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Spring Boot解决跨域问题

编辑:茕茕木偶来源:51CTO博客时间:2020-09-16 12:04:05观看:

跨域可以在前端通过 JSONP 来解决,但是 JSONP 只可以发送 GET 请求,无法发送其他类型的请求,在 RESTful 风格的应用中,就显得非常鸡肋,因此我们推荐在后端通过 (CORS,Cross-origin resource sharing) 来解决跨域问题。
https://developer.mozilla.org/zh-CN/docs/Web/HTTP/Access_control_CORS
1、通过实现WebMvcConfigurer接口然后重写addCorsMappings方法解决跨域问题。

@Configuration
public class CorsConfig implements WebMvcConfigurer {

    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")// 指定需要跨域处理的URL
                .allowedOrigins("*")// 指定允许跨越请求的host
                .allowCredentials(true)
                .allowedMethods("GET", "POST", "PUT", "DELETE", "OPTIONS")// 指定允许跨越处理的请求方法
                .maxAge(3600);
    }
}

2、通过配置CorsFilter Bean

@Configuration
public class CorsConfig {

    @Bean
    public CorsFilter corsFilter() {
        CorsConfiguration corsConfiguration = new CorsConfiguration();
        corsConfiguration.addAllowedOrigin("*");
        corsConfiguration.addAllowedHeader("*");
        corsConfiguration.addAllowedMethod("*");
        corsConfiguration.setAllowCredentials(true);
        UrlBasedCorsConfigurationSource urlBasedCorsConfigurationSource = new UrlBasedCorsConfigurationSource();
        urlBasedCorsConfigurationSource.registerCorsConfiguration("/**", corsConfiguration);
        return new CorsFilter(urlBasedCorsConfigurationSource);
    }

}

3、可通过过滤器实现CorsFilter

@Component
public class MyFilter implements Filter {

    private final static Logger logger = LoggerFactory.getLogger(MyFilter.class);

    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletResponse response = (HttpServletResponse) res;
        HttpServletRequest reqs = (HttpServletRequest) req;
        response.setHeader("Access-Control-Allow-Origin",reqs.getHeader("Origin"));
        response.setHeader("Access-Control-Allow-Credentials", "true");
        // 根据情况可以去掉delete 
        response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "x-requested-with");
        chain.doFilter(req, res);
    }
    public void init(FilterConfig filterConfig) {}
    public void destroy() {}
}

4、使用拦截器实现

public class MyInterceptor implements HandlerInterceptor {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
                response.setHeader("Access-Control-Allow-Origin", "*");
        response.setHeader("Access-Control-Allow-Methods", "*");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers",
                "Origin, X-Requested-With, Content-Type, Accept");
        return true;

    }
}

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class InterceptorRegister implements WebMvcConfigurer {
    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new MyInterceptor()).addPathPatterns("/**");
        WebMvcConfigurer.super.addInterceptors(registry);
    }
}

5、整合ApacheShiro实现跨域


import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.shiro.web.filter.authc.BasicHttpAuthenticationFilter;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.RequestMethod;

public class JWTFilter extends BasicHttpAuthenticationFilter {
    /**
     * 判断用户是否想要登入。 检测header里面是否包含Authentication-Info字段即可
     */
    @Override
    protected boolean isLoginAttempt(ServletRequest request, ServletResponse response) {
        HttpServletRequest req = (HttpServletRequest) request;
        String authorization = req.getHeader("Authentication-Info");
        return authorization != null;
    }

    @Override
    protected boolean executeLogin(ServletRequest request, ServletResponse response) throws Exception {
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        String authorization = httpServletRequest.getHeader("Authentication-Info");

        JWTToken token = new JWTToken(authorization);
        // 提交给realm进行登入,如果错误他会抛出异常并被捕获
        getSubject(request, response).login(token);
        // 如果没有抛出异常则代表登入成功,返回true
        return true;
    }

    @Override
    protected boolean isAccessAllowed(ServletRequest request, ServletResponse response, Object mappedValue) {
        if (isLoginAttempt(request, response)) {
            try {
                executeLogin(request, response);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        return true;
    }

    /**
     * 对跨域提供支持
     */
    @Override
    protected boolean preHandle(ServletRequest request, ServletResponse response) throws Exception {
        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
        HttpServletResponse httpServletResponse = (HttpServletResponse) response;
        httpServletResponse.setHeader("Access-control-Allow-Origin", httpServletRequest.getHeader("Origin"));
        httpServletResponse.setHeader("Access-Control-Allow-Methods", "GET,POST,OPTIONS,PUT,DELETE");
        httpServletResponse.setHeader("Access-Control-Allow-Headers",
                httpServletRequest.getHeader("Access-Control-Request-Headers"));
        // 跨域时会首先发送一个option请求,这里我们给option请求直接返回正常状态
        if (httpServletRequest.getMethod().equals(RequestMethod.OPTIONS.name())) {
            httpServletResponse.setStatus(HttpStatus.OK.value());
            return false;
        }
        return super.preHandle(request, response);
    }
}

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