PROCEDURE   A(errbuf           OUT VARCHAR2,
                            retcode                   OUT    VARCHAR2,
                            p_1                        IN    VARCHAR2,
                            p_2                        IN    NUMBER);

           end XXXX_X_XXX_PKG ;

 æ³¨ï¼šåŒ…头中声明一个Procedure, 包体中声明一个主Procedure(例如: A),多个从Procedure(一般是些共用方æ³?(例如åQšB), 注意包体中Procedure实现‹Æ¡åºåQŒåº”先声明B ,
在A˜q‡ç¨‹é‡Œï¼Œå¯ä»¥è°ƒç”¨B.

æ–ÒŽ(gu¨©)³•äº? 
      包头: 
      create or replace package   XXXX_X_XXX_PKG    is

                   PROCEDURE    A(errbuf           OUT VARCHAR2,
                            retcode                   OUT    VARCHAR2,
                            p_1                        IN    VARCHAR2,
                            p_2                        IN    NUMBER);

                   PROCEDURE    B( retcode          OUT    VARCHAR2,
                            p_1                        IN    VARCHAR2,);

           end XXXX_X_XXX_PKG ;
      包体ä¸?此时A可以直接引用B,不论实现‹Æ¡åº.

 <welcome-file-list>
    <welcome-file>search.jsp</welcome-file>
 </welcome-file-list>

2.dwr.xml
 <dwr>
    <allow><convert convert="bean"  match="dwr.sample.Apartment"/>
    <create>
           <creator="new" javascript="ApartmentDAO" class="dwr.sample.ApartmentDAO">
                  <include method="findApartments"/>
                  <include method="countApartments"/>
           </creator>
    </create>
    </allow>
</dwr>
3.DB
CREATE TABLE APARTMENTS (id INTEGER, bedrooms INTEGER, bathrooms INTEGER, price INTEGER, address VARCHAR, city VARCHAR, province VARCHAR);
INSERT INTO APARTMENTS VALUES (16001, 1, 1, 850, '123 King St. East', 'Toronto', 'ON');
INSERT INTO APARTMENTS VALUES (16002, 2, 1, 1000, '1023 Yonge Ave.', 'Toronto', 'ON');
INSERT INTO APARTMENTS VALUES (16003, 2, 2, 1050, '27 Winchester St.', 'Toronto', 'ON');
4.Apertment.java
普通的javabean
5.DBUtils.java
   数据库链接类
   public class DBUtils {

 /*
  * Creates the sample data (table and records).
  */
 public static void setupDatabase(BufferedReader reader) {
  Connection c = null;
  Statement stmt = null;
  try {
   c = openConnection();
   stmt = c.createStatement();
   // reads the file with the SQL statements
   String line;
   while ((line = reader.readLine()) != null) {
    stmt.execute(line);
   }
   stmt.close();
   c.close();
  } catch (IOException e) {
   e.printStackTrace();
  } catch (SQLException e) {
   e.printStackTrace();
  } finally {
   try {
    stmt.close();
    c.close();
   } catch (SQLException e) {
    e.printStackTrace();
   }
  }
 }
 
 /*
  * Opens a database connection.
  */
 public static Connection openConnection() throws SQLException {
  Connection c = DriverManager.getConnection("jdbc:hsqldb:mem:dwr-sample", "sa", "");
  return c;
 }
 
}

6.ContextListener.java
   实现了ServletContextListerer接口的类
   public class ContextListener implements javax.servlet.ServletContextListener {

 /**
  * This method is invoked when the Web Application has been removed and is
  * no longer able to accept requests.
  * @param event
  */
 public void contextDestroyed(ServletContextEvent event) {
 }

 /**
  * This method is invoked when the Web Application is ready to service requests.
  * @param event
  */
 public void contextInitialized(ServletContextEvent event) {
  try {
   // load the driver
   Class.forName("org.hsqldb.jdbcDriver");
   // create the table and add sample data
   InputStreamReader in = new InputStreamReader(getClass().getClassLoader().getResourceAsStream("db.sql"));
   BufferedReader reader = new BufferedReader(in);
   DBUtils.setupDatabase(reader);
  } catch (ClassNotFoundException e) {
   e.printStackTrace();
  }
  
 }

}
7.ApartmentDAO.java
   业务逻辑�br />   public class ApartmentDAO {
 
 /**
  * Returns the available apartments based on the search criteria.
  * @param bedrooms minimum number of bedrooms
  * @param bathrooms minimum number of bathrooms
  * @param price maximum price to be paid
  * @return
  */
 public Collection findApartments(int bedrooms, int bathrooms, int price) {
  Collection list = new Vector();
  String sql = "select * from APARTMENTS" +
    createSearchWhereClause(bedrooms, bathrooms, price) +
    "order by bedrooms, bathrooms, price";

  // define db variables
  Connection c = null;
  Statement stmt = null;
  try {
   c = DBUtils.openConnection();
   stmt = c.createStatement();
   // just run the sql statement
   ResultSet rs = stmt.executeQuery(sql);
   while(rs.next()) {
    Apartment apartment = this.getApartment(rs);
    list.add(apartment);
   }
  } catch (SQLException e) {
   e.printStackTrace();
  } finally {
   try {
    stmt.close();
    c.close();
   } catch (SQLException e) {
    e.printStackTrace();
   }
  }

