customerlistbean.java

此程序都是企业级 的数据库开发程序 全面揭示了JAVA对数据库的操作

package mvc.custlist;

/* Standard Java class package */
import java.rmi.RemoteException;
import java.io.File;
import java.util.Collection;
import java.util.Iterator;

/* Pulled from the J2EE or JBoss servlet.jar */
import javax.servlet.http.HttpServletRequest;

/* Pulled from the J2EE or JBoss ejb.jar */
import javax.naming.InitialContext;
import javax.ejb.SessionContext;

/* Classes pulled from the xerces.jar */
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.apache.xerces.dom.DocumentImpl;

import mvc.templates.*;
import mvc.*;
import mvc.entitybeans.customers.*;
import mvc.entitybeans.postalcodes.*;


public class CustomerListBean implements MVCBean {

  /*
   * The retrieve method for the CustomerListBean retrieves all of the customers
   * and their addresses from the Music Record database.  The data is
   * packaged as XML and returned to the application invoking the CustomerList
   * EJB.
   */
  public Document retrieve(HttpServletRequest _request) 
          throws RemoteException, Exception {

    InitialContext ctx = new InitialContext();
    CustomersHome customersHome = (CustomersHome) ctx.lookup("Customers");

    Collection customersCollections = customersHome.findAll();

    /* Building the XML Document that contains the customerRS data */
    Document xmlDocReturned = buildXML(customersCollections, ctx);

    return xmlDocReturned;
  } 

  /*
   * The post() method is returning null because the CustomerList screen
   * does not actually save any data.
   */
  public Document post(HttpServletRequest _request) 
          throws RemoteException, Exception {
    return null;
  } 

  /*
   * The buildXML method builds an XML document containing the customer
   * address data retrieved from the music record database.
   */
  private Document buildXML(Collection _customerCollections, 
                            InitialContext _ctx) throws Exception {
    Document xmlDoc = new DocumentImpl();

    /* Creating the rootElement */
    Element rootElement = xmlDoc.createElement("CUSTOMERS");
    Element customerElement = xmlDoc.createElement("CUSTOMER");

    xmlDoc.appendChild(rootElement);

    Iterator iterator = _customerCollections.iterator();

    /* Cycling through all of the records within the resultset */
    while (iterator.hasNext()) {

      /* Retrieve my customer object from my iterator */
      Customers customer = (Customers) iterator.next();

      /* Setting up my primary key for my customer order */
      customerElement.setAttribute("customerid", 
                                   customer.getCustomerId().toString());

      /* Adding my different elements to the order header */
      customerElement.appendChild(MVCHelper.buildDBElement(xmlDoc, 
              "CUSTOMERFIRSTNAME", customer.getCustomerFirstName()));
      customerElement.appendChild(MVCHelper.buildDBElement(xmlDoc, 
              "CUSTOMERLASTNAME", customer.getCustomerLastName()));
      customerElement.appendChild(MVCHelper.buildDBElement(xmlDoc, 
              "CUSTOMERADDRESS1", customer.getCustomerAddress1()));

      customerElement.appendChild(MVCHelper.buildDBElement(xmlDoc, 
              "CUSTOMERADDRESS2", customer.getCustomerAddress2()));

      customerElement.appendChild(MVCHelper.buildDBElement(xmlDoc, 
              "CUSTOMERCITY", customer.getCustomerCity()));

      /* Retrieving my postal code information */
      PostalCodesHome postalCodesHome = 
        (PostalCodesHome) _ctx.lookup("PostalCodes");
      PostalCodes postalCodes = 
        postalCodesHome.findByPrimaryKey(customer.getCustomerPostalCode());

      customerElement.appendChild(MVCHelper.buildDBElement(xmlDoc, 
              "CUSTOMERSTATE", postalCodes.getStateProv()));
      customerElement.appendChild(MVCHelper.buildDBElement(xmlDoc, 
              "CUSTOMERZIP", postalCodes.getPostalCode()));

      rootElement.appendChild(customerElement);
      customerElement = xmlDoc.createElement("CUSTOMER");

      MVCHelper.printDOM(xmlDoc, new File("c:\\temp\\output.xml"));
    } 

    return xmlDoc;
  } 

  /*
   * Standard EJB Methods.  For simplicity's sake these methods have
   * been implemented as empty methods.
   */
  public void ejbCreate() {}
  public void ejbRemove() {}
  public void ejbActivate() {}
  public void ejbPassivate() {}
  public void setSessionContext(SessionContext sessionCtx) {}
}