DWR AND SPRING 結合
dwr與spring相結合 AJAX，或者說是異步JavaScript和XML，
描述了一種使用混合了HTML(或XHTML)和層疊樣式表作爲表達信息,
來創建交互式的Web應用的開發技術;文檔對象模型（DOM），
JavaScript,動態地顯示和與表達信息進行交互;並且XMLHttpRequest對象與Web服務器異步地交換和處理數據。
DWR(直接Web遠程控制)項目是在Apache許可下的一個開源的解決方案，
它供給那些想要以一種簡單的方式使用AJAX和 XMLHttpRequest的開發者。
它具有一套Javascript功能集，它們把從HTML頁面調用應用服務器上的Java對象的方法簡化了。
它操控不同類型的參數，並同時保持了HTML代碼的可讀性，它可以與spring結合在一起。
舉個非常實用的小例子，檢測是否有重複的用戶名
1。web。xml的配置（包括spring和dwr）
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<?xml version="1.0" encoding="ISO-8859-1"?>
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<!DOCTYPE web-app
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PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
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"http://java.sun.com/j2ee/dtds/web-app_2_3.dtd">
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<web-app>
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<context-param>
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<param-name>log4jConfigLocation</param-name>
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<param-value>/WEB-INF/log4j.properties</param-value>
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</context-param>
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<context-param>
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<param-name>contextConfigLocation</param-name>
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<param-value>/WEB-INF/applicationContext.xml,/WEB-INF/main-servlet.xml</param-value>
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</context-param>
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<listener>
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<listener-class>org.springframework.web.util.Log4jConfigListener</listener-class>
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</listener>
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<servlet>
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<servlet-name>context</servlet-name>
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<servlet-class>org.springframework.web.context.ContextLoaderServlet</servlet-class>
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<load-on-startup>1</load-on-startup>
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</servlet>
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<servlet>
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<servlet-name>dwr</servlet-name>
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<display-name>DWR Servlet</display-name>
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<description>Direct Web Remoter Servlet</description>
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<servlet-class>uk.ltd.getahead.dwr.DWRServlet</servlet-class>
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<init-param>
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<param-name>debug</param-name>
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<param-value>true</param-value>
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</init-param>
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</servlet>
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<servlet-mapping>
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<servlet-name>dwr</servlet-name>
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<url-pattern>/dwr/*</url-pattern>
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</servlet-mapping>
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</web-app>
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<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd">
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<beans>
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<bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
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<property name="location">
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<value>/WEB-INF/jdbc.properties</value>
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</property>
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</bean>
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<!-- Local DataSource that works in any environment -->
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<bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource">
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<property name="driverClassName">
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<value>${jdbc.driverClassName}</value>
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</property>
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<property name="url">
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<value>${jdbc.url}</value>
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</property>
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<property name="username">
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<value>${jdbc.username}</value>
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</property>
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<property name="password">
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<value>${jdbc.password}</value>
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</property>
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</bean>
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<!--OrderManager-->
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<bean id="UserManager" class="dwr.manager.UserManager">
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<property name="dataSource">
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<ref local="dataSource"/>
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</property>
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</bean>
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</beans>
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package dwr.manager;
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import org.springframework.jdbc.core.support.JdbcDaoSupport;
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import org.apache.commons.logging.Log;
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import org.apache.commons.logging.LogFactory;
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public class UserManager extends JdbcDaoSupport {
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private final Log log = LogFactory.getLog(getClass().getName());
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public boolean getUser(String username)
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{
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String sql="select count(*) from user where userName=? ";
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int i=getJdbcTemplate().queryForInt(sql,new Object[]{username});
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if(i>0)
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return true;
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else
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return false;
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}
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}
