java：springboot后台解决接口跨域问题

首先启动类上肯定需要声明跨域

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration;
import org.springframework.web.bind.annotation.CrossOrigin;

@CrossOrigin   //声明跨域
@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
public class AppApplication implements CommandLineRunner {

    Logger logger = LoggerFactory.getLogger(this.getClass());

    public static void main(String[] args) {
        SpringApplication.run(AppApplication.class, args);
    }

    @Override
    public void run(String... args) throws Exception {
        logger.info("服务启动完成!");
    }
}

编写配置类直接跨域：CORSFilter 实现了拦截器，允许放行

import org.springframework.stereotype.Component;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
*@Description 解决跨域问题
*@Author 
*@Date 2020/4/8
*/
@Component
public class CORSFilter implements Filter {

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        HttpServletResponse res = (HttpServletResponse) response;
        res.addHeader("Access-Control-Allow-Credentials", "true");
        res.addHeader("Access-Control-Allow-Origin", "*");
        res.addHeader("Access-Control-Allow-Methods", "GET, POST, DELETE, PUT");
        res.addHeader("Access-Control-Allow-Headers", "Content-Type,X-CAF-Authorization-Token,sessionToken,X-TOKEN");
        if (((HttpServletRequest) request).getMethod().equals("OPTIONS")) {
            response.getWriter().println("ok");
            return;
        }
        chain.doFilter(request, response);
    }
    @Override
    public void destroy() {
    }
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }
}

再写一个类支持ajax请求

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

/**
*@Description AJAX请求跨域，
	重写WebMvcConfigurerAdapter的addCorsMappings方法就可以获得基于spring的跨域支持
*@Author
*@Date 2020/4/8
*/
@Configuration
public class CrossOriginConfig 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);
    }
}