尝试定义自定义 PropertyMap 时出现 NullPointerException
NullPointerException when trying to define a custom PropertyMap
我按以下方式使用 ModelMapper :
我有一些转换器 class 是 Spring 组件，它们注册自定义 ModelMapper 映射
@Component
public class FooConverter {
@Autowired
private ModelMapper modelMapper;
public static final PropertyMap<Foo, FooModel> FOO_TO_FOO_MODEL_MAP = new PropertyMap<Foo, FooModel>() {
@Override
protected void configure() {
map().setTimeZone(source.getTimeZone().getID());
}
};
@PostConstruct
public void init() {
modelMapper.addMappings(FOO_TO_FOO_MODEL_MAP);
}
}
但是当 Spring 启动时出现以下错误，因为配置函数被调用并且源为空。
这应该如何运作？
我是不是用错了？
1 error
at org.modelmapper.internal.Errors.throwConfigurationExceptionIfErrorsExist(Errors.java:241)
at org.modelmapper.internal.ExplicitMappingBuilder.build(ExplicitMappingBuilder.java:244)
at org.modelmapper.internal.ExplicitMappingBuilder.build(ExplicitMappingBuilder.java:96)
at org.modelmapper.internal.TypeMapImpl.addMappings(TypeMapImpl.java:92)
at org.modelmapper.internal.TypeMapStore.getOrCreate(TypeMapStore.java:124)
at org.modelmapper.ModelMapper.addMappings(ModelMapper.java:113)
at com.agilitypr.neptune.account.api.v1.controllers.PreferenceController.getUserAccountPreferences(PreferenceController.java:63)
at com.agilitypr.neptune.account.api.v1.controllers.PreferenceController$$FastClassBySpringCGLIB$59fcbb.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:746)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:88)
at com.agilitypr.neptune.account.api.v1.filters.AuthorizationFilter.doAuthorize(AuthorizationFilter.java:52)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:644)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:633)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:70)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:174)
at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:88)
at com.agilitypr.neptune.account.api.v1.filters.AuthenticationFilter.doAuthenticate(AuthenticationFilter.java:48)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:644)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:633)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:70)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:174)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:688)
at com.agilitypr.neptune.account.api.v1.controllers.PreferenceController$$EnhancerBySpringCGLIB$$a4d3aeda.getUserAccountPreferences(<generated>)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:865)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1655)
at org.eclipse.jetty.websocket.server.WebSocketUpgradeFilter.doFilter(WebSocketUpgradeFilter.java:215)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:533)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1595)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1317)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:473)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1564)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1219)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.Server.handle(Server.java:531)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:352)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:260)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:281)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:102)
at org.eclipse.jetty.io.ChannelEndPoint.run(ChannelEndPoint.java:118)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:762)
at org.eclipse.jetty.util.thread.QueuedThreadPool.run(QueuedThreadPool.java:680)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NullPointerException
at org.modelmapper.internal.ExplicitMappingBuilder$ExplicitMappingInterceptor.access[=11=]0(ExplicitMappingBuilder.java:304)
at org.modelmapper.internal.ExplicitMappingBuilder.createAccessorProxies(ExplicitMappingBuilder.java:287)
