntityManager em;
@PersistenceContext
public void setEntityManager(EntityManager em) {
this.em = em;
}
@SuppressWarnings("unchecked")
public List<Person> findAll() {
Query query = getEntityManager().createQuery("select p FROM Person p");
return query.getResultList();
}
public void save(Person person) {
if (person.getId() == null) {
em.persist(person);
} else {
em.merge(person);
}
}
public void remove(int id) {
Person person = find(id);
if (person != null) {
em.remove(person);
}
}
private EntityManager getEntityManager() {
return em;
}
public Person find(int id) {
return em.find(Person.class, id);
}
}
@PersistenceContext will make Spring inject an EntityManager into the service
when it is instantiated. The @PersistenceContext annotation can be placed on the
field, or on the setter method. If the class is annotated as @Transactional,
Spring will make sure that its methods run inside a transaction.
JPA
configuration
- Create a folder named "META-INF" under the "src" folder.
- Create a file named "persistence.xml" under the "META-INF" folder and set
its content to:
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"
version="1.0">
<persistence-unit name="punit">
</persistence-unit>
</persistence>
JPA configuration can be set on this file. On this example it will be empty
because the datasource configuration will be on the Spring configuration file.
Spring
- Update the content of web.xml under /WebContent/WEB-INF/web.xml to:
<?xml version="1.0" encoding="UTF-8"?>
<web-app id="person" version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
<display-name>person</display-name>
<filter>
<filter-name>struts2</filter-name>
<filter-class>
org.apache.struts2.dispatcher.FilterDispatcher
</filter-class>
</filter>
<filter-mapping>
<filter-name>struts2</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<listener>
<listener-class>
org.springframework.web.context.ContextLoaderListener
</listener-class>
</listener>
</web-app>
This will make the container redirect all requests to Struts
"FilterDispatcher" class. "index.jsp" is set as the home page, and Spring's
"ContextLoaderListener" is configured as a listener.
- Create a file named "applicationContext.xml" under /WebContent/WEB-INF, and
set its content to:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.0.xsd
http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.0.xsd">
<bean
class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" />
<bean id="personService" class="quickstart.service.PersonServiceImpl" />
<bean id="entityManagerFactory"
class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="dataSource" ref="dataSource" />
<property name="jpaVendorAdapter">
<bean
class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter">
<property name="database" value="MYSQL" />
<property name="showSql" value="true" />
</bean>
</property>
</bean>
<bean id="dataSource"
class="org.springframework.jdbc.datasource.DriverManagerDataSource">
<property name="driverClassName" value="com.mysql.jdbc.Driver" />
<property name="url" value="jdbc:mysql://localhost/test" />
<property name="username" value="root" />
<property name="password" value="root" />
</bean>
<bean id="transactionManager"
class="org.springframework.orm.jpa.JpaTransactionManager">
<property name="entityManagerFactory" ref="entityManagerFactory" />
</bean>
<tx:annotation-driven transaction-manager="transactionManager" />
<bean id="personAction" scope="prototype"
class="quickstart.action.PersonAction">
<constructor-arg ref="personService" />
</bean>
</beans>
Note that the "class" attribute of the bean "personAction" is set to the name
of the action class, and the "personService" bean will be passed as a parameter
to the action constructor. Change the "url", "username" and "password" in the
"dataSource" bean to the appropiate values for your database. For more details
on the rest of the beans on this file, see Spring's documentation. The "scope"
attribute is new in Spring 2, and it means that Spring will create a new
PersonAction object every time an object of that type is requested. In Struts 2
a new action object is created to serve each request, that's why we need
scope="prototype".
Struts
We will now create a simple Struts action that wraps PersonServices methods,
and we will configure Struts to use Spring as the object factory.
- Open the new class dialog (File -> New -> Class) and enter
"PersonAction" for the classname, and "quickstart.action" for the namespace. Set
its content to:
package quickstart.action;
import java.util.List;
import quickstart.model.Person;
import quickstart.service.PersonService;
import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.Preparable;
public class PersonAction implements Preparable {
private PersonService service;
private List<Person> persons;
private Person person;
private Integer id;
public PersonAction(PersonService service) {
this.service = service;
}
public String execute() {
this.persons = service.findAll();
return Action.SUCCESS;
}
public String save() {
this.service.save(person);
this.person = new Person();
return execute();
}
public String remove() {
service.remove(id);
return execute();
}
public List<Person> getPersons() {
return persons;
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public void prepare() throws Exception {
if (id != null)
person = service.find(id);
}
public Person getPerson() {
return person;
}
public void setPerson(Person person) {
this.person = person;
}
}
Look mom my action is a simple POJO!
The "Preparable" interface instructs
Struts to call the "prepare" method if the "PrepareInterceptor" is applied to
the action (by default, it is). The constructor of the action takes a
"PersonService" as a parameter, which Spring will take care of passing when the
action is instatiated.
