当我尝试使用SpEL将User传递给服务方法时，我面临下一个问题，
evaluate expression="commonService.userTest(user)" result="flowScope.user"
spring引发了以下异常：
org.springframework.expression.spel.SpelEvaluationException：EL1004E：（pos 14）：方法调用：方法userTest（com.x.domain.common.User）在com.sun.proxy上找不到。$ Proxy114类型
但是当我传递纯文本而不是User对象时，
evaluate expression="commonService.userTest('Hello')" result="flowScope.user"
没有错误。
@Entity
@Table(name = "users")
@Getter
@Setter
@NoArgsConstructor
@Slf4j
public class User extends BaseEntity implements UserDetails {
@Column(unique = true)
@NotEmpty
private String username;
@Column
@NotEmpty
@Size(min = 5)
private String password;
}
@Service("commonService")
public class CommonServiceImpl implements CommonService {
@Transactional(readOnly = true)
@Override
public User userTest(String name) {
User user = createUser();
user.setUsername(name);
return user;
}
@Transactional(readOnly = true)
@Override
public User userTest(User user) {
return user;
}
}
更新＃2 - 解决方法
删除DevTools依赖项解决了这个问题，但应用此解决方案Spring Boot Dev Tools & Web Flow don't play nice但在spring-devtools.properties下使用以下行创建src/main/resources/META-INF/使其完全没有问题
restart.include.spring=/.*\.jar
为什么我没有链接中提到的这一行：
restart.include.spring=/spring-.*\.jar
因为我得到了这个例外
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'webFlowConfig': Unsatisfied dependency expressed through field 'webMvcConfig'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'webMvcConfig': Unsatisfied dependency expressed through field 'springTemplateEngine'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration$ThymeleafDefaultConfiguration': Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'defaultTemplateResolver' defined in class path resource [org/springframework/boot/autoconfigure/thymeleaf/ThymeleafAutoConfiguration$Thymeleaf3Configuration$DefaultTemplateResolverConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.thymeleaf.spring4.templateresolver.SpringResourceTemplateResolver]: Factory method 'defaultTemplateResolver' threw exception; nested exception is java.lang.LinkageError: loader constraint violation: when resolving method "org.thymeleaf.spring4.templateresolver.SpringResourceTemplateResolver.setApplicationContext(Lorg/springframework/context/ApplicationContext;)V" the class loader (instance of org/springframework/boot/devtools/restart/classloader/RestartClassLoader) of the current class, org/springframework/boot/autoconfigure/thymeleaf/AbstractTemplateResolverConfiguration, and the class loader (instance of sun/misc/Launcher$AppClassLoader) for the method's defining class, org/thymeleaf/spring4/templateresolver/SpringResourceTemplateResolver, have different Class objects for the type org/springframework/context/ApplicationContext used in the signature
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:588) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1264) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:867) ~[spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543) ~[spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:693) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:360) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:303) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1118) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1107) [spring-boot-1.5.6.RELEASE.jar:1.5.6.RELEASE]
at medicallab.MedicallabApplication.main(MedicallabApplication.java:10) [classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_121]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_121]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_121]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_121]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-1.5.6.RELEASE.jar:1.5.6.RELEASE]
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'webMvcConfig': Unsatisfied dependency expressed through field 'springTemplateEngine'; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration$ThymeleafDefaultConfiguration': Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'defaultTemplateResolver' defined in class path resource [org/springframework/boot/autoconfigure/thymeleaf/ThymeleafAutoConfiguration$Thymeleaf3Configuration$DefaultTemplateResolverConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.thymeleaf.spring4.templateresolver.SpringResourceTemplateResolver]: Factory method 'defaultTemplateResolver' threw exception; nested exception is java.lang.LinkageError: loader constraint violation: when resolving method "org.thymeleaf.spring4.templateresolver.SpringResourceTemplateResolver.setApplicationContext(Lorg/springframework/context/ApplicationContext;)V" the class loader (instance of org/springframework/boot/devtools/restart/classloader/RestartClassLoader) of the current class, org/springframework/boot/autoconfigure/thymeleaf/AbstractTemplateResolverConfiguration, and the class loader (instance of sun/misc/Launcher$AppClassLoader) for the method's defining class, org/thymeleaf/spring4/templateresolver/SpringResourceTemplateResolver, have different Class objects for the type org/springframework/context/ApplicationContext used in the signature
