Kevin的技術(shù)家園

進(jìn)行JSP開發(fā)時(shí)，利用可中MVC框架使得開發(fā)起來非常便利。比較有名的MVC框架有struts,spring等。簡單，快捷的Struts是應(yīng)用最廣泛的一個。
arcIMS的客戶端開發(fā)模式分HTML Viewer和Java Viewer兩種，Java Viewer由于需要在客戶端安裝JRE，在webGIS開發(fā)中已經(jīng)被一棒打死。而arcIMS提供的HTML Viewer中，大量處理地圖的代碼都是用JavaScript編寫，界面代碼和業(yè)務(wù)處理代碼大量的混雜在一起，調(diào)試起來很不方便。利用struts對arcIMS請求代碼進(jìn)行封裝，實(shí)現(xiàn)了業(yè)務(wù)代碼和界面代碼的分離。
（1）在struts中新建一個action
<action-mappings >
??? <action
????? attribute="requestMapForm"
????? input="/index1.jsp"
????? name="requestMapForm"
????? path="/requestMap"
????? scope="request"
????? type="com.suzhou.struts.action.RequestMapAction" />
? </action-mappings>
（2）在map.jsp中新建一個form，對應(yīng)這個action，記住，struts的<url-pattern>必須設(shè)置成*.do的格式（在web.xml中設(shè)置），如果設(shè)置成/do/*格式，多次請求這個action會出現(xiàn)找不到action的錯誤。
<FORM action="requestMap.do" name="requestMapForm">
<INPUT type="submit" value="確定"/>
</FORM>
（3）編寫action代碼

代碼
??1 package ?com.suzhou.struts.action;
??2
??3 import ?javax.servlet.http.HttpServletRequest;
??4 import ?javax.servlet.http.HttpServletResponse;
??5
??6 import ?org.apache.struts.action.Action;
??7 import ?org.apache.struts.action.ActionForm;
??8 import ?org.apache.struts.action.ActionForward;
??9 import ?org.apache.struts.action.ActionMapping;
?10
?11 import ?com.esri.aims.mtier.io.ConnectionProxy;
?12 import ?com.esri.aims.mtier.model.map.Map;
?13 import ?com.suzhou.struts.form.RequestMapForm;
?14
?15 /**?*/ /** ?
?16 ?*?MyEclipse?Struts
?17 ?*?Creation?date:?03-29-2006
?18 ?*?
?19 ?*?XDoclet?definition:
?20 ?*?@struts.action?path="/requestMap"?name="requestMapForm"?input="jspForm.jsp"?scope="request"?validate="true"
?21 ? */
?22 public ? class ?RequestMapAction? extends ?Action? {
?23
?24 ???? // ?---------------------------------------------------------?Instance?Variables
?25
?26 ???? // ?---------------------------------------------------------?Methods
?27
?28 ???? /**?*/ /** ?
?29 ?????*?Method?execute
?30 ?????*? @param ?mapping
?31 ?????*? @param ?form
?32 ?????*? @param ?request
?33 ?????*? @param ?response
?34 ?????*? @return ?ActionForward
?35 ????? */
?36 ???? public ?ActionForward?execute(
?37 ????????ActionMapping?mapping,
?38 ????????ActionForm?form,
?39 ????????HttpServletRequest?request,
?40 ????????HttpServletResponse?response)? {
?41 ????????RequestMapForm?requestMapForm? = ?(RequestMapForm)?form;
?42 ????????String?strAction = requestMapForm.getAction();
?43 ????????
?44 ????????ConnectionProxy?conn? = ? new ?ConnectionProxy();
?45 ????????conn.setHost( " menglikun " ); // ArcIMS服務(wù)器的名稱或者IP
?46 ????????conn.setConnectionType(conn.TCP);
?47 ????????conn.setPort( 5300 ); // ArcIMS服務(wù)器的端口
?48 ????????conn.setService( " zixian " ); // 需要調(diào)用的ArcIMS服務(wù)器的服務(wù)名稱
?49 ????????conn.setDisplayMessages( false );
?50 ????????
?51 ???????? // 使用Map對象的訪問方式
?52 ???????? /**/ /*
?53 ????????Map?map=(Map)request.getSession().getAttribute("gongzhongMap");
?54 ????????if(map==null){
?55 ????????????//如果Map對象為空，新建一個Map對象
?56 ????????????map=new?Map();
?57 ????????????try{
?58 ????????????????map.initMap(conn,0,false,false,false,false);
?59 ????????????????map.refresh();
?60 ????????????????request.setAttribute("mapURL",map.getMapOutput().getURL());
?61 ????????????????request.getSession().setAttribute("gongzhongMap",map);
?62 ????????????????return?mapping.getInputForward();
?63 ????????????}catch(Exception?ex){
?64 ????????????????System.out.println(ex.getMessage());
?65 ????????????????ex.printStackTrace();
?66 ????????????}
?67 ????????}else{
?68 ????????????map.refresh();
?69 ????????????request.setAttribute("mapURL",map.getMapOutput().getURL());
?70 ????????????request.getSession().setAttribute("gongzhongMap",map);
?71 ????????????return?mapping.getInputForward();
?72 ????????}
?73 ???????? */
?74 ???????? /**/ /*
?75 ?????????*?不使用Map對象，直接通過arcXML進(jìn)行請求的訪問方式。
?76 ?????????*?這種方式的好處是可以使用arcXML所有的功能，功能非常強(qiáng)大。
?77 ?????????*?但要自己寫代碼處理arcIMS返回的結(jié)果。
?78 ????????? */
?79 ????????String?strArcXML = " <?xml?version=\ " 1.0 \ " ?encoding=\ " UTF - 8 \ " ??> "
?80 ???????????? + " <ARCXML?version=\ " 1.1 \ " > "
?81 ???????????? + " <REQUEST> "
?82 ???????????? + " <GET_IMAGE> "
?83 ???????????? + " <PROPERTIES> "
?84 ???????????? + " <ENVELOPE?minx=\ " - 13.62 \ " ?miny=\ " 33.91 \ " ?maxx=\ " 53.62 \ " ?maxy=\ " 73.33 \ " ?/> "
?85 ???????????? + " <IMAGESIZE?width=\ " 600 \ " ?height=\ " 400 \ " /> "
?86 ???????????? + " </PROPERTIES> "
?87 ???????????? + " <LAYER?type=\ " acetate\ " ?name=\ " acetate\ " ?id=\ " acetate\ " > "
?88 ???????????? + " <OBJECT?units=\ " pixel\ " > "
?89 ???????????? + " <NORTHARROW?type=\ " 4 \ " ?coords=\ " 20 ? 30 \ " ?shadow=\ " 32 , 32 , 32 \ " ?size=\ " 15 \ " ?/> "
?90 ???????????? + " </OBJECT> "
?91 ???????????? + " </LAYER> "
?92 ???????????? + " </GET_IMAGE> "
?93 ???????????? + " </REQUEST> "
?94 ???????????? + " </ARCXML> " ;
?95 ???????? try {
?96 ????????????conn.send(strArcXML);
?97 ???????????? return ?mapping.getInputForward();
?98 ????????} catch (Exception?ex) {
?99 ????????????System.out.println(ex.getMessage());
100 ????????????ex.printStackTrace();
101 ????????}
102 ???????? return ? null ;
103 ????}
104 }