Post Subject : Tutorial on JBossIDE EJB3.0 Tools
Ref. 1 : JBoss IDE TrailBlazer : Hike 1 - EJB 3.0 Tools
http://trailblazer.demo.jboss.com/IDETrail/
=== Environment in use;
- Windows XP SP2
- JDK 1.5.0_05
- JBoss AS 4.0.3SP1
- JBoss IDE1.5RC1 + Eclipse 3.1.1
Following notes/findings cover only Task 5 below;
Task 1: Download and install JDK 1.5
Task 2: Install JBoss AS 4.0.3SP1 using the installer
Task 3: Download and install JBoss IDE1.5RC1 and Eclipse3.1.1
Task 4: Configure Eclipse and JBossIDE to control JBoss AS
Task 5: Carry out a tutorial (Ref. 1)
- Ref. 1 contains following trails;
Trail 1: Create an EJB 3.0 Project
Trail 2: Create EJB 3.0 Entity Beans
Trail 3: Create EJB 3.0 Session Beans
Trail 4: Create a Java Servlet
Trail 5: Package an EJB 3.0 Application
Trail 6: Deploy and Debug
Trail 1: Create an EJB 3.0 Project
- follow the trail in Ref. 1
= jump over "Create a JBoss configuration" link since it has been configured at Task 4 in the last post of this thread.
- on completion of the project named "articles", confirm following point before proceeding further steps.
= in the Eclipse Package Explorer, the JRE System Library path is to be "[jdk 1.5]", not "(C:\)"[jre 1.5.0_05]" (see Task 1. in the last post)
= if not, change the library location as follow;
= right-click the project "articles" in the Package Explorer.
= then, go to "Properties > Java Build Path > Libraries > JRE System Library > Edit... > Installed JREs... > Edit..."
= in "Edit JRE" box;
* JRE name --> jdk 1.5
* JRE home directory --> C:\jdk1.5.0_05\jre
= click "OK"...
Trail 2: Create EJB 3.0 Entity Beans
- create "Article.java" and "Author.java" as per the trail in Ref. 1
- type "@E" then "Ctrl+space" for the code assist, a pop-up menu shows a list of annotations.
- select "@Entity"
= note1: If no "@Entity",
* right-click the project "articles" in the Eclipse Package Explorer (left top).
* then go to "Properties > Java Build Path > Libraries (tag) > Add External JARs..."
* add "ejb3-persistence.jar" under "..\server\all\deploy\ejb3.deployer".
= note2: Creation of the class "Author" (in Article.java)
* place the mouse cursor on "Author", then "Ctrl+1" (or right-click "light-bulb") to show "Quick Fix"
= note3: "Organize Imports" for "Collection" (in Author.java)
* place the mouse cursor on "Collection"
* then "Ctrl+Shift+O" to show "Organize Imports"
* (or right-click "light-bulb", then Quick Fix)
Trail 3: Create EJB 3.0 Session Beans
- create "Authors.java" and "AuthorsBean.java" as per the trail in Ref. 1
- in "AuthorsBean.java", use "@PersistenceContext" instead of "@Inject".
Ref.: "A problem with @Injected EntityManager"
http://www.jboss.org/index.html?module=bb&op=viewtopic&t=66949
Trail 4: Create a Java Servlet
- add "J2EE 1.4Libraries (JBoss-IDE)" and
- create "AuthorServlet.java" as per the trail in Ref. 1
= note1: On completion of the servlet, descriptions in "Problems" tag in the Eclipse workbench might show;
Problem : "The serializable class AuthorServlet does not declare a static final serialVersionUID field of type long"
AuthorServlet.java articles/src/org/jboss/ejb3demo/web line xx
* if the problem occur,
* place mouse cursor on "AuthorServlet", then "Ctl+1".
* select and double-click "Add default serial version ID"
* a set of codes below is added at the top and the problem will be gone.
