Springboot跨域处理
1. 为什么出现跨域
浏览器同源策略限制。 同源策略(Same Origin Policy): 是一种约束;浏览器最核心也是最基础的安全功能。缺少了同源策略,浏览器正常功能都可能受影响。 同源策略阻止一个域的javaScript脚本和另一个域的内进行交互。所谓同源就是两个页面具有相同的协议(protocol)、主机(host)和端口号(port)。
非同源限制: 【1】无法读取非同源网页的 Cookie、LocalStorage 和 IndexedDB 【2】无法接触非同源网页的 DOM 【3】无法向非同源地址发送 AJAX 请求
Java 后端实现CORS跨域请求:
- 返回新的CorsFilter
- 重写 WebMvcConfigurer
- 使用注解 @CrossOrigin
- 手动设置响应头 (HttpServletResponse)
- 自定web filter 实现跨域
2.跨域处理
# 1.返回新的CorsFilter(全局跨域)
@Configuration
public class GlobalCorsConfig {
@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
config.setAllowCredentials(true);
//放行哪些请求方式
config.addAllowedMethod("*");
//放行哪些原始请求头部信息
config.addAllowedHeader("*");
//暴露哪些头部信息
config.addExposedHeader("*");
//2. 添加映射路径
UrlBasedCorsConfigurationSource corsConfigurationSource = new UrlBasedCorsConfigurationSource();
corsConfigurationSource.registerCorsConfiguration("/**",config);
//3. 返回新的CorsFilter
return new CorsFilter(corsConfigurationSource);
}
}
# 2.重写WebMvcConfigurer(全局跨域)
@Configuration
public class CorsConfig implements WebMvcConfigurer {
@Override
public void addCorsMappings(CorsRegistry registry) {
registry.addMapping("/**")
//是否发送Cookie
.allowCredentials(true)
//放行哪些原始域
.allowedOrigins("*")
.allowedMethods(new String[]{"GET", "POST", "PUT", "DELETE"})
.allowedHeaders("*")
.exposedHeaders("*");
}
}
# 3.使用注解 --在类上使用,允许类下方法跨域
@RestController
@CrossOrigin(origins = "*")
public class HelloController {
@RequestMapping("/hello")
public String hello() {
return "hello world";
}
}
# 4.编写一个过滤器,起名叫MyCorsFilter.java
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletResponse;
import org.springframework.stereotype.Component;
@Component
public class MyCorsFilter implements Filter {
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-Methods", "POST, GET, OPTIONS, DELETE");
response.setHeader("Access-Control-Max-Age", "3600");
response.setHeader("Access-Control-Allow-Headers", "x-requested-with,content-type");
chain.doFilter(req, res);
}
public void init(FilterConfig filterConfig) {}
public void destroy() {}
}
<!-- web.xml中配置跨域访问 -->
<filter>
<filter-name>CorsFilter</filter-name>
<filter-class>com.mesnac.aop.MyCorsFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>CorsFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
5. 前端使用jsonp进行跨域:
# 在nginx/conf/ 目录下,新增enable-cors.conf文件
# allow origin list
set $ACAO '*';
# set single origin
if ($http_origin ~* (www.helloworld.com)$) { #网站域名
set $ACAO $http_origin;
}
if ($cors = "trueget") {
add_header 'Access-Control-Allow-Origin' "$http_origin";
add_header 'Access-Control-Allow-Credentials' 'true';
add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS';
add_header 'Access-Control-Allow-Headers' 'DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,Content-Type';
}
if ($request_method = 'OPTIONS') {
set $cors "${cors}options";
}
if ($request_method = 'GET') {
set $cors "${cors}get";
}
if ($request_method = 'POST') {
set $cors "${cors}post";
}
<!-- 在nginx.conf文件中添加配置 -->
upstream front_server{
server www.helloworld.com:9000;
}
upstream api_server{
server www.helloworld.com:8080;
}
server {
listen 80;
server_name www.helloworld.com;
location ~ ^/api/ { <!--后端的映射-->
include enable-cors.conf; <!--引入新增的配置信息-->
proxy_pass http://api_server;
rewrite "^/api/(.*)$" /$1 break;
}
location ~ ^/ {
proxy_pass http://front_server;
}
}