4-Tier Model Client Tier Web Tier Business Tier EIS Tier

Run 4-Tier KWIC Project on J2EE Platform Preparation Packaging –Creating the J2EE Application (.ear) –Creating the Enterprise Bean (.jar) –Creating the Web Client (.war) Deploying Running

Preparation Set Environment Variables –JAVA_HOME = root directory of J2SE SDK installation –J2EE_HOME = root directory of J2EE SDK installation –PATH = %PATH%;%JAVA_HOME%\bin;%J2EE_HOME%\bin –CLASSPATH = %CLASSPATH%;%J2EE_HOME%\lib\j2ee.jar

Preparation Start Cloudscape database server. –C:\> cloudscape –start Start J2EE server –C:\> j2ee –verbose Start deploytool –C:\> deploytool Build the database table –C:\> cloudscape –isql WebAddressAccount urlName (PK) urlDescription

Packaging Create an Enterprise Archive (EAR) file –ProjectApp.ear Add Java Archive (JAR) files and Web Archive (WAR) files to the EAR –WebAddressAccountJAR: contains the enterprise bean files and related files –ProjectWAR: contains the Web Component files and related files

An enterprise bean is a server-side component that contains the business logic of an application Writes and compiles the source code Packages the bean’s classes into EJB JAR file –Remote Interface –Home Interface –Enterprise Bean Class Creating Enterprise Bean Remote Client Remote Interface Home Interface EJB

Remote Interface WebAddressAccount.java –defines the business methods that a client may call. The business methods are implemented in the enterprise bean code public interface WebAddressAccount extends EJBObject { public String getUrlName(); public String getUrlDescript(); }

Home Interface WebAddressAccountHome.java –defines the methods that allow a client to create, find, or remove an enterprise bean public interface WebAddressAccountHome extends EJBHome { public WebAddressAccount create(String urlName, String urlDescript); public WebAddressAccount findByPrimaryKey(String urlName) ; }

Enterprise Bean Class WebAddressAccountBean.java –implements the business methods public class WebAddressAccountBean implements EntityBean { public String getUrlName() { return urlName;} public String getUrlDescript() { return urlDescript; } public String ejbCreate( String urlName, String urlDescript) { insertRow( urlName, urlDescript); } public String ejbFindByPrimaryKey(String primaryKey) { result = selectByPrimaryKey(primaryKey); }

/*********************** Database Routines *************************/ private void makeConnection() { InitialContext ic = new InitialContext(); DataSource ds = (DataSource) ic.lookup(“java:comp/env/jdbc/WebAddressAccountDB”); con = ds.getConnection(); } private void insertRow ( String urlName, String urlDescript) { PreparedStatement prepStmt = con.prepareStatement("insert into webAddressaccount values ( ?, ? )"); prepStmt.setString(1, urlName); prepStmt.setString(2, urlDescript); prepStmt.executeUpdate(); prepStmt.close(); }

Creating Web Component When web client such as browser communicates with J2EE application, it dose so through server- side objects called Web components Writes and compiles the source code Bundles the.class,.jsp,.html files into WAR file

Source Codes URLListener.java URLEventObject.javaFindHandler.jsp Find.jsp KeyWordSearch.javaAlphabetizer.jsp Alphabetizer.javaCShiftLines.jspMenuFrame.html CShiftLines.javaSaveHandler.jspWelcome.html DetailURL.javaSave.jspindex.html JavaBeanJSPHTML SearchHistory.java

Web Client save.jsp CShiftLines.jsp saveHandle.jsp Alphabetizer.jsp find.jsp findHandle.jsp WebAddress AccountBean webaddressaccount DetailURL CShiftLine Alphabetizer KeyWordSearch SaveHistory Web Container EJB Container

JSP Syntax Include Declaration Scriptlet Expression

–Locating the home interface Object objRef = ic.lookup("java:comp/env/ejb/TheWebAddressAccount"); WebAddressAccountHome home = PortableRemoteObject.narrow(objRef, WebAddressAccountHome.class); –Creating an Enterprise Bean Instance WebAddressAccount joe = home.create( url_name, url_descript); –Invoking business methods WebAddressAccount findone = home.findByPrimaryKey(oneURLName); findone.getUrlDescript();

JNDI Names and Resource References JNDI: Java Naming and Directory Interface J2EE components locate objects by invoking the JNDI lookup method The JNDI name of a resource and the name of the resource reference are not the same This approach to naming requires that you map the two names before deployment

Specifying a Resource Reference The WebAddressAccountBean code refers to the database as follows: private String dbName = "java:comp/env/jdbc/WebAddressAccountDB";

Mapping Resource Reference to JNDI Name

Specifying a Resource Reference In lookup methods, the Web client refers to the home of an enterprise bean: Object objRef = ic.lookup("java:comp/env/ejb/TheWebAddressAccount ");

Mapping Resource Reference to JNDI Name

Deploying Select Tools -> Deploy In the JNDI Names dialog box, verify the names In the WAR Context Root dialog box, enter kwicProject in the Context Root field, which will be part of the URL

Running Change the default port number (8000) by editing the Config/web.properties file

Modifying the J2EE Application Change the source code Recompile it Redeploy the application –Select Tools -> Update Files –Select Tools -> Deploy Or –Select Tools -> Update And Redeploy