SpringBoot使用CROS解决跨域问题

跨域问题其实之前就有说过，不明白的可以参考我之前的文章，这章主要讲解SpringBoot CROS的支持。

这里主要按照官方文档方式讲述。

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

一、代码准备

首先是支持Restful的controller，这里就不使用数据库了，简单一点。 UserController.class

1. package cn.saytime.web;
3. import cn.saytime.bean.JsonResult;
4. import cn.saytime.bean.User;
5. import org.springframework.http.ResponseEntity;
6. import org.springframework.web.bind.annotation.CrossOrigin;
7. import org.springframework.web.bind.annotation.PathVariable;
8. import org.springframework.web.bind.annotation.RequestBody;
9. import org.springframework.web.bind.annotation.RequestMapping;
10. import org.springframework.web.bind.annotation.RequestMethod;
11. import org.springframework.web.bind.annotation.RestController;
13. import java.util.ArrayList;
14. import java.util.Collections;
15. import java.util.Date;
16. import java.util.HashMap;
17. import java.util.List;
18. import java.util.Map;
20. /**
21. * @author zh
22. * @ClassName cn.saytime.web.UserController
23. * @Description
24. */
25. @RestController
26. public class UserController {
28. // 创建线程安全的Map
29. static Map<Integer, User> users = Collections.synchronizedMap(new HashMap<Integer, User>());
31. /**
32. * 根据ID查询用户
33. * @param id
34. * @return
35. */
36. @RequestMapping(value = "user/{id}", method = RequestMethod.GET)
37. public ResponseEntity<JsonResult> getUserById (@PathVariable(value = "id") Integer id){
38. JsonResult r = new JsonResult();
39. try {
40. User user = users.get(id);
41. r.setResult(user);
42. r.setStatus("ok");
43. } catch (Exception e) {
44. r.setResult(e.getClass().getName() + ":" + e.getMessage());
45. r.setStatus("error");
46. e.printStackTrace();
47. }
48. return ResponseEntity.ok(r);
49. }
51. /**
52. * 查询用户列表
53. * @return
54. */
55. @CrossOrigin
56. @RequestMapping(value = "users", method = RequestMethod.GET)
57. public ResponseEntity<JsonResult> getUserList (){
58. JsonResult r = new JsonResult();
59. try {
60. List<User> userList = new ArrayList<User>(users.values());
61. r.setResult(userList);
62. r.setStatus("ok");
63. } catch (Exception e) {
64. r.setResult(e.getClass().getName() + ":" + e.getMessage());
65. r.setStatus("error");
66. e.printStackTrace();
67. }
68. return ResponseEntity.ok(r);
69. }
71. /**
72. * 添加用户
73. * @param user
74. * @return
75. */
76. @RequestMapping(value = "user", method = RequestMethod.POST)
77. public ResponseEntity<JsonResult> add (@RequestBody User user){
78. JsonResult r = new JsonResult();
79. try {
80. users.put(user.getId(), user);
81. r.setResult(user.getId());
82. r.setStatus("ok");
83. } catch (Exception e) {
84. r.setResult(e.getClass().getName() + ":" + e.getMessage());
85. r.setStatus("error");
87. e.printStackTrace();
88. }
89. return ResponseEntity.ok(r);
90. }
92. /**
93. * 根据id删除用户
94. * @param id
95. * @return
96. */
97. @RequestMapping(value = "user/{id}", method = RequestMethod.DELETE)
98. public ResponseEntity<JsonResult> delete (@PathVariable(value = "id") Integer id){
99. JsonResult r = new JsonResult();
100. try {
101. users.remove(id);
102. r.setResult(id);
103. r.setStatus("ok");
104. } catch (Exception e) {
105. r.setResult(e.getClass().getName() + ":" + e.getMessage());
106. r.setStatus("error");
108. e.printStackTrace();
109. }
110. return ResponseEntity.ok(r);
111. }
113. /**
114. * 根据id修改用户信息
115. * @param user
116. * @return
117. */
118. @RequestMapping(value = "user/{id}", method = RequestMethod.PUT)
119. public ResponseEntity<JsonResult> update (@PathVariable("id") Integer id, @RequestBody User user){
120. JsonResult r = new JsonResult();
121. try {
122. User u = users.get(id);
123. u.setUsername(user.getUsername());
124. u.setAge(user.getAge());
125. users.put(id, u);
126. r.setResult(u);
127. r.setStatus("ok");
128. } catch (Exception e) {
129. r.setResult(e.getClass().getName() + ":" + e.getMessage());
130. r.setStatus("error");
132. e.printStackTrace();
133. }
134. return ResponseEntity.ok(r);
135. }
137. }

User.class

1. package cn.saytime.bean;
3. import java.util.Date;
5. /**
6. * @author zh
7. * @ClassName cn.saytime.bean.User
8. * @Description
9. */
10. public class User {
12. private int id;
13. private String username;
14. private int age;
15. private Date ctm;
17. // Getter Setter
18. }

JsonResult.class

1. package cn.saytime.bean;
3. public class JsonResult {
5. private String status = null;
7. private Object result = null;
9. // Getter Setter
10. }