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:588) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1264) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:585) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
... 24 common frames omitted
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration$ThymeleafDefaultConfiguration': Unsatisfied dependency expressed through constructor parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'defaultTemplateResolver' defined in class path resource [org/springframework/boot/autoconfigure/thymeleaf/ThymeleafAutoConfiguration$Thymeleaf3Configuration$DefaultTemplateResolverConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.thymeleaf.spring4.templateresolver.SpringResourceTemplateResolver]: Factory method 'defaultTemplateResolver' threw exception; nested exception is java.lang.LinkageError: loader constraint violation: when resolving method "org.thymeleaf.spring4.templateresolver.SpringResourceTemplateResolver.setApplicationContext(Lorg/springframework/context/ApplicationContext;)V" the class loader (instance of org/springframework/boot/devtools/restart/classloader/RestartClassLoader) of the current class, org/springframework/boot/autoconfigure/thymeleaf/AbstractTemplateResolverConfiguration, and the class loader (instance of sun/misc/Launcher$AppClassLoader) for the method's defining class, org/thymeleaf/spring4/templateresolver/SpringResourceTemplateResolver, have different Class objects for the type org/springframework/context/ApplicationContext used in the signature
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:749) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.autowireConstructor(ConstructorResolver.java:189) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireConstructor(AbstractAutowireCapableBeanFactory.java:1193) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1095) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:372) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:585) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
... 37 common frames omitted
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'defaultTemplateResolver' defined in class path resource [org/springframework/boot/autoconfigure/thymeleaf/ThymeleafAutoConfiguration$Thymeleaf3Configuration$DefaultTemplateResolverConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.thymeleaf.spring4.templateresolver.SpringResourceTemplateResolver]: Factory method 'defaultTemplateResolver' threw exception; nested exception is java.lang.LinkageError: loader constraint violation: when resolving method "org.thymeleaf.spring4.templateresolver.SpringResourceTemplateResolver.setApplicationContext(Lorg/springframework/context/ApplicationContext;)V" the class loader (instance of org/springframework/boot/devtools/restart/classloader/RestartClassLoader) of the current class, org/springframework/boot/autoconfigure/thymeleaf/AbstractTemplateResolverConfiguration, and the class loader (instance of sun/misc/Launcher$AppClassLoader) for the method's defining class, org/thymeleaf/spring4/templateresolver/SpringResourceTemplateResolver, have different Class objects for the type org/springframework/context/ApplicationContext used in the signature
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.addCandidateEntry(DefaultListableBeanFactory.java:1316) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.findAutowireCandidates(DefaultListableBeanFactory.java:1282) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveMultipleBeans(DefaultListableBeanFactory.java:1180) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1096) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.resolveAutowiredArgument(ConstructorResolver.java:835) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:741) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
... 59 common frames omitted
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.thymeleaf.spring4.templateresolver.SpringResourceTemplateResolver]: Factory method 'defaultTemplateResolver' threw exception; nested exception is java.lang.LinkageError: loader constraint violation: when resolving method "org.thymeleaf.spring4.templateresolver.SpringResourceTemplateResolver.setApplicationContext(Lorg/springframework/context/ApplicationContext;)V" the class loader (instance of org/springframework/boot/devtools/restart/classloader/RestartClassLoader) of the current class, org/springframework/boot/autoconfigure/thymeleaf/AbstractTemplateResolverConfiguration, and the class loader (instance of sun/misc/Launcher$AppClassLoader) for the method's defining class, org/thymeleaf/spring4/templateresolver/SpringResourceTemplateResolver, have different Class objects for the type org/springframework/context/ApplicationContext used in the signature
