跨域，前端开发中常常遇到的问题。AngularJS实现跨域方式类似于Ajax。使用CORS机制。

以下阐述一下AngularJS中使用$http实现跨域请求数据。

AngularJS XMLHttpRequest：$http用于读取远程server的数据$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. 指定其他回调函数，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server端设置同意在其它域名下訪问response.setHeader("Access-Control-Allow-Origin", "*"); //同意全部域名訪问

response.setHeader("Access-Control-Allow-Origin", "http://www.123.com"); //同意www.123.com訪问2. AngularJS端使用$http.get()

三、$http.post【实现跨域】

1. 在server端设置同意在其它域名下訪问，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$http.post()，同一时候设置请求头信息$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。须要使用相应callback方法接收，但怎样置于$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

public String execute(){

response.setHeader("Access-Control-Allow-Origin", "*"); //同意哪些url能够跨域请求到本域

response.setHeader("Access-Control-Allow-Methods","POST"); //同意的请求方法，通常是GET,POST,PUT,DELETE,OPTIONS

response.setHeader("Access-Control-Allow-Headers","x-requested-with,content-type"); //同意哪些请求头能够跨域

SiteHandlerAction SiteHandler = (SiteHandlerAction) BeansFactory.getBean(SiteHandlerAction.class);

List list = SiteHandler.getAllIndustryCategory(); //全部的分类集合

JSONArray jsonArray = JSONArray.fromObject(list); //将list转为json

String 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;

}