调试代码遇到一个问题,就是前台运行删除操作后,controller返回数据,但前台接收时,ajax不运行success回调,总是弹出失败的对话框.接收数据类型是json.

先看看我的前台代码.

if (rows) {			$.messager.confirm('警告', '确定删除吗?', function(r) {				if (r) {					$.ajax({						type : 'post',						url : 'deleteStudentTeachClass',						data : {							"ids" : ids						},						dataType : 'json',  						traditional : true,  						success : function(result) { 														$.messager.alert("提示", "恭喜您，删除成功", "info");							$("#dg").datagrid("reload");						},						error : function(msg) {							$.messager.alert("提示", "操作失败", "info");							$("#dg").datagrid("reload");						}					});				}			});		}

以下是后台controller代码

@RequestMapping(value = "/deleteStudentTeachClass")			public void deleteStudentTeachClass(String ids, HttpServletRequest request,					HttpServletResponse response) throws Exception {										String dataBaseName = "itoo_platform";				String[] strArray = null;				strArray = ids.split(",");				Boolean flag = false;				String result = "false";				try {					flag = schoolTeachingBean.deleteStudentTeachClass(strArray,							dataBaseName);					if (flag == true) {						result = "success";					}				} catch (RuntimeException e) {					e.printStackTrace();				}				outToJson.outJson(response, result);			}

         通过查询发现dataType例如以下的说明: 

         "json": Evaluates the response as JSON and returns a JavaScript object. In jQuery 1.4 the JSON data is parsed in a strict manner; any malformed JSON is rejected and a parse error is thrown. (See json.org for more information on proper JSON formatting.) 

        也就是说jquery1.4版本号以后对json格 式要求很严格,要满足json.org站点定义的格式才干运行success回调，否则都会出错。无法解析返回的json数据.我看了下返回到前台的字符串,的确不是严格的json格式.

于是把后台返回值改成了这样:

if (flag == true) {	result = "{\"result\":true}";}

但不管返回true还是false都运行success回调,这让我更郁闷.百思不得其解.

终于把前台推断改成了这样:

if (rows) {			$.messager.confirm('警告', '确定删除吗?', function(r) {				if (r) {					$.ajax({						type : 'post',						url : 'deleteStudentTeachClass',						data : {							"ids" : ids						},						dataType : 'text',  						traditional : true,  						success : function(result) {														if(result=='true'){								$.messager.alert("提示", "恭喜您，删除成功", "info");								$("#dg").datagrid("reload");								}							else{								$.messager.alert("提示", "操作失败", "info");								$("#dg").datagrid("reload");								}						}											});				}			});		}