angular的post请求，SpringMVC后台接收不到参数值的解决方案

这是我后台SpringMVC控制器接收isform参数的方法，只是简单的打出它的值：

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@RequestMapping(method = RequestMethod.POST)     @ResponseBody     public Map<String, Object> save(             @RequestParam(value = "isform", required = false) String isform) {         System.out.println("isform value: " + isform);         return null;     }

前台页面发送一个post提交表单的请求

发现后台没有取到值

后边我想到的第一种方案是在控制器方法参数里加requestbody来接收json参数，改成如下：

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@RequestMapping(method = RequestMethod.POST)     @ResponseBody     public Map<String, Object> save(             @RequestParam(value = "isform", required = false) @RequestBody String isform) {         System.out.println("isform value: " + isform);         return null;     }

但是isform的值结果还是为null，

接着我又对比了下以前的项目中，接收post请求的参数，发现一个有趣的现象，

下边是Angular的默认请求头，

$httpProvider.defaults.headers.post: (header defaults for POST requests)

Content-Type: application/json

$httpProvider.defaults.headers.put(header defaults for PUT requests)

Content-Type: application/json

其中Angular的post和put都是application/json，

而jquery的post请求的"Content-Type"默认为" application/x-www-form-urlencoded"，于是我更改了angular的默认Content-Type，

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app.config(function($httpProvider) {     $httpProvider.defaults.headers.put['Content-Type'] = 'application/x-www-form-urlencoded';     $httpProvider.defaults.headers.post['Content-Type'] = 'application/x-www-form-urlencoded'; });

接下来的请求body变成了这样，但是后边还是没有取到isform的值，

又查了半天，在一个老外的博客上发现了原因，链接如下：

http:///2012/12/20/make-angularjs-http-service-behave-like-jquery-ajax/

By default, jQuery transmits data using Content-Type: x-www-form-urlencoded and the familiar foo=bar&baz=moe serialization. AngularJS, however, transmits data using Content-Type: application/json and { "foo": "bar", "baz": "moe" } JSON serialization

自己翻译了：

默认情况下，jQuery传输数据使用Content-Type: x-www-form-urlencodedand和类似于"foo=bar&baz=moe"的序列，然而AngularJS，传输数据使用Content-Type: application/json和{ "foo": "bar", "baz": "moe" }这样的json序列。

所以下把Content-Type设置成x-www-form-urlencodedand之后，还需要转换序列的格式，

下边是我经过老外实践而自己测试过的最终方案：

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app.config(function($httpProvider) {     $httpProvider.defaults.headers.put['Content-Type'] = 'application/x-www-form-urlencoded';     $httpProvider.defaults.headers.post['Content-Type'] = 'application/x-www-form-urlencoded';     // Override $http service's default transformRequest     $httpProvider.defaults.transformRequest = [function(data) {         /**          * The workhorse; converts an object to x-www-form-urlencoded serialization.          * @param {Object} obj          * @return {String}          */         var param = function(obj) {             var query = '';             var name, value, fullSubName, subName, subValue, innerObj, i;             for (name in obj) {                 value = obj[name];                 if (value instanceof Array) {                     for (i = 0; i < value.length; ++i) {                         subValue = value[i];                         fullSubName = name + '[' + i + ']';                         innerObj = {};                         innerObj[fullSubName] = subValue;                         query += param(innerObj) + '&';                     }                 } else if (value instanceof Object) {                     for (subName in value) {                         subValue = value[subName];                         fullSubName = name + '[' + subName + ']';                         innerObj = {};                         innerObj[fullSubName] = subValue;                         query += param(innerObj) + '&';                     }                 } else if (value !== undefined && value !== null) {                     query += encodeURIComponent(name) + '='                             + encodeURIComponent(value) + '&';                 }             }             return query.length ? query.substr(0, query.length - 1) : query;         };         return angular.isObject(data) && String(data) !== '[object File]'                  param(data)                 : data;     }]; });

在angular模块中添加以上代码，我们来看下效果：

发现与jquery的post请求风格一致了，有木有！！！

看下后台的参数接收情况，

isform已经可以正常接收到参数了，大功告成！