at org.modelmapper.internal.ExplicitMappingBuilder.createProxies(ExplicitMappingBuilder.java:277)
at org.modelmapper.internal.ExplicitMappingBuilder.visitPropertyMap(ExplicitMappingBuilder.java:266)
at org.modelmapper.PropertyMap.configure(PropertyMap.java:386)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.modelmapper.internal.ExplicitMappingBuilder.build(ExplicitMappingBuilder.java:227)
... 90 more
bean 是这样声明的，Foo 和 FooModel 不是最终的
@Configuration
public class FooConfiguration {
@Bean
public ModelMapper modelMapper() {
return new ModelMapper();
}
}
重要编辑
实际上，即使我在 main class 中的函数中显式创建映射，我也会得到相同的 NullPointerException。
public class main {
public static void main(String[] args) {
ModelMapper mapper = new ModelMapper();
final PropertyMap<Foo, FooModel> FOO_TO_FOO_MODEL_MAP = new PropertyMap<Foo, FooModel>() {
@Override
protected void configure() {
map().setTimeZone(source.getTimeZone().getID());
}
};
mapper.addMappings(FOO_TO_FOO_MODEL_MAP );
}
}
怎么了？
我正在按照他们 documentation 中的示例进行操作。
编辑
深度映射正在使用这些
public class InnerFoo {
private int prop3;
public int getProp3() {
return prop3;
}
public void setProp3(int prop3) {
this.prop3 = prop3;
}
}
public class Foo {
private InnerFoo innerFoo;
public InnerFoo getInnerFoo() {
return innerFoo;
}
public void setInnerFoo(InnerFoo innerFoo) {
this.innerFoo = innerFoo;
}
}
public class FooModel {
private int prop2;
public int getProp2() {
return prop2;
}
public void setProp2(int prop2) {
this.prop2 = prop2;
}
}
问题只出在 TimeZone 对象上，所以我必须使用转换器，这并不理想。
map().setTimeZone(source.getTimeZone().getID());
public class Foo {
private TimeZone timeZone;
//Setters//Getters
}
public class FooModel {
private String timeZoneId;
//Setters//Getters
}
使用构造函数自动装配
喜欢
public FooConverter(ModelMapper modelMapper){
this.modelMapper = modelMapper;
}
还要确保您的 ModelMapper bean 已在您的 spring 配置 class 中定义，如下所示：
@Bean
public ModelMapper modelMapper() {
return new ModelMapper();
}
我认为这最终是由于 ModelMapper 在配置映射器时无法实例化 TimeZone 个对象（也不 LocalDateTime 等）。
其实你不需要配置任何东西。
ModelMapper mapper = new ModelMapper();
Foo foo = new Foo();
foo.setTimeZone(TimeZone.getDefault());
FooModel model = mapper.map(foo, FooModel.class);
System.out.println(model.getTimeZoneId()); // "Europe/Berlin" here
这对我有用。 ModelMapper 发现你想映射 TimeZone 的 属性 ID 到 FooModel 的 属性 timeZoneId.
尽管如此，以防万一您想手动执行此操作：
快速查看文档，我找到了 converters 的概念。
使用将 TimeZone 转换为 String 的 Converter 你可以这样做：
ModelMapper mapper = new ModelMapper();
TypeMap<Foo, FooModel> typeMap = mapper.createTypeMap(Foo.class, FooModel.class);
Converter<TimeZone, String> tzConverter = ctx -> ctx.getSource().getID() + "!!!";
typeMap.addMappings(map -> {
map.using(tzConverter).map(Foo::getTimeZone, FooModel::setTimeZoneId);
});
Foo foo = new Foo();
foo.setTimeZone(TimeZone.getDefault());
FooModel model = mapper.map(foo, FooModel.class);
System.out.println(model.getTimeZoneId()); // "Europe/Berlin!!!" here
对于遇到相同问题的任何人：我的问题是我将 PropertyMap 与匿名实现一起使用，就像 spring 配置中建议的文档一样。这在 ExplicitMappingBuilder 中搞砸了。我现在有以下内容：
@Configuration
public class ApplicationConfig {
@Bean
public ModelMapper modelMapper() {
ModelMapper modelMapper = new ModelMapper();
modelMapper.addMappings(new UserPropertyMap());
return modelMapper;
}
}
我的 UserPropertyMap 如下所示：
public class UserPropertyMap extends PropertyMap<UserRepresentation, UserDTO> {
@Override
protected void configure() {
map().setUserName(source.getUsername());
}
}
这在 Spring Boot 2 中非常有效。
我按以下方式使用 ModelMapper :
我有一些转换器 class 是 Spring 组件，它们注册自定义 ModelMapper 映射
@Component
public class FooConverter {
@Autowired
private ModelMapper modelMapper;
public static final PropertyMap<Foo, FooModel> FOO_TO_FOO_MODEL_MAP = new PropertyMap<Foo, FooModel>() {
@Override
protected void configure() {
map().setTimeZone(source.getTimeZone().getID());
}
};
