ajax支持跨域请求

 
import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletResponse;


public class CORSFilter implements Filter{

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
            throws IOException, ServletException {
        HttpServletResponse response = (HttpServletResponse) res; 
        //允许所有访问跨域
        response.setHeader("Access-Control-Allow-Origin", "*"); 
        response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTI***, DELETE");  
        response.setHeader("Access-Control-Max-Age", "3600");  
        response.setHeader("Access-Control-Allow-Headers", "x-requested-with");  
        chain.doFilter(req, res);  
        
    }

    @Override
    public void init(FilterConfig arg0) throws ServletException {
        
    }

}

web.xml配置:

  <filter>  
    <filter-name>cors1</filter-name>  
    <filter-class>com.wms.filter.CORSFilter</filter-class>  
  </filter>  
  <filter-mapping>  
    <filter-name>cors1</filter-name>  
    <url-pattern>/*</url-pattern>  
  </filter-mapping>