二、测试是否存在跨域问题

我们在static目录新建一个test.html

1. <!DOCTYPE html>
2. <html lang="en">
3. <head>
4. <meta charset="UTF-8">
5. <title>Title</title>
6. <script src="https://cdn.bootcss.com/jquery/2.1.0/jquery.min.js"></script>
7. <script type="text/javascript">
8. function crosRequest(){
9. $.ajax({
10. url:'http://localhost:8080/users',
11. type:'get',
12. dataType:'json',
13. success:function(data){
14. console.log(data);
15. }
16. });
17. }
18. </script>
19. </head>
20. <body>
21. <button onclick="crosRequest()">请求跨域资源</button>
22. </body>
23. </html>

1. 我们使用IDEA的浏览器预览功能，点击谷歌小图标，可以看到打开网址为： http://localhost:63342/springboot-demo/springboot-cros/static/test.html?_ijt=ibtt432ffb9rh0vffqkkug3je8
2. 启动SpringBoot工程，默认8080

不是使用IDEA的用户，自己找个tomcat启动test.html页面，修改端口为其他，然后启动springboot。

所以证明存在跨域问题。

一、@CrossOrigin注解方式 Controller method CORS configuration

这里我们在users映射的方法getUserList上面加上@CrossOrigin

1. @CrossOrigin
2. @RequestMapping(value = "users", method = RequestMethod.GET)
3. public ResponseEntity<JsonResult> getUserList ()

然后再次使用上面的方式访问。

表示跨域问题解决。 default @CrossOrigin allows all origins and the HTTP methods specified in the @RequestMapping annotation 上面的官方文档说明，也就是默认的@CrossOrigin允许所有跨域请求。

通过查看CrossOrigin源码可以看到， 默认配置为：

1. "Access-Control-Allow-Origin" : "*"
2. "Access-Control-Allow-Methods" : "GET,POST,PUT,OPTIONS"
3. "Access-Control-Allow-Credentials" : "true"

1. @Target({ElementType.METHOD, ElementType.TYPE})
2. @Retention(RetentionPolicy.RUNTIME)
3. @Documented
4. public @interface CrossOrigin {
5. /** @deprecated */
6. @Deprecated
7. String[] DEFAULT_ORIGINS = new String[]{"*"};
8. /** @deprecated */
9. @Deprecated
10. String[] DEFAULT_ALLOWED_HEADERS = new String[]{"*"};
11. /** @deprecated */
12. @Deprecated
13. boolean DEFAULT_ALLOW_CREDENTIALS = true;
14. /** @deprecated */
15. @Deprecated
16. long DEFAULT_MAX_AGE = 1800L;
18. @AliasFor("origins")
19. String[] value() default {};
21. @AliasFor("value")
22. String[] origins() default {};
24. String[] allowedHeaders() default {};
26. String[] exposedHeaders() default {};
28. RequestMethod[] methods() default {};
30. String allowCredentials() default "";
32. long maxAge() default -1L;
33. }

---

It is also possible to enable CORS for the whole controller 也可以用在整个Controller类上面。即该controller所有映射都支持跨域请求。

1. @CrossOrigin(origins = "http://domain2.com",
2. maxAge = 3600,
3. methods = {RequestMethod.GET, RequestMethod.POST})
4. @RestController
5. public class UserController

二、全局CORS配置

Global CORS configuration In addition to fine-grained, annotation-based configuration you’ll probably want to define some global CORS configuration as well. This is similar to using filters but can be declared withing Spring MVC and combined with fine-grained @CrossOrigin configuration. By default all origins and GET, HEAD and POST methods are allowed.

1. package cn.saytime.config;
3. import org.springframework.context.annotation.Bean;
4. import org.springframework.context.annotation.Configuration;
5. import org.springframework.web.servlet.config.annotation.CorsRegistry;
6. import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
7. import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
9. /**
10. * @author zh
11. * @ClassName cn.saytime.config.CORSConfiguration
12. * @Description
13. */
14. @Configuration
15. public class CORSConfiguration {
17. @Bean
18. public WebMvcConfigurer corsConfigurer() {
19. return new WebMvcConfigurerAdapter() {
20. @Override
21. public void addCorsMappings(CorsRegistry registry) {
22. // registry.addMapping("/api/**");
23. registry.addMapping("/**")
24. .allowedOrigins("http://domain.com", "http://domain2.com")
25. .allowedMethods("GET", "POST", "DELETE", "PUT", "OPTIONS")
26. .allowCredentials(false).maxAge(3600);
27. }
28. };
29. }
30. }

三、过滤器实现跨域 Filter based CORS support

1. @Configuration
2. public class MyConfiguration {
4. @Bean
5. public FilterRegistrationBean corsFilter() {
6. UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
7. CorsConfiguration config = new CorsConfiguration();
8. config.setAllowCredentials(false);
9. config.addAllowedOrigin("http://domain.com");
10. config.addAllowedHeader("*");
11. config.addAllowedMethod("*");
12. source.registerCorsConfiguration("/**", config);
13. FilterRegistrationBean bean = new FilterRegistrationBean(new CorsFilter(source));
14. bean.setOrder(0);
15. return bean;
16. }
17. }

原文：https://blog.csdn.net/saytime/article/details/74937204