Cannot invoke"org.springframework.web.client.RestTemplate.getForEntity(String, java.lang.Class, Object[])""this.restTemplate"null

huangapple
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英文:

Cannot invoke"org.springframework.web.client.RestTemplate.getForEntity(String, java.lang.Class, Object[])""this.restTemplate"null

问题

我正在开发一个tokenValidationInterceptor，其中会向另一个微服务发送令牌验证请求，该微服务与Keycloak通信并返回正常状态或未授权状态。然后，我在prehandle函数中添加了一些逻辑，就是这样。当我尝试测试它时，我得到了这个错误：

  1. java.lang.NullPointerException: Cannot invoke "org.springframework.web.client.RestTemplate.getForEntity(String, java.lang.Class, Object[])" because "this.restTemplate" is null

TokenValidationInterceptor的preHandle方法：

  1. public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
  2.     String token = request.getHeader(HttpHeaders.AUTHORIZATION);
  3.     String verificationUrl = "http://localhost:8090/user/info?token=" + token;
  4.     ResponseEntity<Boolean> verificationResponse = restTemplate.getForEntity(verificationUrl, Boolean.class);
  5.     if (verificationResponse.getStatusCode() == HttpStatus.OK && verificationResponse.getBody() != null && verificationResponse.getBody()) {
  6.         return true;
  7.     } else {
  8.         response.setStatus(HttpStatus.UNAUTHORIZED.value());
  9.         return false;
  10.     }
  11. }

Appconfig：

  1. @Configuration
  2. public class AppConfig implements WebMvcConfigurer {
  4.     @Override
  5.     public void addInterceptors(InterceptorRegistry registry) {
  6.         registry.addInterceptor(new TokenValidationInterceptor());
  7.     }
  9.     @Bean
  10.     public RestTemplate restTemplate() {
  11.         return new RestTemplate();
  12.     }
  14. }

另一个微服务中的令牌验证：

  1. public ResponseEntity<?> verifyToken(String token) {
  2.     String keycloakUrl = "http://localhost:8080/auth/realms/lbv-realm/protocol/openid-connect/userinfo";
  3.     if (token != null) {
  4.         HttpHeaders headers = new HttpHeaders();
  5.         headers.setBearerAuth(token);
  6.         HttpEntity<String> requestEntity = new HttpEntity<>(headers);
  7.         RestTemplate restTemplate = new RestTemplate();
  8.         try {
  9.             ResponseEntity<String> response = restTemplate.exchange(keycloakUrl, HttpMethod.GET, requestEntity, String.class);
  10.             HttpStatus statusCode = response.getStatusCode();
  11.             if (statusCode.is2xxSuccessful()) {
  12.                 return ResponseEntity.status(HttpStatus.OK).body(true);
  13.             } else {
  14.                 return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body(false);
  15.             }
  16.         } catch (Exception ex) {
  17.             return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body(false);
  18.         }
  19.     } else {
  20.         return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body(false);
  21.     }
  22. }

请注意，我已经将HTML编码的引号(&quot;)更改为普通的双引号(")以便于代码的理解。

英文:

i'm working on an tokenValidationInterceptor , where a request for token validation is send to an other micro-service which communicate with keycloak and send an ok status or unautorazed status , then i add some logic to the prehandle function and that's all , when i try to test it, i get this error :

  1. java.lang.NullPointerException: Cannot invoke &quot;org.springframework.web.client.RestTemplate.getForEntity(String, java.lang.Class, Object[])&quot; because &quot;this.restTemplate&quot; is null

TokenValidationInterceptor prehandle method

  1.     public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
  2.         String token = request.getHeader(HttpHeaders.AUTHORIZATION);
  3.         String verificationUrl = &quot;http://localhost:8090/user/info?token=&quot; + token;
  4.         ResponseEntity&lt;Boolean&gt; verificationResponse = restTemplate.getForEntity(verificationUrl, Boolean.class);
  5.         if (verificationResponse.getStatusCode() == HttpStatus.OK &amp;&amp; verificationResponse.getBody() != null &amp;&amp; verificationResponse.getBody()) {
  6.             return true;
  7.         } else {
  8.             response.setStatus(HttpStatus.UNAUTHORIZED.value());
  9.             return false;
  10.         }
  11.     }

Appconfig

  1. @Configuration
  2. public class AppConfig implements WebMvcConfigurer {
  4.     @Override
  5.     public void addInterceptors(InterceptorRegistry registry) {
  6.         registry.addInterceptor( new TokenValidationInterceptor());
  7.     }
  9.     @Bean
  10.     public RestTemplate restTemplate() {
  11.         return new RestTemplate();
  12.     }
  14. }

and for the tokenValidation in the other micro-service

  1. public ResponseEntity&lt;?&gt; verifyToken(String token) {
  2.             String keycloakUrl = &quot;http://localhost:8080/auth/realms/lbv-realm/protocol/openid-connect/userinfo&quot;;
  3.             if (token != null) {
  4.                 HttpHeaders headers = new HttpHeaders();
  5.                 headers.setBearerAuth(token);
  6.                 HttpEntity&lt;String&gt; requestEntity = new HttpEntity&lt;&gt;(headers);
  7.                 RestTemplate restTemplate = new RestTemplate();
  8.                 try {
  9.                     ResponseEntity&lt;String&gt; response = restTemplate.exchange(keycloakUrl, HttpMethod.GET, requestEntity, String.class);
  10.                     HttpStatusCode statusCode = response.getStatusCode();
  11.                     if (statusCode.is2xxSuccessful()) {
  12.                         return ResponseEntity.status(HttpStatus.OK).body(true);
  13.                     } else {
  14.                         return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body(false);
  15.                     }
  16.                 } catch (Exception ex) {
  17.                     return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body(false);
  18.                 }
  19.             } else {
  20.                 return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body(false);
  21.             }
  22.     }

答案1

得分: 0

如果您的 restTemplate 为null，您可以通过构造函数或 @Autowired 注解来简单地注入 RestTemplate。

  1. @Autowired
  2. private RestTemplate restTemplate;

或者

  1. public class YourClass {
  3.     private final RestTemplate restTemplate;
  5.     public YourClass(RestTemplate restTemplate) {
  6.         this.restTemplate = restTemplate;
  7.     }
  9. }
英文:

If your restTemplate is null,you can simply inject RestTemplate through constructor or @Autowired annotation.

  1. @Autowired
  2. private RestTemplate restTemplate;

or

  1. public class YourClass{
  3. private final RestTemplate restTemplate;
  5. public YourClass(RestTemplate restTemplate){
  6. this.restTemplate=restTemplate;
  7. }
  9. }

huangapple
  • 本文由 发表于 2023年7月13日 18:28:09
  • 转载请务必保留本文链接：https://go.coder-hub.com/76678357.html
  • java
  • keycloak
  • microservices
  • spring-boot
  • spring-resttemplate
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