/**
*
*/
private static final long serialVersionUID = 1L;
= note2: Apply same process as Note1 to following classes, if necessary;
* class "Article" in "Article.java"
* class "Author" in "Author.java"
Trail 5: Package an EJB 3.0 Application - as per the steps in Ref. 1
Trail 6: Deploy and Debug - start "Debug" session to start JBoss AS and deploy .ejb3 and .war files as per the steps in Ref. 1
- go to URL "http://localhost:8080/authors/authors" and see the results.
= they might be as follows (error);
HTTP Status 500 -
-----------------------------------------------------------------------------------------
type Exception report
message
description The server encountered an internal error () that prevented it from fulfilling
this request.
exception
java.lang.reflect.UndeclaredThrowableException
$Proxy83.addAuthor(Unknown Source)
org.jboss.ejb3demo.web.AuthorServlet.createArticles(AuthorServlet.java:57)
org.jboss.ejb3demo.web.AuthorServlet.doPost(AuthorServlet.java:50)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
javax.servlet.http.HttpServlet.service(HttpServlet.java:810)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:81)
note The full stack trace of the root cause is available in the Apache Tomcat/5.5 logs.
------------------------------------------------------------------------------------------
Apache Tomcat/5.5
- if so, modify "Articles.java" and "Author.java" (not "Authors.java")
Ref.: "JBoss EJB3.0 tutorial problems and solutions"
http://www.jboss.org/index.html?module=bb&op=viewtopic&t=69256 In "Articles.java";
add : import java.io.Serializable;
change : public class Article {... --> public class Article implements Serializable {...
In "Author.java";
add : import java.io.Serializable;
change : public class Author {... --> public class Author implements Serializable {...- then, re-packaging and re-deploy them.
= note1: re-deploy both of .ejb3 and .war files even if revision is one side only, otherwise the results might not come properly.
= note2: a few repetition might be necessary to get the results. Repeat un-deploy/re-packaging/re-deploy if no success.
= In "server.log" file, following part seems to be a set of characteristic messages of ejb3/hibernate in case of normal process.
:
2005-11-06 15:31:46,440 DEBUG [org.jboss.ejb3.entity.ManagedEntityManagerFactory] GETTING NEW ...
2005-11-06 15:31:46,440 DEBUG [org.jboss.ejb3.entity.ManagedEntityManagerFactory] logLived...
2005-11-06 15:31:46,440 DEBUG [org.jboss.ejb3.entity.ManagedEntityManagerFactory] LONG LIVED ...
2005-11-06 15:31:46,440 DEBUG [org.hibernate.impl.SessionImpl] opened session at timestamp: ...
2005-11-06 15:31:46,440 DEBUG [org.hibernate.impl.SessionImpl] find: from Author
2005-11-06 15:31:46,440 DEBUG [org.hibernate.engine.QueryParameters] named parameters: {}
2005-11-06 15:31:46,440 DEBUG [org.hibernate.hql.ast.QueryTranslatorImpl] parse() - HQL: from ...
2005-11-06 15:31:46,450 DEBUG [org.hibernate.hql.ast.AST] --- HQL AST ---
\-[QUERY] 'query'
\-[SELECT_FROM] 'SELECT_FROM'
\-[FROM] 'from'
\-[RANGE] 'RANGE'
\-[DOT] '.'
+-[DOT] '.'
| +-[DOT] '.'
| | +-[IDENT] 'org'
| | \-[IDENT] 'jboss'
| \-[IDENT] 'ejb3demo'
\-[IDENT] 'Author'
2005-11-06 15:31:46,450 DEBUG [org.hibernate.hql.ast.ErrorCounter] throwQueryException() : ...
2005-11-06 15:31:46,460 DEBUG [org.hibernate.hql.antlr.HqlSqlBaseWalker] select << begin ...
2005-11-06 15:31:46,460 DEBUG [org.hibernate.hql.ast.tree.FromElement] FromClause{level=1} ...
2005-11-06 15:31:46,460 DEBUG [org.hibernate.hql.antlr.HqlSqlBaseWalker] select : finishing ...
