ModelMapper中的ClassCastException：无法强制转换EnhancerByModelMapper

Question

Caused by: org.modelmapper.ConfigurationException: ModelMapper configuration errors:

1) Failed to configure mappings

1 error
        at org.modelmapper.internal.Errors.throwConfigurationExceptionIfErrorsExist(Errors.java:241) ~[modelmapper-0.7.4.jar:na]
        at org.modelmapper.internal.ExplicitMappingBuilder.build(ExplicitMappingBuilder.java:207) ~[modelmapper-0.7.4.jar:na]
        at org.modelmapper.internal.TypeMapImpl.addMappings(TypeMapImpl.java:72) ~[modelmapper-0.7.4.jar:na]
        at org.modelmapper.internal.TypeMapStore.getOrCreate(TypeMapStore.java:101) ~[modelmapper-0.7.4.jar:na]
        at org.modelmapper.ModelMapper.addMappings(ModelMapper.java:93) ~[modelmapper-0.7.4.jar:na]
        at configs.AppConfig.modelMapper(AppConfig.java:109) ~[na:na]
        at configs.AppConfig$$EnhancerBySpringCGLIB$$b19a8688.CGLIB$modelMapper$2(<generated>) ~[na:na]
        at configs.AppConfig$$EnhancerBySpringCGLIB$$b19a8688$$FastClassBySpringCGLIB$$1f1c1728.invoke(<generated>) ~[na:na]
        at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) ~[spring-core-4.2.0.RELEASE.jar:4.2.0.RELEASE]
        at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:318) ~[spring-context-4.2.0.RELEASE.jar:4.2.0.RELEASE]
        at configs.AppConfig$$EnhancerBySpringCGLIB$$b19a8688.modelMapper(<generated>) ~[na:na]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_45]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_45]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_45]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_45]
        at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162) ~[spring-beans-4.2.0.RELEASE.jar:4.2.0.RELEASE]
        ... 64 common frames omitted
Caused by: java.lang.ClassCastException: project.entities.User$$EnhancerByModelMapper$$f1b8f0f9 cannot be cast to project.entities.User
        at configs.AppConfig$1.configure(AppConfig.java:106) ~[na:na]
        at org.modelmapper.PropertyMap.configure(PropertyMap.java:383) ~[modelmapper-0.7.4.jar:na]
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_45]
        at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_45]
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_45]
        at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_45]
        at org.modelmapper.internal.ExplicitMappingBuilder.build(ExplicitMappingBuilder.java:195) ~[modelmapper-0.7.4.jar:na]
        ... 78 common frames omitted

@Configuration
public class AppConfig {
    @Bean
    public ModelMapper modelMapper() {
        ModelMapper modelMapper = new ModelMapper();

        // BEGIN: WITHOUT THE FOLLWOING CODE, it works fine
        PropertyMap<CreateUserFormDTO, User> userMap = new PropertyMap<CreateUserFormDTO, User>() {
            @Override
            public void configure() {
                map().setPassword(source.getPassword1());
            }
        };
        modelMapper.addMappings(userMap);
        // END


        return modelMapper;
    }
}

使用简单的Spring@autowire注入访问ModelMapper。User和CreateUserFormDTO类只是POJO。

会有什么问题？

Answer 1

问题正是吉恩所说的。根据Spring-Dev工具：

使用spring-boot-devtools的应用程序在类路径上的文件发生更改时自动重新启动。在IDE中工作时，这可能是一个有用的特性，因为它为代码更改提供了一个非常快速的反馈循环。

当发生代码更改时，ModelMapper库已经由于base ClassLoader而加载到类路径中。根据Spring-Dev工具：

在spring-devtools.properties文件中添加这一行

restart.include.modelmapper=/modelmapper-.*.jar

清理和构建完整的项目。现在，每次发生文件更改时，modelmapper库都将重新加载。

链接：

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