AngularJS實現跨域請求

跨域，前端開發中常常遇到的問題。AngularJS實現跨域方式類似於Ajax。使用CORS機制。

以下闡述一下AngularJS中使用$http實現跨域請求數據。

AngularJS XMLHttpRequest：$http用於讀取遠程server的數據

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

一、$http.jsonp【實現跨域】

1. 指定callback和回調函數名，函數名為JSON_CALLBACK時，會調用success回調函數。JSON_CALLBACK必須全為大寫。 
2. 指定其他回調函數，但必須是定義在window下的全局函數。url中必須加上callback。 

二、$http.get【實現跨域】

1. 在server端設置同意在其它域名下訪問

response.setHeader("Access-Control-Allow-Origin", "*"); //同意全部域名訪問
response.setHeader("Access-Control-Allow-Origin", "http://www.123.com"); //同意www.123.com訪問

2. AngularJS端使用$http.get()

三、$http.post【實現跨域】

1. 在server端設置同意在其它域名下訪問，及響應類型、響應頭設置

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()，同一時候設置請求頭信息

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

四、實現方式

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。須要使用相應callback方法接收，但怎樣置於$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端支持跨域請求
public String execute(){
	response.setHeader("Access-Control-Allow-Origin", "*"); //同意哪些url能夠跨域請求到本域
	response.setHeader("Access-Control-Allow-Methods","POST"); //同意的請求方法，通常是GET,POST,PUT,DELETE,OPTIONS
	response.setHeader("Access-Control-Allow-Headers","x-requested-with,content-type"); //同意哪些請求頭能夠跨域
	
	SiteHandlerAction SiteHandler = (SiteHandlerAction) BeansFactory.getBean(SiteHandlerAction.class);
	List<IndustryCategory> list = SiteHandler.getAllIndustryCategory(); //全部的分類集合
	JSONArray jsonArray = JSONArray.fromObject(list); //將list轉為json
	String json = jsonArray.toString(); //轉為json字符串
	try {
		PrintWriter write = response.getWriter();
		write.print(json);
		write.close();
	} catch (IOException e) {
		e.printStackTrace();
	}
	return NONE;
}

<table ng-controller="getAdustryController">
	<tr ng-repeat='industry in industries'>
		<td>{{ industry.id }}</td>
		<td>{{ industry.name_ch }}</td>
		<td>{{ industry.name_eu }}</td>
		<td>{{ industry.name_jp }}</td>
	</tr>
</table>