无法执行CommandLineRunner-Spring Boot

Question

我刚接触Spring，正在处理这个问题。

它抛出一个异常:

尝试执行CommandLineRunner时失败。

我已经尝试了几种方法，但在控制台中的结果仍然是一样的：

java.lang.IllegalStateException: Failed to execute CommandLineRunner
at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:774) ~[spring-boot-2.7.4.jar:2.7.4]
at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:755) ~[spring-boot-2.7.4.jar:2.7.4]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) ~[spring-boot-2.7.4.jar:2.7.4]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1306) ~[spring-boot-2.7.4.jar:2.7.4]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1295) ~[spring-boot-2.7.4.jar:2.7.4]
at io.getarrays.userservice.UserserviceApplication.main(UserserviceApplication.java:19) ~[classes/:na]
Caused by: java.lang.NullPointerException: Cannot invoke "io.getarrays.userservice.domain.User.getRoles()" because "user" is null
at io.getarrays.userservice.service.UserServiceImpl.addRoleToUser(UserServiceImpl.java:36) ~[classes/:na]
at io.getarrays.userservice.service.UserServiceImpl$$FastClassBySpringCGLIB$$cf86a147.invoke(<generated>) ~[classes/:na]
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) ~[spring-core-5.3.23.jar:5.3.23]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:793) ~[spring-aop-5.3.23.jar:5.3.23]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.3.23.jar:5.3.23]
at `Datos en Consola`org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:763) ~[spring-aop-5.3.23.jar:5.3.23]
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:123) ~[spring-tx-5.3.23.jar:5.3.23]
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:388) ~[spring-tx-5.3.23.jar:5.3.23]
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:119) ~[spring-tx-5.3.23.jar:5.3.23]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.23.jar:5.3.23]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:763) ~[spring-aop-5.3.23.jar:5.3.23]
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:708) ~[spring-aop-5.3.23.jar:5.3.23]
at io.getarrays.userservice.service.UserServiceImpl$$EnhancerBySpringCGLIB$$4c838cf9.addRoleToUser(<generated>) ~[classes/:na]
at io.getarrays.userservice.UserserviceApplication.lambda$run$0(UserserviceApplication.java:35) ~[classes/:na]
at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:771) ~[spring-boot-2.7.4.jar:2.7.4]
... 5 common frames omitted

代码：

@SpringBootApplication
public class UserserviceApplication {

    public static void main(String[] args) {
        SpringApplication.run(UserserviceApplication.class, args);
    }

    @Bean
    CommandLineRunner run(UserService userService){
        return args -> {

保存角色

            userService.saveRole(new Role(null, "ROLE_USER"));
            userService.saveRole(new Role(null, "ROLE_MANAGER"));
            userService.saveRole(new Role(null, "ROLE_ADMIN"));
            userService.saveRole(new Role(null, "ROLE_SUPER_ADMIN"));

保存用户

            userService.saveUser(new User(null,"John Travolta","jhon","1234", new ArrayList<>()));
            userService.saveUser(new User(null,"Will Smith","will","1234", new ArrayList<>()));
            userService.saveUser(new User(null,"Jim Carry","jim","1234", new ArrayList<>()));
            userService.saveUser(new User(null,"Arnold Schwarzenegger","arnold","1234", new ArrayList<>()));

向用户添加角色

            userService.addRoleToUser("john","ROLE_USER");
            userService.addRoleToUser("will","ROLE_MANAGER");
            userService.addRoleToUser("jim","ROLE_ADMIN");
            userService.addRoleToUser("arnold","ROLE_SUPER_ADMIN");
            userService.addRoleToUser("arnold","ROLE_ADMIN");
            userService.addRoleToUser("arnold","ROLE_USER");
        };

    }

}

Answer 1

原因：java.lang.NullPointerException：无法调用“io.getarrays.userservice.domain.User.getRoles（）”，因为“User”在io.getarrays.userservice.service.UserServiceImpl.addRoleToUser（UserServiceImple.java:36）~[classes/：na]

所以问题出在用户服务的第36行.java。我的猜测：由于该方法的第一个参数：添加罗莱到用户

...可能只是个错别字:“约翰”对“约翰”