springboot-配置跨域问题

跨域

	什么是跨域，跨域是指从不同地址或者端口发送数据获取请求，被拦截的一种现象，其根本原因是浏览器对同源资源的保护

解决方案

1.通过配置@CrossOrigin

要求如下：
1.jdk1.8+
2.spring4.2版本以上
具体代码展示如下

@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface CrossOrigin {
    /** @deprecated */
    @Deprecated
    String[] DEFAULT_ORIGINS = new String[]{"*"};
    /** @deprecated */
    @Deprecated
    String[] DEFAULT_ALLOWED_HEADERS = new String[]{"*"};
    /** @deprecated */
    @Deprecated
    boolean DEFAULT_ALLOW_CREDENTIALS = false;
    /** @deprecated */
    @Deprecated
    long DEFAULT_MAX_AGE = 1800L;

	/**
	* 同origins属性一样
	**/
    @AliasFor("origins")
    String[] value() default {};
	/**
     * 所有支持域的集合，例如"http://baidu.com"。
     * <p>这些值都显示在请求头中的Access-Control-Allow-Origin
     * "*"代表所有域的请求都支持
     * <p>如果没有定义，所有请求的域都支持
     * @see #value
     */
    @AliasFor("value")
    String[] origins() default {};

	/**
     * 允许请求头，默认都支持
     */
    String[] allowedHeaders() default {};

	/**
     * 过滤的请求头，默认为空
     */
    String[] exposedHeaders() default {};

	/**
	* 支持的请求方法GET、POST、DELETE
	* 默认支持RequestMapping中设置的方法
	*/
    RequestMethod[] methods() default {};
	/**
     * 是否允许cookie随请求发送，使用时必须指定具体的域
     */
    String allowCredentials() default "";
	/**
     * 预请求的结果的有效期，默认30分钟
     */
    long maxAge() default -1L;
}

通过如何源码分析，可以得出@CrossOrign注解默认支持所有的跨域访问，其可以配置在Controller上，也可以配置到具体的方法上，用法如下

	import com.bdcloud.bean.Email;
import com.bdcloud.response.CommonCode;
import com.bdcloud.response.ResponseResult;
import com.bdcloud.service.EmailService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;

import java.io.IOException;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@CrossOrigin
@RestController
@RequestMapping("/email")
public class EmailController {

    @Autowired
    EmailService emailService;

    @GetMapping("/getAll")
    @CrossOrigin(maxAge = 300)
    public Map getAll(){
        System.out.println("wahah");
        Map<String,Object> result = new HashMap<>();
        List<Email> allEmail = emailService.getAllEmail();
        result.put("code",0);
        result.put("count",allEmail.size());
        result.put("data",allEmail);
        return  result;
    }
}

springframeworker在5.2以后直接使用@CrossOrigin失败，具体解决方案如该篇博客

https://blog.youkuaiyun.com/shuoshuo132

2.1通过配置Filter

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
import org.springframework.web.filter.CorsFilter;

@Configuration
public class CorsConfig {
 private CorsConfiguration buildConfig() {
     CorsConfiguration corsConfiguration = new CorsConfiguration();
     corsConfiguration.addAllowedOrigin("*"); // 1允许任何域名使用
     corsConfiguration.addAllowedHeader("*"); // 2允许任何头
     corsConfiguration.addAllowedMethod("*"); // 3允许任何方法（post、get等）
     return corsConfiguration;
 }

 @Bean
 public CorsFilter corsFilter() {
     UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
     source.registerCorsConfiguration("/**", buildConfig()); // 4
     return new CorsFilter(source);
 }
}

2.1通过全局配置Filter

//统一过滤器设置
public class DomainFilter  implements Filter {
 @Override
 public void init(FilterConfig filterConfig) throws ServletException {

 }

 @Override
 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.addHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
     chain.doFilter(req, res);
 }

 @Override
 public void destroy() {

 }
}


//spring boot过滤器设置
 @Bean
 public FilterRegistrationBean filterRegistrationBean() {
     FilterRegistrationBean registrationBean = new FilterRegistrationBean();
     DomainFilter domainFilter = new DomainFilter();
     registrationBean.setFilter(domainFilter);
     List<String> urlPatterns = new ArrayList<String>();
     urlPatterns.add("/*");
     registrationBean.setUrlPatterns(urlPatterns);
     return registrationBean;
 }   

3.通过Nginx配置转发解决跨域

server {
     listen       80;
     server_name  xxx.com;
     #charset koi8-r;
     #access_log  logs/host.access.log  main;

     location /client { #访问客户端路径
         proxy_pass http://localhost:81;
         proxy_redirect default;
     }
     location /apis { #访问服务器路径
         rewrite  ^/apis/(.*)$ /$1 break;
         proxy_pass   http://localhost:82;
    }
}