教你用Java SpringBoot如何解决跨域

package com.example.crossdomain.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

package com.example.crossdomain.demo.controller;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RequestMapping("/demo")
@RestController
@CrossOrigin("https://blog.csdn.net") // 只有指定域名可以访问该类下所有接口
public class CorsTestController {
    @GetMapping("/sayHello")
    public String sayHello(){
        return "Hello world";
    }
}

package com.example.crossdomain.demo.config;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.CorsReGIStry;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
@Configuration
@EnableWebMvc
public class CorsConfiguration extends WebMvcConfigurerAdapter {
    @Override
    public void addCorsMappings(CorsRegistry registry) {
        registry.addMapping("/**")
                .allowedMethods("GET", "POST");
    }
}

package com.example.crossdomain.demo.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.*;
@Configuration
public class CorsConfiguration
{
    @Bean
    public WebMvcConfigurer corsConfigurer()
    {
        return new WebMvcConfigurerAdapter() {
            @Override
            public void addCorsMappings(CorsRegistry registry) {
                registry.addMapping("/**");
            }
        };
    }
}

package com.example.crossdomain.demo.config;

import org.springframework.context.annotation.Bean;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.CorsConfigurationSource;
import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
import java.util.Arrays;
@EnableWebSecurity
public class WebSecurityConfig extends WebSecurityConfigurerAdapter {
    @Override
    protected void configure(HttpSecurity http) throws Exception {
        http.cors();
    }
    @Bean
    CorsConfigurationSource corsConfigurationSource()
    {
        CorsConfiguration corsConfiguration = new CorsConfiguration();
        corsConfiguration.addAllowedOrigin("*");	//同源配置，*表示任何请求都视为同源，若需指定ip和端口可以改为如“localhost：8080”，多个以“，”分隔；
        corsConfiguration.addAllowedHeader("*");//header，允许哪些header，本案中使用的是token，此处可将*替换为token；
        corsConfiguration.addAllowedMethod("*");	//允许的请求方法，PSOT、GET等
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        source.registerCorsConfiguration("/**", corsConfiguration);
        return source;
    }
}