2005-11-06 15:31:46,460 DEBUG [org.hibernate.hql.ast.HqlSqlWalker] processQuery() : ( SELECT ...
2005-11-06 15:31:46,460 DEBUG [org.hibernate.hql.ast.HqlSqlWalker] Derived SELECT clause created.
2005-11-06 15:31:46,460 DEBUG [org.hibernate.hql.ast.util.JoinProcessor] Using FROM fragment ...
2005-11-06 15:31:46,460 DEBUG [org.hibernate.hql.antlr.HqlSqlBaseWalker] select >> end ...
2005-11-06 15:31:46,470 DEBUG [org.hibernate.hql.ast.AST] --- SQL AST ---
\-[SELECT] QueryNode: 'SELECT' querySpaces (AUTHORS)
+-[SELECT_CLAUSE] SelectClause: '{derived select clause}'
| +-[SELECT_EXPR] SelectExpressionImpl: 'author0_.authorId as authorId9_' {FromElement{...
| \-[SQL_TOKEN] SqlFragment: 'author0_.name as name9_'
\-[FROM] FromClause: 'from' FromClause{level=1, fromElementCounter=1, fromElements=1, ...
\-[FROM_FRAGMENT] FromElement: 'AUTHORS author0_' FromElement{explicit,not a collection ...
2005-11-06 15:31:46,470 DEBUG [org.hibernate.hql.ast.ErrorCounter] throwQueryException() : ...
2005-11-06 15:31:46,470 DEBUG [org.hibernate.hql.ast.QueryTranslatorImpl] HQL: from org.jboss...
2005-11-06 15:31:46,470 DEBUG [org.hibernate.hql.ast.QueryTranslatorImpl] SQL: select author0_...
2005-11-06 15:31:46,470 DEBUG [org.hibernate.hql.ast.ErrorCounter] throwQueryException() : ...
:= in "HSQL Database Manager", type "select * from ARTICLES" to confirm the records.
ARTICLEID TITLE BODY AUTHORID
--------------------------------------------------------------------
1 marshall's 1st article this is an article 1
2 marshall's 2nd article this is also article 2
3 max's 1st article this is an article 3
4 max's 2nd article this is also article 4
= for "AUTHORS";
AUTHORID NAME
-------------------
1 Marshall
2 Marshall
3 Max
4 Max
=== Ref. On completion of the trails, the files are as follow;
Article.java
package org.jboss.ejb3demo;
import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratorType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;
@Entity
@Table(name = "ARTICLES")
public class Article implements Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
private int articleId;
private String title;
private String body;
private Author author;
@Id (generate = GeneratorType.AUTO)
@Column (name = "articleId")
public int getArticleId() {
return articleId;
}
public void setArticleId(int articleId) {
this.articleId = articleId;
}
@ManyToOne
@JoinColumn (name = "authorId")
public Author getAuthor() {
return author;
}
public void setAuthor(Author author) {
this.author = author;
}
public String getBody() {
return body;
}
public void setBody(String body) {
this.body = body;
}
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
}Authors.java
package org.jboss.ejb3demo;
import java.util.List;
import javax.ejb.Remote;
@Remote
public interface Authors {
public List<Author> getAllAuthors();
public Author addAuthor (String name);
public void addArticle (Author author, String title, String body);
}AuthorsBean.java
package org.jboss.ejb3demo;
import javax.ejb.Stateless;
import java.util.ArrayList;
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.Query;
public @Stateless class AuthorsBean implements Authors {
@PersistenceContext
private EntityManager manager;
public void addArticle(Author author, String title, String body) {
manager.persist(author);
author.addArticle(title, body);
}
public Author addAuthor(String name) {
Author author = new Author();
author.setName(name);
return author;
}
public List<Author> getAllAuthors() {
ArrayList<Author> authors = new ArrayList<Author>();
Query q = manager.createQuery("from Author");
for (Object o : q.getResultList())
{
authors.add((Author) o);
}
return authors;
}
}Author.java
package org.jboss.ejb3demo;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratorType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.OneToMany;
import javax.persistence.Table;
@Entity
@Table(name = "AUTHORS")
public class Author implements Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
