import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
 
/**
 * AJAX請求跨域
 */
@Configuration
public class CorsConfig extends WebMvcConfigurerAdapter {
    static final String ORIGINS[] = new String[] { "GET", "POST", "PUT", "DELETE" };
    @Override
    public void addCorsMappings(CorsRegistry registry) {
    registry.addMapping("/**")
     .allowedOrigins("*")
     .allowCredentials(true)
     .allowedMethods(ORIGINS)
     .maxAge(3600);
    }

 
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.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.annotation.Configuration;
import org.springframework.stereotype.Component;
 
/**
 * 
 * @ClassName:  CorsFilter   
 * @Description: SpringBoot 跨域處理攔截器
 */
 
@Component
public class CROSFilter implements Filter {
	public static final Logger logger = LoggerFactory.getLogger(CROSFilter.class);
	
	@Override
	public void init(FilterConfig filterConfig) throws ServletException {
		// TODO Auto-generated method stub
		
	}
 
	@Override
	public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
			throws IOException, ServletException {
		HttpServletResponse response = (HttpServletResponse) res;  
		  
        HttpServletRequest reqs = (HttpServletRequest) req;  
        /*
         * 跨域設置允所有請求跨域 
         * 如果允許指定的客戶端跨域設置: http://127.0.0.1:8020
         */
        response.setHeader("Access-Control-Allow-Origin","*");  
        response.setHeader("Access-Control-Allow-Credentials", "true");  
        response.setHeader("Access-Control-Allow-Methods", "POST, GET, OPTIONS, DELETE");  
        response.setHeader("Access-Control-Max-Age", "3600");  
        response.setHeader("Access-Control-Allow-Headers", "Content-Type");  
        if (((HttpServletRequest) req).getMethod().equals("OPTIONS")) {
            response.getWriter().println("ok");
            return;
        }
 
        chain.doFilter(req, res);  
	}
 
	@Override
	public void destroy() {
		// TODO Auto-generated method stub
		
	}
 
}

  response.setHeader("Access-Control-Allow-Headers", "Content-Type");  

if (((HttpServletRequest) req).getMethod().equals("OPTIONS")) {
            response.getWriter().println("ok");
            return;
        }