写了一个前端vue调用后端Java的接口，报“Access-Control-Allow-Origin”问题。

原因是因为在Java后端接口没有处理Access-Control-Allow-Origin.

 

① 下载处理Access-Control-Allow-Origin的2个Jar包，

然后放入 WebRoot\WEB-INF\lib下

 

②在web.xml文件添加如下

1     
      2     
     
       3         
      
       CORS
       4         
      
       com.thetransactioncompany.cors.CORSFilter
       5         
      
        6             
       
        cors.supportedHeaders
        7             
       
        Content-Type,Accept,Origin
        8         
       9         
      
       10             
       
        cors.supportedMethods
       11             
       
        GET, POST, HEAD, PUT, DELETE, OPTIONS
       12         
      13     
     14     
     
      15         
      
       CORS
      16         
      
       /*
      17     
     18     
     
      19         
      
       AccessControlFilter
      20         
      
       com.xx.xx.filter.AccessControlFilter
      21     
     22     
     
      23         
      
       AccessControlFilter
      24         
      
       *
      25     
     26     
     

 

③ 在 com.xx.xx.filter包下新建AccessControlFilter.class文件

1 package com.cdsoft.platform.filter; 2 import java.io.IOException; 3  4 import javax.servlet.Filter; 5 import javax.servlet.FilterChain; 6 import javax.servlet.FilterConfig; 7 import javax.servlet.ServletException; 8 import javax.servlet.ServletRequest; 9 import javax.servlet.ServletResponse;10 import javax.servlet.http.HttpServletResponse;11 12 13 public class AccessControlFilter implements Filter {14     @Override15     public void init(FilterConfig req) throws ServletException {16         System.out.println("Access Control Allow Init");17     }18 19     @Override20     public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain)21             throws IOException, ServletException {22         HttpServletResponse response = (HttpServletResponse)resp;23         response.setHeader("Access-Control-Allow-Origin", "*");24         chain.doFilter(req, resp);25     }26 27     @Override28     public void destroy() {29         System.out.println("Access Control Allow Destroy");30     }31 32 }

 

最后验证，运行成功！