@PostConstruct
public void init() {
modelMapper.addMappings(FOO_TO_FOO_MODEL_MAP);
}
}
但是当 Spring 启动时出现以下错误，因为配置函数被调用并且源为空。
这应该如何运作？
我是不是用错了？
1 error
at org.modelmapper.internal.Errors.throwConfigurationExceptionIfErrorsExist(Errors.java:241)
at org.modelmapper.internal.ExplicitMappingBuilder.build(ExplicitMappingBuilder.java:244)
at org.modelmapper.internal.ExplicitMappingBuilder.build(ExplicitMappingBuilder.java:96)
at org.modelmapper.internal.TypeMapImpl.addMappings(TypeMapImpl.java:92)
at org.modelmapper.internal.TypeMapStore.getOrCreate(TypeMapStore.java:124)
at org.modelmapper.ModelMapper.addMappings(ModelMapper.java:113)
at com.agilitypr.neptune.account.api.v1.controllers.PreferenceController.getUserAccountPreferences(PreferenceController.java:63)
at com.agilitypr.neptune.account.api.v1.controllers.PreferenceController$$FastClassBySpringCGLIB$59fcbb.invoke(<generated>)
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:746)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163)
at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:88)
at com.agilitypr.neptune.account.api.v1.filters.AuthorizationFilter.doAuthorize(AuthorizationFilter.java:52)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:644)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:633)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:70)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:174)
at org.springframework.aop.aspectj.MethodInvocationProceedingJoinPoint.proceed(MethodInvocationProceedingJoinPoint.java:88)
at com.agilitypr.neptune.account.api.v1.filters.AuthenticationFilter.doAuthenticate(AuthenticationFilter.java:48)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethodWithGivenArgs(AbstractAspectJAdvice.java:644)
at org.springframework.aop.aspectj.AbstractAspectJAdvice.invokeAdviceMethod(AbstractAspectJAdvice.java:633)
at org.springframework.aop.aspectj.AspectJAroundAdvice.invoke(AspectJAroundAdvice.java:70)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:174)
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:688)
at com.agilitypr.neptune.account.api.v1.controllers.PreferenceController$$EnhancerBySpringCGLIB$$a4d3aeda.getUserAccountPreferences(<generated>)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:865)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1655)
at org.eclipse.jetty.websocket.server.WebSocketUpgradeFilter.doFilter(WebSocketUpgradeFilter.java:215)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1642)
at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:533)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:146)
at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:548)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:257)
at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1595)
at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:255)
at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1317)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:203)
at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:473)
at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1564)
at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:201)
at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1219)
at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:144)
at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:132)
at org.eclipse.jetty.server.Server.handle(Server.java:531)
at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:352)
at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:260)
at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:281)
at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:102)
at org.eclipse.jetty.io.ChannelEndPoint.run(ChannelEndPoint.java:118)
at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:762)
