AngularJS实现跨域请求

跨域，前端开发中经常遇到的问题，AngularJS实现跨域方式类似于Ajax，使用CORS机制。
下面阐述一下AngularJS中使用$http实现跨域请求数据。

AngularJS XMLHttpRequest：$http用于读取远程服务器的数据

$http.post(url, data, [config]).success(function(){ ... });$http.get(url, [config]).success(function(){ ... });$http.get(url, [config]).success(function(){ ... });

一、$http.jsonp【实现跨域】

1. 指定callback和回调函数名，函数名为JSON_CALLBACK时，会调用success回调函数，JSON_CALLBACK必须全为大写。
2. 指定其它回调函数，但必须是定义在window下的全局函数。url中必须加上callback。

二、$http.get【实现跨域】

1. 在服务器端设置允许在其他域名下访问

response.setHeader("Access-Control-Allow-Origin", "*"); //允许所有域名访问response.setHeader("Access-Control-Allow-Origin", "http://www.123.com"); //允许www.123.com访问

2. AngularJS端使用$http.get()

三、$http.post【实现跨域】

1. 在服务器端设置允许在其他域名下访问，及响应类型、响应头设置 

response.setHeader("Access-Control-Allow-Origin", "*");response.setHeader("Access-Control-Allow-Methods","POST");response.setHeader("Access-Control-Allow-Headers","x-requested-with,content-type");

2. AngularJS端使用$http.post()，同时设置请求头信息

$http.post('http://localhost/ajax/getAllIndustryCategoty.pt',{languageColumn:'name_eu'},{'Content-Type':'application/x-www-form-urlencoded'}).success(function(data){$scope.industries = data;});

四、实现方式

跨域方式一【JSONP】：

方法一：

$http.jsonp("http://localhost/sitesettings/getBadgeInfo.pt?jsonp=JSON_CALLBACK&siteid=137bd406").success(function(data){ ... });//  The name of the callback should be the string JSON_CALLBACK.

方法二【返回值，需要使用对应callback方法接收，但如何置于$scope???】：

$http.jsonp("http://localhost/sitesettings/getBadgeInfo.pt?jsonp=badgeabc&siteid=137bd406");function badgeabc(data){ ... }

public String execute() throws Exception {String result = FAIL;response.setHeader("", "");SiteHandlerAction siteHandlerAction = (SiteHandlerAction)BeansFactory.getBean(SiteHandlerAction.class);BadgeHandlerAction badgeHandlerAction = (BadgeHandlerAction)BeansFactory.getBean(BadgeHandlerAction.class);if("".equals(siteid) || siteid == null || StringUtils.isBlank("jsonp")){result = FAIL;}else{Site site = siteHandlerAction.find(siteid);UserBadgeStatus userBadgeStatus = badgeHandlerAction.getUserBadgeStatus(site.getId());if(userBadgeStatus != null){result = "{\"t\":"+userBadgeStatus.getStyle()+",\"l\":"+userBadgeStatus.getSuspend_location()+",\"s\":"+site.getId()+"}";JSONObject jsonObj = JSONObject.fromObject(result);String json = jsonObj.toString();result = jsonp + "(" + json + ")";}}PrintWriter write = response.getWriter();write.print(result);write.flush();write.close();return NONE;}

跨域方式二【$http.get()】：

function getAdustryController($scope,$http){$http.get('http://localhost/ajax/getAllIndustryCategoty.pt?languageColumn=name_eu').success(function(data){$scope.industries = data;});}

跨域方式三【$http.post()】：

function getAdustryController($scope,$http){$http.post('http://localhost/ajax/getAllIndustryCategoty.pt',{languageColumn:'name_eu'},{'Content-Type':'application/x-www-form-urlencoded'}).success(function(data){$scope.industries = data;});}

java端支持跨域请求

<pre name="code" class="html">// java端支持跨域请求public String execute(){response.setHeader("Access-Control-Allow-Origin", "*"); //允许哪些url可以跨域请求到本域response.setHeader("Access-Control-Allow-Methods","POST"); //允许的请求方法，一般是GET,POST,PUT,DELETE,OPTIONSresponse.setHeader("Access-Control-Allow-Headers","x-requested-with,content-type"); //允许哪些请求头可以跨域SiteHandlerAction SiteHandler = (SiteHandlerAction) BeansFactory.getBean(SiteHandlerAction.class);List list = SiteHandler.getAllIndustryCategory(); //所有的分类集合JSONArray jsonArray = JSONArray.fromObject(list); //将list转为jsonString json = jsonArray.toString(); //转为json字符串try {PrintWriter write = response.getWriter();write.print(json);write.close();} catch (IOException e) {e.printStackTrace();}return NONE;}