SpringBoot解决跨域

请求发起人与被请求人必须拥有相同的协议、主机地址以及端口，一旦这三项数据中有一项不同，那么该请求便是跨域请求。
解决方法：

1. 使用@CrossOrigin注解:
   注解可以放在method、class等上面，可以控制整个controller，也可以控制单个方法，这个是最小粒度的控制方法。

@CrossOrigin(origins = "请求的协议://请求的地址:请求的端口", maxAge = 3600)

2. 配置自定义过滤器:

import org.springframework.context.annotation.Configuration;
import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebFilter(filterName = "CorsFilter ")
@Configuration
public class CorsFilter implements Filter {
    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletResponse response = (HttpServletResponse) res;
        response.setHeader("Access-Control-Allow-Origin","*");
        response.setHeader("Access-Control-Allow-Credentials", "true");
        response.setHeader("Access-Control-Allow-Methods", "POST, GET, PATCH, DELETE, PUT");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
        chain.doFilter(req, res);
    }
}

3. 自定义WebMvcConfigurer配置全局属性

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

@Configuration
public class CorsConfig implements WebMvcConfigurer {

    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedOrigins("*")
                .allowedMethods("GET", "POST", "PUT", "DELETE", "OPTIONS")
                .allowCredentials(true)
                .maxAge(3600)
                .allowedHeaders("*");
    }
}

2020-02-25