解决 ajax请求 跨域问题

解决 ajax请求 跨域问题

错误信息

在前端用ajax 请求后端 接口 时候 出现下面错误时。

Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'null' is therefore not allowed access. The response had HTTP status code 403.

什么是跨域？

简单的说即为浏览器限制访问A站点下的js代码对B站点下的url进行ajax请求。

CORS协议

CORS是一个W3C标准，全称是”跨域资源共享”（Cross-origin resource sharing）

怎么解决?

定义一个Filter　

importorg.springframework.stereotype.Component;

importjavax.servlet.*;
importjavax.servlet.http.HttpServletResponse;
importjava.io.IOException;

/**
*Created by Wuhuahui on 2016/12/13.
*/
@Component
Public class CorsFilter implements Filter{
@Override
Publicvoid init (FilterConfigfilterConfig) throws ServletException{
}

@Override
public void doFilter (ServletRequestservletRequest, ServletResponseservletResponse, FilterChainfilterChain)throws IOException ,ServletException{
HttpServletResponseresponse=(HttpServletResponse)servletResponse;
Stringorigin=(String)servletRequest.getRemoteHost()+":"+servletRequest.getRemotePort();
response.setHeader("Access-Control-Allow-Origin","*");
response.setHeader("Access-Control-Allow-Methods","POST,GET,OPTIONS,DELETE");
response.setHeader("Access-Control-Max-Age","3600");
response.setHeader("Access-Control-Allow-Headers","x-requested-with,Authorization,Origin,Content-Type,Accept");
response.setHeader("Access-Control-Allow-Credentials","true");
filterChain.doFilter(servletRequest,servletResponse);
}

@Override
Public void destroy(){
}
}

在web.xml中配置

<filter>
<filter-name>cors</filter-name>
<filter-class>top.annwz.base.filter.CorsFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>cors</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

脚注

生成一个脚注1.

目录

用

[TOC]

来生成目录：

解决 ajax请求 跨域问题
错误信息
什么是跨域

CORS协议

怎么解决

脚注

目录

这里是 脚注 的 内容. ↩