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEASE]
... 75 common frames omitted
Caused by: java.lang.LinkageError: loader constraint violation: when resolving method "org.thymeleaf.spring4.templateresolver.SpringResourceTemplateResolver.setApplicationContext(Lorg/springframework/context/ApplicationContext;)V" the class loader (instance of org/springframework/boot/devtools/restart/classloader/RestartClassLoader) of the current class, org/springframework/boot/autoconfigure/thymeleaf/AbstractTemplateResolverConfiguration, and the class loader (instance of sun/misc/Launcher$AppClassLoader) for the method's defining class, org/thymeleaf/spring4/templateresolver/SpringResourceTemplateResolver, have different Class objects for the type org/springframework/context/ApplicationContext used in the signature
at org.springframework.boot.autoconfigure.thymeleaf.AbstractTemplateResolverConfiguration.defaultTemplateResolver(AbstractTemplateResolverConfiguration.java:70) ~[spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE]
at org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration$Thymeleaf3Configuration$DefaultTemplateResolverConfiguration.defaultTemplateResolver(ThymeleafAutoConfiguration.java:140) ~[spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE]
at org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration$Thymeleaf3Configuration$DefaultTemplateResolverConfiguration$$EnhancerBySpringCGLIB$$f2a7a126.CGLIB$defaultTemplateResolver$0(<generated>) ~[spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE]
at org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration$Thymeleaf3Configuration$DefaultTemplateResolverConfiguration$$EnhancerBySpringCGLIB$$f2a7a126$$FastClassBySpringCGLIB$$7a53489b.invoke(<generated>) ~[spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE]
at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) ~[spring-core-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:358) ~[spring-context-4.3.10.RELEASE.jar:4.3.10.RELEASE]
at org.springframework.boot.autoconfigure.thymeleaf.ThymeleafAutoConfiguration$Thymeleaf3Configuration$DefaultTemplateResolverConfiguration$$EnhancerBySpringCGLIB$$f2a7a126.defaultTemplateResolver(<generated>) ~[spring-boot-autoconfigure-1.5.6.RELEASE.jar:1.5.6.RELEASE]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_121]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_121]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_121]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_121]
at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162) ~[spring-beans-4.3.10.RELEASE.jar:4.3.10.RELEA
SE]
... 76 common frames omitted
所以我现在必须包括所有的罐子。希望这可能会对未来的某些人有所帮助，但请参考更新＃1，因为这可能会在将来的Spring DevTools classloader limitations中解决，但导致LiveReload服务器无法运行。
更新＃1
这似乎是一个DevTools问题（Customizing the restart classloader）可能会很快修复Spring DevTools classloader limitations。它是在这个问题Spring Boot Dev Tools & Web Flow don't play nice开始的
原始答案
我有几次同样的问题，我做了一个测试，我发现了一个奇怪的行为。
public class SomeModel implements Serializable {
private static final long serialVersionUID = -7967970066125990593L;
...
}
custom flow action.Java
package app.flow;
public class CustomFlowAction {
// Note here the paramter is of type Object, just to use casting instead of using the object directly to test if I have the correct one
public boolean someAction(Object obj, RequestContext context) {
SomeModel someModel = (SomeModel) obj;
return true
}
public SomeModel prepareSomeModel() {
return new SomeModel();
}
}
（流程示例1）some-flow.xml
这个例子使用的是一个spring bean，它运行正常，someAction方法返回true。
<flow ...>
<view-state id="StateOne" model="someModel">
<transition on="next" to="StateTwo">
<evaluate expression="customFlowAction.someAction(someModel, flowRequestContext)"></evaluate>
</transition>
</view-state>
</flow>
（流程示例2）some-flow.xml
这个例子是从SomeModel创建一个新对象并将其存储在flowScope中，然后在模板中使用它。
<flow ...>
<on-start>
<evaluate expression="submitRequestFlowAction.prepareSomeModel()" result="flowScope.someModel"></evaluate>
</on-start>
<view-state id="StateOne" model="someModel">
<transition on="next" to="StateTwo">
<evaluate expression="customFlowAction.someAction(someModel, flowRequestContext)"></evaluate>
</transition>
</view-state>
</flow>
输出是：
java.lang.ClassCastException: app.flow.SomeModel cannot be cast to app.flow.SomeModel
有些人引导我到可能有另一个类加载器参与该问题，一个人告诉我这个：
请注意，类加载器是类类型的一部分：由类加载器CL1加载的类A与类加载器CL2加载的类A不同，即使实际的A.class可能是同一个文件
希望这对你和其他像我这样麻烦的人有帮助:)
我收到了与从数据库中检索对象相关的错误。为了解决这个问题，我创建了一个服务类，它通过一个事务调用代理对象并解决了它。
@Transactional(readOnly = true)
public User findOneByCustomerPersonalEmail(String email) {
User user = userRepository.findOneByCustomerPersonalEmail(email);
user.getCustomer(); //this line fills the proxied object
return user;
}