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2021
09-20

Spring Cloud项目前后端分离跨域的操作

跨域问题,其实百度上面有一堆的解决方案

针对普通的情况其实百度上面的方案都是可行的。

我这里主要介绍2种情况。

当然我这里的配置都是基于网关的,而不是基于服务的。

1、没有增加权限验证。

2、增加了spring security的权限验证(我这里是基于keyCloak),增加了Authorization

首先我们介绍第一种情况的解决方法,这个很简单,只需要在启动类里面配置过滤器就可以解决。

@Bean
    public CorsFilter corsFilter() {
        //1.添加CORS配置信息
        CorsConfiguration config = new CorsConfiguration();
          //放行哪些原始域
          config.addAllowedOrigin("*");
          //是否发送Cookie信息
          config.setAllowCredentials(true);
          //放行哪些原始域(请求方式)
          config.addAllowedMethod("*");
          //放行哪些原始域(头部信息)
          config.addAllowedHeader("*");
          //暴露哪些头部信息(因为跨域访问默认不能获取全部头部信息)
          config.addExposedHeader("*");
 
        //2.添加映射路径
        UrlBasedCorsConfigurationSource configSource = new UrlBasedCorsConfigurationSource();
        configSource.registerCorsConfiguration("/**", config);
 
        //3.返回新的CorsFilter.
        return new CorsFilter(configSource);
    }

我遇到情况就是第二种了,这种情况上面的方式基本没有作用,我这里使用的是keyCloak做的权限验证。

首先增加过滤器配置:

@Component
public class CorsControllerFilter implements Filter{
	@Override
	public void destroy() {
		// TODO Auto-generated method stub
		
	}
 
	@Override
	public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
			throws IOException, ServletException {
		// TODO Auto-generated method stub
		HttpServletResponse res = (HttpServletResponse) response;
		res.setContentType("text/html;charset=UTF-8");
		res.setHeader("Access-Control-Allow-Origin", "*");
		res.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE ,PUT");
		res.setHeader("Access-Control-Max-Age", "3600");
		res.setHeader("Access-Control-Allow-Headers", "*");
		res.setHeader("Access-Control-Allow-Credentials", "true");
		res.setHeader("XDomainRequestAllowed", "1");
		chain.doFilter(request, response);
	}
 
	@Override
	public void init(FilterConfig arg0) throws ServletException {
		// TODO Auto-generated method stub	
	}
}

在启动类中增加配置

    @Bean
 public FilterRegistrationBean filterRegistrationBean() {
     FilterRegistrationBean registrationBean = new FilterRegistrationBean();
     CorsControllerFilter corsControllerFilter = new CorsControllerFilter();
     registrationBean.setFilter(corsControllerFilter);
     return registrationBean;
 }

但是针对某些请求,他会先请求OPTIONS请求,造成权限验证失败。所以增加拦截器配置,对所有的OPTIONS的请求直接放行,返回200的状态。

public class OptionsInterceptor implements HandlerInterceptor {
 
	@Override
	public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3)
			throws Exception {
		// TODO Auto-generated method stub
	}
 
	@Override
	public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3)
			throws Exception {
		// TODO Auto-generated method stub
	}
 
	@Override
	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
		// TODO Auto-generated method stub
        if(request.getMethod().equals("OPTIONS")){
            response.setStatus(HttpServletResponse.SC_OK);
            return false;
        }
        return true;
	}
}

配置web配置文件,加载拦截器。

@Configuration
public class WebMvcConfiguration extends WebMvcConfigurationSupport{
 @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new OptionsInterceptor()).addPathPatterns("/**");
 }
}

本来以为这样配置了应该是可以了,但是在请求的时候OPTIONS的请求居然还是报跨域的问题,增加拦截器允许跨域配置

public class CrossInterceptor implements HandlerInterceptor{
 @Override
 public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3)
   throws Exception {
  // TODO Auto-generated method stub
 }
 
 @Override
 public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3)
   throws Exception {
  // TODO Auto-generated method stub
 }
 
 @Override
 public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
  // TODO Auto-generated method stub
        response.setHeader("Access-Control-Allow-Origin", "*");
        response.setHeader("Access-Control-Allow-Credentials", "true");
        response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE, PUT, HEAD");
        response.setHeader("Access-Control-Allow-Headers", "*");
        response.setHeader("Access-Control-Max-Age", "3600");
        return true;
 }
}

在WebMvcConfiguration里面增加配置,注意要写在OptionsInterceptor的前面

registry.addInterceptor(new CrossInterceptor()).addPathPatterns("/**");

继续测试,跨域问题解决。对于原理其实我也不太清楚,欢迎各位沟通交流。

以上为个人经验,希望能给大家一个参考,也希望大家多多支持自学编程网。

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