java解决跨域问题

Cross普通实现跨域请求实现：

第一种方式 ：

注解 @CrossOrigin    
           

第二种 springboot配置：

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", "HEAD", "POST", "PUT", "DELETE", "OPTIONS")
                .allowCredentials(true)
                .maxAge(3600)
                .allowedHeaders("*");
    }
}
           

第三种方式：以filter的形式

1. 在web.xml里添加以下内容

<filter>
		  <filter-name>cros</filter-name>
	           <filter-class>com.interceptor.CorsFilter</filter-class>
		  </filter>
		  <filter-mapping>
		      <filter-name>cros</filter-name>
		      <url-pattern>/*</url-pattern>
	      </filter-mapping>
     </filter>
           

2.在filter-class配置的地址下面创建CorsFilter类并添加以下内容：

import javax.servlet.*;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

public class CorsFilter implements Filter {
@Override
public void init(FilterConfig filterConfig) throws ServletException {
}

@Override
public void doFilter(ServletRequest servletRequest,
                     ServletResponse servletResponse, FilterChain filterChain)
            throws IOException, ServletException {
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        String origin = (String) servletRequest.getRemoteHost() + ":" + servletRequest.getRemotePort();
        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", "DNT,X-Mx-ReqToken,Keep-Alive,User-Agent,X-Requested-With,If-Modified-Since,Cache-Control,accept,Content-Type");
        response.setHeader("Access-Control-Allow-Credentials", "true");
        filterChain.doFilter(servletRequest, servletResponse);
    }
    @Override
    public void destroy() {
    }
 }
           

注意：在Access-Control-Allow-Headers里可以添加允许通过的Headers值，比如token校验所传递的token等。。。