前後端聯調跨域解決方案

public class CrosFilter implements Filter {
				
				 @Autowired
				 private AcmUtil acmUtil;	
				
				@Override
				public void init(FilterConfig filterConfig) throws ServletException {

				}

				@Override
				public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain)
						throws IOException, ServletException {

					HttpServletResponse res = (HttpServletResponse) response;
					
					String allowedOrigins = acmUtil.getValue("allowedOrigins"); // 這裏是動態從配置文件中讀取的需要跨域的ip地址
					
					if (StringUtils.isBlank(allowedOrigins)) {
						allowedOrigins = "*";
					}
					
					res.setHeader("Access-Control-Allow-Origin", allowedOrigins);
					res.setHeader("Access-Control-Allow-Headers",
							"Content-Type,Content-Length, Authorization, Accept,X-Requested-With,token");
					res.setHeader("Access-Control-Allow-Methods", "PUT,POST,GET,DELETE,OPTIONS");
					res.setHeader("Access-Control-Allow-Credentials", "true");
					res.setHeader("X-Powered-By", "Jetty");
					
					filterChain.doFilter(request, response);
				}

				@Override
				public void destroy() {

				}

跨域錯誤信息:Access to XMLHttpRequest at 'http://192.168.0.120/auth/selectOrderCount' from origin 'http://192.168.0.124:8080' has been blocked by CORS policy:
                Response to preflight request doesn't pass access control check: The 'Access-Control-Allow-Origin' header has a value 'http://192.168.0.136:8080' that is not equal to the supplied origin.

   1:      跨域看 from origin 'id地址' 和 Access-Control-Allow-Origin 中的ip地址是否一致

    2:    可以使用註解的方式跨域,在需要跨域的controller類上加到@CrossOrigin(未測試過)

    3:     如果前端傳遞token到後臺,後臺每次接收的token不一致需要在res.setHeader裏面添加token字段即可

    4:    跨域配置ip時需要加上端口號