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<%@ page contentType="text/html;charset=GBK" language="java" %>
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<html>
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<head><title>Simple jsp page</title></head>
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<script type='text/javascript' src='<%=request.getContextPath()%>/dwr/interface/UserManager.js'>
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</script>
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<script type='text/javascript' src='<%=request.getContextPath()%>/dwr/engine.js'>
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</script>
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<script type='text/javascript'
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src='<%=request.getContextPath()%>/dwr/util.js'></script>
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<script type="text/javascript">
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function showResult(b) {
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if (b) {
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alert("已經有重複的登錄名了！");
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} else {
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alert("登錄名尚未註冊過！");
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}
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}function checkRepeat(s) {
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var o = getElement(s);
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if (o) {
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UserManager.getUser(o.value, showResult);
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}
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}
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function getElement(name) {
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var result = null;
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var objs = document.getElementsByName(name);
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if (objs) {
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var o = objs[0];
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result = o;
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}
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return result;
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}
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</script>
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<body>
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<input type="text" name="user" >
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<input type="button" οnclick="checkRepeat('user')" value="檢查是否重複">
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</body>
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</html>
描述了一種使用混合了HTML(或XHTML)和層疊樣式表作爲表達信息,
來創建交互式的Web應用的開發技術;文檔對象模型（DOM），
JavaScript,動態地顯示和與表達信息進行交互;並且XMLHttpRequest對象與Web服務器異步地交換和處理數據。
DWR(直接Web遠程控制)項目是在Apache許可下的一個開源的解決方案，
它供給那些想要以一種簡單的方式使用AJAX和 XMLHttpRequest的開發者。
它具有一套Javascript功能集，它們把從HTML頁面調用應用服務器上的Java對象的方法簡化了。
它操控不同類型的參數，並同時保持了HTML代碼的可讀性，它可以與spring結合在一起。
舉個非常實用的小例子，檢測是否有重複的用戶名
1。web。xml的配置（包括spring和dwr）
<?xml version="1.0" encoding="ISO-8859-1"?><!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/j2ee/dtds/web-app_2_3.dtd"> <web-app> <context-param> <param-name>log4jConfigLocation</param-name> <param-value>/WEB-INF/log4j.properties</param-value> </context-param> <context-param> <param-name>contextConfigLocation</param-name> <param-value>/WEB-INF/applicationContext.xml,/WEB-INF/main-servlet.xml</param-value> </context-param> <listener> <listener-class>org.springframework.web.util.Log4jConfigListener</listener-class> </listener> <servlet> <servlet-name>context</servlet-name> <servlet-class>org.springframework.web.context.ContextLoaderServlet</servlet-class> <load-on-startup>1</load-on-startup> </servlet> <servlet> <servlet-name>dwr</servlet-name> <display-name>DWR Servlet</display-name> <description>Direct Web Remoter Servlet</description> <servlet-class>uk.ltd.getahead.dwr.DWRServlet</servlet-class> <init-param> <param-name>debug</param-name> <param-value>true</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>dwr</servlet-name> <url-pattern>/dwr/*</url-pattern> </servlet-mapping></web-app>2。dwr。xml的配置
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 1.0//EN" "http://www.getahead.ltd.uk/dwr/dwr10.dtd">
<dwr>
<allow>
<create
creator="spring"
javascript="UserManager">
<param name="beanName" value="UserManager"/>
</create>
</allow>
</dwr>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 1.0//EN" "http://www.getahead.ltd.uk/dwr/dwr10.dtd">
<dwr>
<allow>
<create
creator="spring"
javascript="UserManager">
<param name="beanName" value="UserManager"/>
</create>
</allow>
</dwr>
3。applicationContext.xml文件
<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN" "http://www.springframework.org/dtd/spring-beans.dtd"><beans><bean id="propertyConfigurer" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"> <property name="location"> <value>/WEB-INF/jdbc.properties</value> </property> </bean> <!-- Local DataSource that works in any environment --> <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> <property name="driverClassName"> <value>${jdbc.driverClassName}</value> </property> <property name="url"> <value>${jdbc.url}</value> </property> <property name="username"> <value>${jdbc.username}</value> </property> <property name="password"> <value>${jdbc.password}</value> </property> </bean> <!--OrderManager--> <bean id="UserManager" class="dwr.manager.UserManager"> <property name="dataSource"> <ref local="dataSource"/> </property> </bean> </beans>
4。。spring的bean
package dwr.manager;import org.springframework.jdbc.core.support.JdbcDaoSupport;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory; 
public class UserManager extends JdbcDaoSupport {
private final Log log = LogFactory.getLog(getClass().getName());public boolean getUser(String username)
{
String sql="select count(*) from user where userName=? "; int i=getJdbcTemplate().queryForInt(sql,new Object[]{username}); if(i>0) return true; else return false;
}
}
5。jsp的代碼
<%@ page contentType="text/html;charset=GBK" language="java" %><html><head><title>Simple jsp page</title></head><script type='text/javascript' src='<%=request.getContextPath()%>/dwr/interface/UserManager.js'></script><script type='text/javascript' src='<%=request.getContextPath()%>/dwr/engine.js'></script><script type='text/javascript' src='<%=request.getContextPath()%>/dwr/util.js'></script> <script type="text/javascript"> function showResult(b) { if (b) { alert("已經有重複的登錄名了！"); } else { alert("登錄名尚未註冊過！"); } }function checkRepeat(s) { var o = getElement(s); if (o) { UserManager.getUser(o.value, showResult); } } function getElement(name) { var result = null; var objs = document.getElementsByName(name); if (objs) { var o = objs[0]; result = o; } return result; } </script><body><input type="text" name="user" ><input type="button" οnclick="checkRepeat('user')" value="檢查是否重複"></body></html>
