什么是跨域问题
URL说明是否允许跨域
http:// www.a.com/a.jshttp:// www.a.com/b.js同一域名下允许http:// www.a.com/lab/a.jshttp:// www.a.com/script/b.js同一域名下不同文件夹允许http:// www.a.com:8000/a.jshttp: //www.a.com/b.js同一域名，不同端口不允许http: //www.a.com/a.jshttps: //www.a.com/b.js同一域名，不同协议不允许http:// www.a.com/a.jshttp:// 70.32.92.74/b.js域名和域名对应ip不允许http:// www.a.com/a.jshttp:// script.a.com/b.js主域相同，子域不同不允许http:// www.a.com/a.jshttp:// a.com/b.js同一域名，不同二级域名（同上）不允许http: //www.b.com/a.jshttp: //www.a.com/b.js不同域名不允许
跨域问题的本质
进程间通信的问题
Java后端解决方式
对于spring 4.2.5以上版本
/**
* 支持跨域
*
* @return
*/
@Bean
public WebMvcConfigurer
corsConfigurer() {
return new WebMvcConfigurerAdapter() {
@Override
public void addCorsMappings(CorsRegistry registry) {
registry.addMapping(
"/**").allowedOrigins(
"*").allowedMethods(
"PUT",
"DELETE",
"GET",
"POST")
.allowCredentials(
false).maxAge(
3600);
registry.addMapping(
"/login").allowedOrigins(
"*").allowedMethods(
"PUT",
"DELETE",
"GET",
"POST")
.allowCredentials(
false).maxAge(
3600);
}
};
}
对于spring 4.2.5以下版本 需要写filter来完成
package com.test.filter;
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;
/**
*
* @author hyson.han
*/
public class CorsFilter implements Filter {
@Override
public void init(FilterConfig filterConfig)
throws ServletException {
}
@Override
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain)
throws IOException, ServletException {
HttpServletResponse response = (HttpServletResponse) servletResponse;
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,Authorization");
response.setHeader(
"Access-Control-Allow-Credentials",
"true");
chain.doFilter(servletRequest, servletResponse);
}
@Override
public void destroy() {
}
}
web.xml添加如下配置
<filter>
<filter-name>cors
</filter-name>
<filter-class>com.test.filter.CorsFilter
</filter-class>
</filter>
<filter-mapping>
<filter-name>cors
</filter-name>
<url-pattern>/*
</url-pattern>
</filter-mapping>
