Java与Flex学习笔记（5）----Flex与Java通信之HttpService方式_JAVA_编程开发_程序员俱乐部

? ? Flex用RemoteObject方式与Java通信是最常用的方式，这是一种最直观的方式。当然Flex也可以用HttpService与服务器类如servlet通信，这也是本次学习的重点。

? ? ? ? ?这次学习是在上节的基础上进行的。本节学习用到的LoginEvent.as,LoginModule.mxml文件代码如上节所示。

好了，新建一个servlet类LoginServlet.java，代码如下所示：

[java]?view plaincopyprint?

1. package?com.yqsn.servlet;??
2. ???
3. ???
4. import?java.io.IOException;??
5. import?java.io.PrintWriter;??
6. ???
7. import?javax.servlet.ServletException;??
8. import?javax.servlet.http.HttpServlet;??
9. import?javax.servlet.http.HttpServletRequest;??
10. import?javax.servlet.http.HttpServletResponse;??
11. ???
12. public?class?LoginServlet?extends?HttpServlet?{??
13. ????@Override??
14. ????protected?void?service(HttpServletRequest?req,?HttpServletResponse?resp)??
15. ???????????throws?ServletException,?IOException?{??
16. ???????//?TODO?Auto-generatedmethod?stub??
17. ???????req.setCharacterEncoding("utf-8");??
18. ???????resp.setCharacterEncoding("utf-8");??
19. ???????PrintWriter?out=resp.getWriter();??
20. ???????String?username=req.getParameter("username");??
21. ???????String?passworld=req.getParameter("passworld");??
22. ???????//System.out.println(username+":"+passworld);??
23. ???????if(username.equals("admin")&&?passworld.equals("123")){??
24. ???????????out.print(true);??
25. ???????}else{??
26. ???????????out.print(false);??
27. ???????}??
28. ????}??
29. }??

?

?

?

? ? ? ? 这个servlet在web.xml中的配置如下所示：

?

[html]?view plaincopyprint?

1. <servlet>??
2. ????<servlet-name>LoginServlet</servlet-name>??
3. ????<servlet-class>com.yqsn.servlet.LoginServlet</servlet-class>??
4. ????</servlet>??
5. <servlet-mapping>??
6. ????<servlet-name>LoginServlet</servlet-name>??
7. ????<url-pattern>/LoginServlet</url-pattern>??
8. ??</servlet-mapping>??

?

? ? ? ?将MyEclipse切换到flash视图，新建一个application文件HttpServiceDemo.mxml，代码如下所示：

?

[html]?view plaincopyprint?

