如何将 Angular 2 与 Spring Boot 应用程序连接起来？答案

【问题标题】：How to connect Angular 2 with Spring boot application?如何将 Angular 2 与 Spring Boot 应用程序连接起来？
【发布时间】：2020-11-29 09:37:50
【问题描述】：

我使用 HttpModule 发送 post 请求以将登录凭据发送到 Spring 框架应用程序，但该请求被 spring security 过滤掉了。Angular 应用程序不是发送 post 请求，而是发送一些“选项”请求。

下面的代码是做什么的？

public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) {
        HttpServletResponse response = (HttpServletResponse) res;
        HttpServletRequest request = (HttpServletRequest) req;

        response.setHeader("Access-Control-Allow-Origin", "http://localhost:4200");
        response.setHeader("Access-Control-Allow-Methods", "POST, PUT, GET, OPTIONS, DELETE");
        response.setHeader("Access-Control-Allow-Headers", "x-requested-with");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Credentials", "true");

        if (!(request.getMethod().equalsIgnoreCase("OPTIONS"))) {
            try {
                chain.doFilter(req, res);
            } catch(Exception e) {
                e.printStackTrace();
            }
        } else {
            System.out.println("Pre-flight");
            response.setHeader("Access-Control-Allow-Methods", "POST,GET,DELETE");
            response.setHeader("Access-Control-Max-Age", "3600");
            response.setHeader("Access-Control-Allow-Headers", "authorization, content-type," +
                    "access-control-request-headers,access-control-request-method,accept,origin,authorization,x-requested-with");
            response.setStatus(HttpServletResponse.SC_OK);
        }

    }

【问题讨论】：

标签： angular spring spring-security angular-httpclient

【解决方案1】：

您的 CORS 配置仅允许来自

的流量

 response.setHeader("Access-Control-Allow-Origin", "http://localhost:4200");

确保您的 Angular 客户端正在该特定主机和端口上运行。

浏览器最初发出 HTTP OPTIONS (CORS pre-flight) 请求以验证客户端主机/端口是否与服务器的响应匹配（即您设置的 Access-Control-Allow-Origin 响应标头的值)

【讨论】：

谢谢，我了解 CORS 的工作原理。它只是在发送实际请求之前进行检查。下面的代码有什么作用？ System.out.println("飞行前"); response.setHeader("Access-Control-Allow-Methods", "POST,GET,DELETE"); response.setHeader("Access-Control-Max-Age", "3600"); response.setHeader("Access-Control-Allow-Headers", "authorization, content-type," + "access-control-request-headers,access-control-request-method,accept,origin,authorization,x-requested-和”）; response.setStatus(HttpServletResponse.SC_OK);
它们指定了http请求方法和服务器允许从客户端接受的请求头。