跨域

1.jsonp跨域（只支持get请求）

$.ajax({

type: "get",

url: 'URL',

data: {

data: JSON.stringify(arr)

},

dataType: "jsonp",

callback: "callback",

beforeSend: function() {

$.showPreloader();

},

success: function(data) {

if(data.status == 'SUCCESS') {

$.alert('提交成功', function() {

window.location.href = 'URL';

});

}else{

$.alert('网络连接异常');

}

},

complete: function() {

$.hidePreloader();

}

});

通过jsonp可以简单处理跨域问题，我认为只要前端做出配合即可，但是存在一个问题，get请求会暴露URL上的传输参数，这样如果URL超过2KB，会导致request data 过大，无法正常与后端交互，这也只适应data数据少量的情况。

2.Tomcat配置跨域

<filter>  

    <filter-name>CORS</filter-name>  

    <filter-class>com.thetransactioncompany.cors.CORSFilter</filter-class>  

    <init-param>  

     <param-name>cors.allowOrigin</param-name>  

        <param-value>*</param-value>  

    </init-param>  

    <init-param>  

    <param-name>cors.supportedMethods</param-name>  

        <param-value>GET, POST, HEAD, PUT, DELETE</param-value>  

    </init-param>  

    <init-param>  

     <param-name>cors.supportedHeaders</param-name>  

        <param-value>Accept, Origin, X-Requested-With, Content-Type, Last-Modified</param-value>  

    </init-param>  

    <init-param>  

        <param-name>cors.exposedHeaders</param-name>  

        <param-value>Set-Cookie</param-value>  

    </init-param>  

    <init-param>  

        <param-name>cors.supportsCredentials</param-name>  

        <param-value>true</param-value>  

    </init-param>  

</filter>  

<filter-mapping>  

    <filter-name>CORS</filter-name>  

    <url-pattern>/*</url-pattern>  

</filter-mapping> 

3.修改响应头，即在后端的respone设置Http头。

@RequestMapping(value = "batchSave")

@ResponseBody

public Object acceptDataToSave(HttpServletRequest request, String data, HttpServletResponse response){

跨域的设置为蓝色背景

/**

* 采用下列方法解决post跨域问题

*/

response.addHeader("Access-Control-Allow-Origin", "*");

response.addHeader("Access-Control-Allow-Methods", "GET, POST, OPTIONS");

response.addHeader("Access-Control-Allow-Headers", "Origin, No-Cache, X-Requested-With, If-Modified-Since, Pragma, Last-Modified, Cache-Control, Expires, Content-Type, X-E4M-With");

logger.info("begin to accept data..........");

//用于返回前端的状态标示：SUCCESS为成功；FALSE为失败

String status = "FALSE";

/*

业务逻辑

...................................

*/

Map<String,String> result = new HashMap<String,String>();

result.put("status",status);

return result;

}