关于JS调用Java后台API跨域问题的解决方法

public class CORSFilter implements Filter {

public void init(FilterConfig filterConfig) throws ServletException {

}

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
HttpServletResponse res = (HttpServletResponse) response;
   HttpServletRequest request1 = (HttpServletRequest) request;
   String ip = request1.getHeader("Origin");
   res.setContentType("text/html;charset=UTF-8");
   res.setHeader("Access-Control-Allow-Origin", ip);
res.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
res.setHeader("Access-Control-Max-Age", "0");
res.setHeader("Access-Control-Allow-Headers",
"Origin, No-Cache, X-Requested-With, If-Modified-Since, Pragma, Last-Modified, Cache-Control, Expires, Content-Type, X-E4M-With,userId,token");
res.setHeader("Access-Control-Allow-Credentials", "true");
res.setHeader("XDomainRequestAllowed", "1");
chain.doFilter(request, response);
}

public void destroy() {
// TODO Auto-generated method stub

}

}

<filter>
<filter-name>CORSFilter</filter-name>
<filter-class>CORSFilter全限定名</filter-class>
</filter>
<filter-mapping>
<filter-name>CORSFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>