java web 之springboot教程(八)----CROS解决跨域问题

SpringBoot CROS 参考： http://docs.spring.io/spring-boot/docs/1.5.4.RELEASE/reference/htmlsingle/#boot-features-cors

Spring CROS 参考： http://docs.spring.io/spring/docs/4.3.9.RELEASE/spring-framework-reference/htmlsingle/#cors

首先是支持Restful的controller。保持原来的UserController.java；在getUserList()方法上添加@CrossOrigin注解

package com.cx.springbootdemo.controller;

import com.cx.springbootdemo.pojo.JsonResult;
import com.cx.springbootdemo.pojo.User;
import com.cx.springbootdemo.service.UserMapperService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@RestController
public class UserController {

    @Autowired
    private UserMapperService userService;

    /**
     * 根据ID查询用户
     * @param id
     * @return
     */
    @RequestMapping(value = "user/{id}", method = RequestMethod.GET)
    public ResponseEntity<JsonResult> getUserById (@PathVariable(value = "id") Integer id){
        JsonResult r = new JsonResult();
        try {
            User user = userService.getUserById(id);
            r.setResult(user);
            r.setStatus("ok");
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");
            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }

    /**
     * 查询用户列表
     * @return
     */
    @CrossOrigin
    @RequestMapping(value = "users", method = RequestMethod.GET)
    public ResponseEntity<JsonResult> getUserList (){
        JsonResult r = new JsonResult();
        try {
            List<User> users = userService.getUserList();
            r.setResult(users);
            r.setStatus("ok");
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");
            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }

    /**
     * 添加用户
     * @param user
     * @return
     */
    @RequestMapping(value = "user", method = RequestMethod.POST)
    public ResponseEntity<JsonResult> add (@RequestBody User user){
        JsonResult r = new JsonResult();
        try {
            int orderId = userService.add(user);
            if (orderId < 0) {
                r.setResult(orderId);
                r.setStatus("fail");
            } else {
                r.setResult(orderId);
                r.setStatus("ok");
            }
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");

            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }

    /**
     * 根据id删除用户
     * @param id
     * @return
     */
    @RequestMapping(value = "user/{id}", method = RequestMethod.DELETE)
    public ResponseEntity<JsonResult> delete (@PathVariable(value = "id") Integer id){
        JsonResult r = new JsonResult();
        try {
            int ret = userService.delete(id);
            if (ret < 0) {
                r.setResult(ret);
                r.setStatus("fail");
            } else {
                r.setResult(ret);
                r.setStatus("ok");
            }
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");

            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }

    /**
     * 根据id修改用户信息
     * @param user
     * @return
     */
    @RequestMapping(value = "user/{id}", method = RequestMethod.PUT)
    public ResponseEntity<JsonResult> update (@PathVariable("id") Integer id, @RequestBody User user){
        JsonResult r = new JsonResult();
        try {
            int ret = userService.update(id, user);
            if (ret < 0) {
                r.setResult(ret);
                r.setStatus("fail");
            } else {
                r.setResult(ret);
                r.setStatus("ok");
            }
        } catch (Exception e) {
            r.setResult(e.getClass().getName() + ":" + e.getMessage());
            r.setStatus("error");

            e.printStackTrace();
        }
        return ResponseEntity.ok(r);
    }

}

来测试下是否存在跨域问题：

在static目录新建一个test.html；

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="https://cdn.bootcss.com/jquery/2.1.0/jquery.min.js"></script>
    <script type="text/javascript">
        function crosRequest(){
            $.ajax({
                url:'http://localhost:8888/users',
                type:'get',
                dataType:'json',
                success:function(data){
                    console.log(data);
                }
            });
        }
    </script>
</head>
<body>
<button onclick="crosRequest()">请求跨域资源</button>
</body>
</html>

先把UserController中的@CrossOrigin注释掉，然后在chrome浏览器中测试下，按F12查看：

然后再把@CrossOrigin打开：

 确实存在跨域问题，通过添加@CrossOrigin解决了。

这是第一种方法。

这种方法也可以注解到controller上：

@CrossOrigin(origins = "*",
        maxAge = 3600,
        methods = {RequestMethod.GET, RequestMethod.POST})
@RestController
public class UserController {

第二种方法：全局CORS配置

 

在core下面新建一个CORSConfiguration类：

package com.cx.springbootdemo.core;

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

@Configuration
public class CORSConfiguration {

    @Bean
    public WebMvcConfigurer corsConfigurer() {
        return new WebMvcConfigurerAdapter() {
            @Override
            public void addCorsMappings(CorsRegistry registry) {
//				registry.addMapping("/api/**");
                registry.addMapping("/**")
//                        .allowedOrigins("http://domain.com", "http://domain2.com")
                        .allowedOrigins("*")
                        .allowedMethods("GET", "POST", "DELETE", "PUT", "OPTIONS")
                        .allowCredentials(false).maxAge(3600);
            }
        };
    }
}

 第三种方法：过滤器实现跨域

在core目录下新建MyConfiguration.java

package com.cx.springbootdemo.core;


import org.springframework.boot.web.servlet.FilterRegistrationBean;
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 MyConfiguration {

    @Bean
    public FilterRegistrationBean corsFilter() {
        UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
        CorsConfiguration config = new CorsConfiguration();
        config.setAllowCredentials(false);
//        config.addAllowedOrigin("http://domain.com");
        config.addAllowedOrigin("*");
        config.addAllowedHeader("*");
        config.addAllowedMethod("*");
        source.registerCorsConfiguration("/**", config);
        FilterRegistrationBean bean = new FilterRegistrationBean(new CorsFilter(source));
        bean.setOrder(0);
        return bean;
    }
}

以上均测试通过。