浅谈spring-boot 允许接口跨域并实现拦截（CORS）

// 在spring-boot-starter-web的启动器中，已经依赖好了
<dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
</dependency>

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;
import org.springframework.web.servlet.config.annotation.CorsRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
import java.util.ArrayList;
import java.util.List;
/**
 * Created by Msater Zg on 2017/4/3.
 */
@Configuration
public class CorsConfig extends WebMvcConfigurerAdapter {
  @Override
  public void addCorsMappings(CorsRegistry registry) {
    registry.addMapping("/**")
        .allowedOrigins("*")
        .allowCredentials(true)
        .allowedMethods("GET", "POST", "DELETE", "PUT")
        .maxAge(3600);
  }
  private CorsConfiguration buildConfig() {
    CorsConfiguration corsConfiguration = new CorsConfiguration();
    List<String> list = new ArrayList<>();
    list.add("*");
    corsConfiguration.setAllowedOrigins(list);
    /*
    // 请求常用的三种配置，*代表允许所有，当时你也可以自定义属性（比如header只能带什么，只能是post方式等等）
    */
    corsConfiguration.addAllowedOrigin("*"); 
    corsConfiguration.addAllowedHeader("*"); 
    corsConfiguration.addAllowedMethod("*"); 
    return corsConfiguration;
  }
  @Bean
  public CorsFilter corsFilter() {
    UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
    source.registerCorsConfiguration("/**", buildConfig());
    return new CorsFilter(source);
  }
}

import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
 * Created by Msater Zg on 2017/4/5.
 * 拦截器
 */
public class ApiInterceptor implements HandlerInterceptor {
  @Override
  public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    // 请求前调用
    System.out.println("拦截了");
    return true;
  }
  @Override
  public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
    // 请求过程中调用
    System.out.println("拦截了");
  }
  @Override
  public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {
    // 请求完成时调用
    System.out.println("拦截了");
  }
}

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.InterceptorRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
/**
 * Created by Msater Zg on 2017/4/5.
 * 拦截器管理工具
 */
@Configuration
public class MyWebAppConfigurer extends WebMvcConfigurerAdapter {
  @Override
  public void addInterceptors(InterceptorRegistry registry) {
    // 多个拦截器组成一个拦截器链
    // addPathPatterns 用于添加拦截规则
    // excludePathPatterns 用户排除拦截
    registry.addInterceptor(new ApiInterceptor()).addPathPatterns("/user/**"); //对来自/user/** 这个链接来的请求进行拦截
    super.addInterceptors(registry);
  }
}