上篇文章介绍了通过使用dwr在EXTJS代码里直接调用后台的Java方法.这篇文章介绍在没有调用Java方法,没有返回值的情况下获取Java的返回信息.就要用到的Extjs的submit配置项---success和failure来进行配置.
Ext.form.Action.Submit的配置选项success、failure是根据返回json中success属性判断的&＃xff0c;如果success为true&＃xff0c;则success&＃xff0c;false则failure&＃xff0c;如果无json中无success属性&＃xff0c;failure&＃xff0c;故要提示操作是否成功&＃xff0c;必须要返回success属性。
这种方法用的也很多,在js界面除了调用Java方法来完成各种验证和取值外,还会执行表单的提交.提交了表单,并没有调用后台方法,通过这种方法便可以知道执行结果,来显示执行信息.
EXTJS页面部分代码:
-
- var submitButton &＃61; new Ext.Button(
- {
- text: &＃39;提交&＃39;,
- iconCls: &＃39;c_page_white_get&＃39;,
- scope: this,
- width: 75,
- height: 24,
- handler: function() {
-
- this.submitData ( );
- }
- });
-
-
-
- submitData : function( ) {
-
- this.uploadForm.getForm().submit({
- waitMsg: &＃39;正在提交请稍后...&＃39;,
-
- url: ctx &＃43; &＃39;/testServlet, method: &＃39;POST&＃39;,
-
-
- success: function(form, action) {
-
- Ext.MessageBox.alert(&＃39;提示&＃39;, action.result.showmessage);
- },
-
- failure: function(form, action) {
- Ext.Msg.alert(&＃39;提示&＃39;, action.result.msg, function() {
- window.close();
- });
- },
- scope: this });
- }
Servlet代码:
- public class testServlet extends HttpServlet {
-
- publicvoid doPost(HttpServletRequest request, HttpServletResponse response)
- throwsServletException, IOException {
- try{
-
-
- String showMessage &＃61; new TestAction().test();
-
- response.setCharacterEncoding("UTF-8");
- response.setContentType("text/html");
- response.getWriter().write(
- "{&＃39;success&＃39;:true,&＃39;showmessage&＃39;:&＃39;"&＃43; showMessage &＃43;"&＃39;}");
-
- }catch (Exception e) {
-
- response.setCharacterEncoding("UTF-8");
- response.setContentType("text/html");
- response.getWriter().write(
- "{&＃39;success&＃39;:false,&＃39;showmessage&＃39;:&＃39;出现异常,操作失败&＃39;}");
- response.setStatus(500);
- }
-
- }
-
- publicvoid doGet(HttpServletRequest request, HttpServletResponse response)
- throwsServletException, IOException {
- doPost(request,response);
- }
- }
通过例子可以看出,success和failure方法使用的是json字符串的方式将返回值以字符串的格式通过response携带回js界面.
Ext的配置选项success、failure是根据response的status属性&＃xff0c;即状态码决定的&＃xff0c;200则为success&＃xff0c;404或500等则为failure。
EXTJS与Java后台的交互是很方便的,这里介绍的两种方法各自用在不同的场合下,根据需要来进行选择.
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