- Create a new file named "struts.xml" under the "src" folder. And set its
content to:
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
"-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
"http://struts.apache.org/dtds/struts-2.0.dtd">
<struts>
<constant name="struts.objectFactory" value="spring" />
<constant name="struts.devMode" value="true" />
<package name="person" extends="struts-default">
<action name="list" method="execute" class="personAction">
<result>pages/list.jsp</result>
<result name="input">pages/list.jsp</result>
</action>
<action name="remove" class="personAction" method="remove">
<result>pages/list.jsp</result>
<result name="input">pages/list.jsp</result>
</action>
<action name="save" class="personAction" method="save">
<result>pages/list.jsp</result>
<result name="input">pages/list.jsp</result>
</action>
</package>
</struts>
Setting "struts.objectFactory" to "spring" will force Struts to instantiate
the actions using Spring, injecting all the defined dependencies on
applicationContext.xml. The "class" attribute for each action alias is set to
"personAction", which is the bean id that we defined on applicationContext.xml
for the PersonAction class. This is all that is needed to make Struts work with
Spring.
The pages
We only have two pages, "index.jsp" and "list.jsp". "list.jsp" returns a
table with a list of the persons on the database.We have this list on a
different page because we are going to add some AJAX to spicy it up.
- Create a new file named "list.jsp" under /WebContent/pages/ and set its
content to:
<%@ taglib prefix="s" uri="/struts-tags"%>
<p>Persons</p>
<s:if test="persons.size > 0">
<table>
<s:iterator value="persons">
<tr id="row_<s:property value="id"/>">
<td>
<s:property value="firstName" />
</td>
<td>
<s:property value="lastName" />
</td>
<td>
<s:url id="removeUrl" action="remove">
<s:param name="id" value="id" />
</s:url>
<s:a href="%{removeUrl}" theme="ajax" targets="persons">Remove</s:a>
<s:a id="a_%{id}" theme="ajax" notifyTopics="/edit">Edit</s:a>
</td>
</tr>
</s:iterator>
</table>
</s:if>
This is going to render a table with each row showing the first and last name
of the person, a link to remove the person, and a link to edit. The remove link
has the attribute "targets", set to "persons", which means that when the user
clicks on it, an asynchronous request will be made to the "remove" action (as
configured on struts.xml, "remove" points to the "remove" method in
PersonAction), passing the person id as parameter.
When the edit link is clicked on, it will publish the "/edit" topic, which
will trigger a javascript function to populate the fields.
- Create a new file named "index.jsp" under /WebContent and set its content
to:
<%@ taglib prefix="s" uri="/struts-tags"%>
<html>
<head>
<s:head theme="ajax" debug="true"/>
<script type="text/javascript">
dojo.event.topic.subscribe("/save", function(data, type, request) {
if(type == "load") {
dojo.byId("id").value = "";
dojo.byId("firstName").value = "";
dojo.byId("lastName").value = "";
}
});
dojo.event.topic.subscribe("/edit", function(data, type, request) {
if(type == "before") {
var id = data.split("_")[1];
var tr = dojo.byId("row_"+id);
var tds = tr.getElementsByTagName("td");
dojo.byId("id").value = id;
dojo.byId("firstName").value = dojo.string.trim(dojo.dom.textContent(tds[0]));
dojo.byId("lastName").value = dojo.string.trim(dojo.dom.textContent(tds[1]));
}
});
</script>
</head>
<body>
<s:url action="list" id="descrsUrl"/>
<div style="width: 300px;border-style: solid">
<div style="text-align: right;">
<s:a theme="ajax" notifyTopics="/refresh">Refresh</s:a>
</div>
<s:div id="persons" theme="ajax" href="%{descrsUrl}" loadingText="Loading..." listenTopics="/refresh"/>
</div>
<br/>
<div style="width: 300px;border-style: solid">
<p>Person Data</p>
<s:form action="save" validate="true">
<s:textfield id="id" name="person.id" cssStyle="display:none"/>
<s:textfield id="firstName" label="First Name" name="person.firstName"/>
<s:textfield id="lastName" label="Last Name" name="person.lastName"/>
<s:submit theme="ajax" targets="persons" notifyTopics="/save"/>
</s:form>
</div>
</body>
</html>
Look mom no page refresh!
The div "persons" will load its content
asynchronously, and will show "Loading..." while while the request is on
progress (you can use the "indicator" attribute for better progress feedback),
you can force it to refresh clicking on the "Refresh" link. The "submit" button,
will make an asynchronous request to the action "save" ("save" method on
PersonAction), and will publish the topic "/save" to which we subscribed to,
using "dojo.event.topic.subscribe", to clear the input fields.
Validation
Because we don't want any John Doe on our database, we will add some basic
client side validation to our form. In Struts 2, validation can be placed on xml
files with the name pattern ActionName-validation.xml, located on the same
package as the action. To add validation to an specific alias of an action (like
a method), the validation file name follows the pattern
ActionName-alias-validation.xml, where "alias" is the action alias name (in this
case a method name, "save"). Add a file named "PersonAction-save-validation.xml"
under /src/quickstart/action, and set its content to:
<!DOCTYPE validators PUBLIC
"-//OpenSymphony Group//XWork Validator 1.0//EN"
"http://www.opensymphony.com/xwork/xwork-validator-1.0.2.dtd">
<validators>
<field name="person.firstName">
<field-validator type="requiredstring">
<message>First name is required!</message>
</field-validator>
</field>
<field name="person.lastName">
<field-validator type="requiredstring">
<message>Last name is required!</message>
</field-validator>
</field>
</validators>
See the Struts documentation for details on existing validators, and how to
write, and plug in, your own validators.
To run the project, Right click on your project and Run As -> Run on
Server. You can debug it on the same way, Right click on the project and Debug
As -> Debug on Server. Download and install Struts 2 Showcase to see more
examples.
posted on 2008-12-11 00:55
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