  return list;
 }
 
 /**
  * Returns the number of available apartments based on the search criteria.
  * @param bedrooms minimum number of bedrooms
  * @param bathrooms minimum number of bathrooms
  * @param price maximum price to be paid
  * @return
  */
 public int countApartments(int bedrooms, int bathrooms, int price) {
  String sql = "select count(*) as total from APARTMENTS" + createSearchWhereClause(bedrooms, bathrooms, price);
  int numberApartments = -1;
  // define db variables
  Connection c = null;
  Statement stmt = null;
  try {
   c = DBUtils.openConnection();
   stmt = c.createStatement();
   // just run the sql statement
   ResultSet rs = stmt.executeQuery(sql);
   if (rs.next()) {
    numberApartments = rs.getInt("total");
   }
  } catch (SQLException e) {
   e.printStackTrace();
  } finally {
   try {
    stmt.close();
    c.close();
   } catch (SQLException e) {
    e.printStackTrace();
   }
  }
  
  return numberApartments;
 }
 
 /**
  * Creates a Unit object from the database.
  * @param rs
  * @return
  * @throws SQLException
  */
 private Apartment getApartment(ResultSet rs) throws SQLException {
  Apartment ap = new Apartment();
  ap.setId(rs.getInt("id"));
  ap.setAddress(rs.getString("address"));
  ap.setBedrooms(rs.getInt("bedrooms"));
  ap.setBathrooms(rs.getInt("bathrooms"));
  ap.setPrice(rs.getInt("price"));
  ap.setCity(rs.getString("city"));
  ap.setProvince(rs.getString("province"));
  return ap;
 }
 
 
 /**
  * Creates the where clause for the search SQL statement.
  * @param bedrooms
  * @param bathrooms
  * @param price
  * @return
  */
 private String createSearchWhereClause(int bedrooms, int bathrooms, int price) {
  String where = " where bedrooms >= " + bedrooms +
    " and bathrooms >= " + bathrooms +
    " and price < " + price;
  return where;
 }

}
8. search.jsp
  <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
  <title>DWR Example</title>

   <style type="text/css" media="screen">
       @import url( style.css );
   </style> 
 
  <script src='dwr/interface/ApartmentDAO.js'></script>
  <script src='dwr/engine.js'></script>
  <script src='dwr/util.js'></script>
  <script>
 
  function updateTotal() {
    $("resultTable").style.display = 'none';
    var bedrooms = document.getElementById("bedrooms").value;
    var bathrooms = document.getElementById("bathrooms").value;
    var price = document.getElementById("price").value;
    ApartmentDAO.countApartments(loadTotal, bedrooms, bathrooms, price);
  }

  function updateResults() {
    DWRUtil.removeAllRows("apartmentsbody");
    var bedrooms = document.getElementById("bedrooms").value;
    var bathrooms = document.getElementById("bathrooms").value;
    var price = document.getElementById("price").value;
    ApartmentDAO.findApartments(fillTable, bedrooms, bathrooms, price);
    $("resultTable").style.display = '';
  }
 
  var getId = function(unit) { return unit.id };
  var getAddress = function(unit) { return unit.address };
  var getBedrooms = function(unit) { return unit.bedrooms };
  var getBathrooms = function(unit) { return unit.bathrooms };
  var getPrice = function(unit) { return unit.price };
   
  function loadTotal(data) {
    document.getElementById("totalRecords").innerHTML = data;
  }
 
  function fillTable(apartment) {
    DWRUtil.addRows("apartmentsbody", apartment, [ getId, getAddress, getBedrooms, getBathrooms, getPrice ]);
  }
 
</script>

</head>

<body onload="updateTotal();">

<h2>Find an apartment to rent</h2>

<table border="0">
<form name="rentalForm">
  <tr width="400">
   <td width="100">City</td>
   <td width="300">Toronto</td>
  </tr>
  <tr>
   <td>Beds</td>
   <td>
    <select id="bedrooms" onchange="updateTotal()">
     <option value="1">1 or more</option>
     <option value="2">2 or more</option>
     <option value="3">3 or more</option>
     <option value="4">4 or more</option>
    </select>
   </td>
  </tr>

  <tr>
   <td>Baths</td>
   <td>
    <select id="bathrooms" onchange="updateTotal()">
     <option value="1">1 or more</option>
     <option value="2">2 or more</option>
     <option value="3">3 or more</option>
     <option value="4">4 or more</option>
    </select>
   </td>
  </tr>

  <tr>
   <td>Price</td>
   <td>
    <select id="price" onchange="updateTotal()">
     <option value="800">under $800</option>
     <option value="1000">under $1,000</option>
     <option value="1250">under $1,250</option>
     <option value="1500" selected="selected">under $1,500</option>
     <option value="1800">under $1,800</option>
     <option value="2000">under $2,000</option>
    </select>
   </td>
  </tr>

  <tr>
   <td colspan="2">
    <blockquote>
     Available apartments: <span id="totalRecords" style="font-weight:bold;"></span>
    </blockquote>
   </td>
  </tr>

</form>
</table>

<p><input type="button" value="Show results!" onClick="updateResults();"></p>

<div id="resultTable">

<h2>Results</h2>

 <table border="1">
  <thead>
    <tr>
      <th width="40">Id</th>
      <th width="180">Address</th>
      <th width="60">Beds</th>
      <th width="60">Baths</th>
      <th width="60">Price</th>
    </tr>
  </thead>
  <tbody id="apartmentsbody">

  </tbody>
 </table>
</div>

</body>
</html>

ç”׃ºŽ™å¹ç›®éœ€è¦?需在我们现有的struts、hibernate工程上集成ajax功能.™å¹ç›®¾l„决定ä‹É用Dwr.
刚开始研½I¶Dwr.觉得真的很不é”? 只需很少量的代码,ž®Þpƒ½åœ¨çŽ°æœ‰çš„工程上集成ajax技æœ? 期待Dwr有更辉煌的明天！
喜欢Dwr技术的IT界朋友可以与本äh联系åQæœ›æå‡ºå¥½çš„意见与徏è®?