private int authorId;
private String name;
private Collection<Article> articles;
@OneToMany (cascade = CascadeType.ALL, fetch = FetchType.EAGER, mappedBy = "author")
@JoinColumn (name = "authorId")
public Collection<Article> getArticles() {
return articles;
}
public void setArticles(Collection<Article> articles) {
this.articles = articles;
}
@Id(generate = GeneratorType.AUTO)
@Column (name = "authorId")
public int getAuthorId() {
return authorId;
}
public void setAuthorId(int authorId) {
this.authorId = authorId;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public void addArticle(String title, String body) {
if (articles == null)
articles = new ArrayList<Article>();
Article article = new Article();
article.setAuthor(this);
article.setBody(body);
article.setTitle(title);
articles.add(article);
}
}AuthorServlet.java
package org.jboss.ejb3demo.web;
import java.io.IOException;
import java.io.PrintWriter;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.jboss.ejb3demo.Article;
import org.jboss.ejb3demo.Author;
import org.jboss.ejb3demo.Authors;
public class AuthorServlet extends HttpServlet {
/**
*
*/
private static final long serialVersionUID = 1L;
private Authors authorsBean;
public void init() throws ServletException {
try {
Context context = new InitialContext();
authorsBean =(Authors) context.lookup(Authors.class.getName());
} catch (NamingException e) {
e.printStackTrace();
}
}
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
doPost(req, resp);
}
protected void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
String mode = req.getParameter("mode");
if (mode == null)
mode = "show";
if (mode.equals("show"))
{
showArticles(req, resp);
}
else if (mode.equals("create"))
{
createArticles(req, resp);
}
}
private void createArticles(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException
{
Author marshall = authorsBean.addAuthor("Marshall");
Author max = authorsBean.addAuthor("Max");
authorsBean.addArticle(marshall, "marshall's 1st article", "this is an article");
authorsBean.addArticle(marshall, "marshall's 2nd article", "this is also an article");
authorsBean.addArticle(max, "max's 1st article", "this is an article");
authorsBean.addArticle(max, "max's 2nd article", "this is also an article");
showArticles(req, resp);
}
private void showArticles(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException
{
PrintWriter out = resp.getWriter();
for (Author author : authorsBean.getAllAuthors())
{
for (Article article : author.getArticles())
{
out.println("<b>" + article.getTitle() + "</b>" + " by <i>" + author.getName() + "</i><br/>");
out.println(" " + article.getBody() + "<br/><br/>");
}
}
out.println("<form method=\"POST\" action=\"authors\">");
out.println("<input type=\"hidden\" name=\"mode\" value=\"create\">");
out.println("<input type=\"submit\" value=\"Create articles\">");
out.println("</form>");
}
}web.xml
<?xml version="1.0" encoding="UTF-8"?>
<web-app 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">
<servlet>
<servlet-name>AuthorServlet</servlet-name>
<servlet-class>org.jboss.ejb3demo.web.AuthorServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>AuthorServlet</servlet-name>
<url-pattern>/authors</url-pattern>
</servlet-mapping>
</web-app>
packaging-build.xml
<?xml version="1.0" encoding="UTF-8"?>
<project name="Packaging Generator" default="_packaging_generation_">
<target name="_packaging_generation_" depends="N65540,N65557"/>
<target name="N65540" description="authors-beans.ejb3">
<jar destfile="authors-beans.ejb3">
<zipfileset dir="bin" excludes="**/*Servlet.java"/>
</jar>
</target>
<target name="N65557" description="authors.war">
<jar destfile="authors.war">
<zipfileset dir="src" prefix="WEB-INF">
<include name="web.xml"/>
</zipfileset>
<zipfileset dir="bin" prefix="WEB-INF/classes" includes="**/*Servlet.java"/>
</jar>
</target>
</project>
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