at org.eclipse.jetty.util.thread.QueuedThreadPool.run(QueuedThreadPool.java:680)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.NullPointerException
at org.modelmapper.internal.ExplicitMappingBuilder$ExplicitMappingInterceptor.access[=11=]0(ExplicitMappingBuilder.java:304)
at org.modelmapper.internal.ExplicitMappingBuilder.createAccessorProxies(ExplicitMappingBuilder.java:287)
at org.modelmapper.internal.ExplicitMappingBuilder.createProxies(ExplicitMappingBuilder.java:277)
at org.modelmapper.internal.ExplicitMappingBuilder.visitPropertyMap(ExplicitMappingBuilder.java:266)
at org.modelmapper.PropertyMap.configure(PropertyMap.java:386)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.modelmapper.internal.ExplicitMappingBuilder.build(ExplicitMappingBuilder.java:227)
... 90 more
bean 是这样声明的，Foo 和 FooModel 不是最终的
@Configuration
public class FooConfiguration {
@Bean
public ModelMapper modelMapper() {
return new ModelMapper();
}
}
重要编辑
实际上，即使我在 main class 中的函数中显式创建映射，我也会得到相同的 NullPointerException。
public class main {
public static void main(String[] args) {
ModelMapper mapper = new ModelMapper();
final PropertyMap<Foo, FooModel> FOO_TO_FOO_MODEL_MAP = new PropertyMap<Foo, FooModel>() {
@Override
protected void configure() {
map().setTimeZone(source.getTimeZone().getID());
}
};
mapper.addMappings(FOO_TO_FOO_MODEL_MAP );
}
}
怎么了？
我正在按照他们 documentation 中的示例进行操作。
编辑
深度映射正在使用这些
public class InnerFoo {
private int prop3;
public int getProp3() {
return prop3;
}
public void setProp3(int prop3) {
this.prop3 = prop3;
}
}
public class Foo {
private InnerFoo innerFoo;
public InnerFoo getInnerFoo() {
return innerFoo;
}
public void setInnerFoo(InnerFoo innerFoo) {
this.innerFoo = innerFoo;
}
}
public class FooModel {
private int prop2;
public int getProp2() {
return prop2;
}
public void setProp2(int prop2) {
this.prop2 = prop2;
}
}
问题只出在 TimeZone 对象上，所以我必须使用转换器，这并不理想。
map().setTimeZone(source.getTimeZone().getID());
public class Foo {
private TimeZone timeZone;
//Setters//Getters
}
public class FooModel {
private String timeZoneId;
//Setters//Getters
}
使用构造函数自动装配 喜欢
public FooConverter(ModelMapper modelMapper){
this.modelMapper = modelMapper;
}
还要确保您的 ModelMapper bean 已在您的 spring 配置 class 中定义，如下所示：
@Bean
public ModelMapper modelMapper() {
return new ModelMapper();
}
我认为这最终是由于 ModelMapper 在配置映射器时无法实例化 TimeZone 个对象（也不 LocalDateTime 等）。
其实你不需要配置任何东西。
ModelMapper mapper = new ModelMapper();
Foo foo = new Foo();
foo.setTimeZone(TimeZone.getDefault());
FooModel model = mapper.map(foo, FooModel.class);
System.out.println(model.getTimeZoneId()); // "Europe/Berlin" here
这对我有用。 ModelMapper 发现你想映射 TimeZone 的 属性 ID 到 FooModel 的 属性 timeZoneId.
尽管如此，以防万一您想手动执行此操作：
快速查看文档，我找到了 converters 的概念。
使用将 TimeZone 转换为 String 的 Converter 你可以这样做：
ModelMapper mapper = new ModelMapper();
TypeMap<Foo, FooModel> typeMap = mapper.createTypeMap(Foo.class, FooModel.class);
Converter<TimeZone, String> tzConverter = ctx -> ctx.getSource().getID() + "!!!";
typeMap.addMappings(map -> {
map.using(tzConverter).map(Foo::getTimeZone, FooModel::setTimeZoneId);
});
Foo foo = new Foo();
foo.setTimeZone(TimeZone.getDefault());
FooModel model = mapper.map(foo, FooModel.class);
System.out.println(model.getTimeZoneId()); // "Europe/Berlin!!!" here
对于遇到相同问题的任何人：我的问题是我将 PropertyMap 与匿名实现一起使用，就像 spring 配置中建议的文档一样。这在 ExplicitMappingBuilder 中搞砸了。我现在有以下内容：
@Configuration
public class ApplicationConfig {
@Bean
public ModelMapper modelMapper() {
ModelMapper modelMapper = new ModelMapper();
modelMapper.addMappings(new UserPropertyMap());
return modelMapper;
}
}
我的 UserPropertyMap 如下所示：
public class UserPropertyMap extends PropertyMap<UserRepresentation, UserDTO> {
@Override
protected void configure() {
map().setUserName(source.getUsername());
}
}
这在 Spring Boot 2 中非常有效。