JAVA

				????<servlet>
????????<servlet-name>dwr-invoker</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-invoker</servlet-name>
????????<url-pattern>/dwr/*</url-pattern>
????</servlet-mapping>
		

一個可選的步驟是設置DWR為調(diào)試模式—象上面的例子那樣—在servlet描述段中將debug參數(shù)設為true。當DWR在調(diào)試模式時，你可以從HTMl網(wǎng)頁中看到所有的可訪問的Java對象。包含了可用對象列表的網(wǎng)頁會出現(xiàn)在/WEBAPP/dwr這個url上，它顯示了對象的公共方法。所列方法可以從頁面中調(diào)用，允許你，第一次，運行服務器上的對象的方法。下圖顯示了調(diào)試頁的樣子:


調(diào)試頁

現(xiàn)在你必須讓DWR知道通過XMLHttpRequest對象，什么對象將會接收請求。這個任務由叫做dwr.xml的配置文件來完成。在配置文件中，定義了DWR允許你從網(wǎng)頁中調(diào)用的對象。從設計上講，DWR允許訪問所有公布類的公共方法，但在我們的例子中，我們只允許訪問幾個方法。下面是我們示例的配置文件:

				<dwr>
????<allow>
????????<convert converter="bean" match="dwr.sample.Apartment"/>
????????<create creator="new" javascript="ApartmentDAO" class="dwr.sample.ApartmentDAO">
????????????<include method="findApartments"/>
????????????<include method="countApartments"/>
????????</create>
????</allow>
</dwr>
		

				??<script src='dwr/interface/ApartmentDAO.js'></script>
??<script src='dwr/engine.js'></script>
??<script src='dwr/util.js'></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 loadTotal(data) {
????document.getElementById("totalRecords").innerHTML = data;
}
		

				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 = '';
}

function fillTable(apartment) {
????DWRUtil.addRows("apartmentsbody", apartment, [ getId, getAddress, getBedrooms, getBathrooms, getPrice ]);
}