1. <?xmlversionxmlversion="1.0"?encoding="utf-8"?>??
2. <s:Application?xmlns:fx="http://ns.adobe.com/mxml/2009"??
3. ??????????????xmlns:s="library://ns.adobe.com/flex/spark"??
4. ??????????????xmlns:mx="library://ns.adobe.com/flex/mx"?minWidth="955"?minHeight="600">??
5. ?????
6. ????<fx:Script>??
7. ???????<![CDATA[?
8. ???????????import?com.flex.ases.LoginEvent;?
9. ???????????import?com.flex.ases.LoginMess;?
10. ???????????import?com.flex.module.LoginModule;?
11. ???????????
12. ???????????import?mx.controls.Alert;?
13. ???????????import?mx.managers.PopUpManager;?
14. ???????????import?mx.rpc.events.FaultEvent;?
15. ???????????import?mx.rpc.events.ResultEvent;?
16. ???????????private?var?loginModule:LoginModule=new?LoginModule();?
17. ???????????[Bindable]?
18. ???????????private?var?username:String;?
19. ???????????[Bindable]?
20. ???????????private?varpassworld:String;?
21. ???????????protected?function?login_clickHandler(event:MouseEvent):void?
22. ???????????{?
23. ??????????????//?TODOAuto-generated?method?stub?
24. ???????????????PopUpManager.addPopUp(loginModule,this,true);?
25. ???????????????PopUpManager.centerPopUp(this.loginModule);?
26. ???????????????loginModule.addEventListener(LoginEvent.LOGIN_EVENT,loginHander);?
27. ???????????}?
28. ???????????public?function?loginHander(event:LoginEvent):void{?
29. ??????????????//varobj:Object=event.loginMess?as?Object;?
30. ??????????????username=event.loginMess['username'];?
31. ??????????????passworld=event.loginMess['passworld'];?
32. ??????????????httpServiceSend.send();?
33. ???????????}?
34. ???????????
35. ???????????protected?function?httpServiceSend_faultHandler(event:FaultEvent):void?
36. ???????????{?
37. ??????????????//?TODOAuto-generated?method?stub?
38. ??????????????Alert.show(event.fault.message?as?String,"提示");?
39. ??????????????
40. ???????????}?
41. ???????????
42. ???????????protected?function?httpServiceSend_resultHandler(event:ResultEvent):void?
43. ???????????{?
44. ??????????????//?TODOAuto-generated?method?stub?
45. ??????????????var?result:Boolean=event.result?as?Boolean;?
46. ??????????????if(result==true){?
47. ??????????????????Alert.show(username+",欢迎您回来！","提示");?
48. ??????????????????aaa.text=username+",欢迎您回来！";?
49. ??????????????????login.label="";?
50. ??????????????????bbb.text="";?
51. ??????????????????
52. ??????????????}else{?
53. ??????????????????Alert.show("对不起，用户名或密码不存在！","提示");?
54. ??????????????}?
55. ??????????????//Alert.show("成功了！");?
56. ???????????}?
57. ???????????
58. ???????]]>??
59. ????</fx:Script>??
60. ?????
61. ????<fx:Declarations>??
62. ???????<!--?Place?non-visualelements?(e.g.,?services,?value?objects)?here?-->??
63. ???????<s:HTTPService?id="httpServiceSend"??url="http://localhost:8000/JavaAndFlexDemo/LoginServlet"?useProxy="false"fault="httpServiceSend_faultHandler(event)"result="httpServiceSend_resultHandler(event)"?>??
64. ???????????<s:request?>??
65. ??????????????<username>{username}</username>??
66. ???????????????<passworld>{passworld}</passworld>??
67. ???????????</s:request>??
68. ???????</s:HTTPService>??
69. ????</fx:Declarations>??
70. ????<s:Label?x="200"?y="150"?width="182"?height="27"?fontSize="18"?id="aaa"?text="您还没有登陆，现在就"?verticalAlign="middle"/>??
71. ????<mx:LinkButton?x="393"??y="150"?width="57"??height="27"?label="登陆"?id="login"?fontSize="18"click="login_clickHandler(event)"/>??
72. ????<s:Label?x="459"?y="150"?width="37"?height="27"?id="bbb"?fontSize="18"?text="吧！"?verticalAlign="middle"/>??
73. </s:Application>??

?

?

? ? ? ? ?从代码中我们可以看出，我们先定义一个HttpServlet发送请求httpServiceSend，然后通过下面这种方式存值：

?

[html]?view plaincopyprint?

1. <s:request?>??
2. ??????????????<username>{username}</username>??
3. ??????????????<passworld>{passworld}</passworld>??
4. ???????????</s:request>??

?

? ? ? ? ?这种方式很简单，我们在后台通过request. getParameter(“参数名”)取值就可以了，当然我们也可以在loginHander(event:LoginEvent)函数中通过下面方式存值并发送请求：

[html]?view plaincopyprint?

1. public?functionloginHander(event:LoginEvent):void{??
2. ??????????????//varobj:Object=event.loginMess?as?Object;??
3. ??????????????username=event.loginMess['username'];??
4. ??????????????passworld=event.loginMess['passworld'];??
5. ??????????????var?obj:Object=new?Object;??
6. ??????????????obj.username=username;??
7. ??????????????obj.passworld=passworld;??
8. ??????????????httpServiceSend.send(obj);??
9. ???????????}??

?

?

? ? 运行结果是一样的，你可以试试。

? ? 好了，程序算是完成了，现在开始验收结果。

?

打开服务器并部署项目，运行felx页面RemoteObjectDemo.mxml，如下所示：

?

? ? ? ? 当我们点击“登陆”按钮后，弹出module页面，如下所示：

?

? ? ? 当我们输入的用户名和密码都正确时则提示你登陆正确：

?

? ? ? ?输入错误则提示你输入不正确：

?

? ? ? 可以看出，我们输入的用户名与密码已经用httpservice方式发送到后台并且成功接受了并将结果返回给前台了。

? ? ? ?好了，就学习这么多，下节将学习WebService方式。