I am learning spring boot and i have recetly learnt about ModelMapper library.
From Student Class, i am trying to map firstName and lastName into fullName from StudentResponseDTO.
Here is Stduent Object:
@Entity
@Table(name = "students")
@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class Student {
@Id
@GeneratedValue()
private Long id;
private String firstName;
private String lastName;
private String email;
private Integer age;
@ManyToOne
@JoinColumn(name = "school_id")
@JsonBackReference
private School school;
@OneToOne(mappedBy = "student", cascade = CascadeType.ALL)
private StudentProfile studentProfile;
}
And this is StudentResponseDTO:
@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
public class StudentResponseDTO {
private String fullName;
private String email;
}
I have created a modelmapper configuration class as below:
@Configuration
public class ModelMapperConfig {
@Bean
public ModelMapper modelMapper() {
ModelMapper modelMapper = new ModelMapper();
// Custom Mappings
modelMapper.createTypeMap(StudentDTO.class, Student.class).addMapping(StudentDTO::getSchoolId, (dest, value) -> dest.getSchool().setId((Long) value));
modelMapper.createTypeMap(Student.class, StudentResponseDTO.class).addMapping(src -> src.getFirstName() + " " + src.getLastName(), StudentResponseDTO::setFullName);
return modelMapper;
}
}
In my controller method, i use the mapper as follows:
@RequestMapping("api/v1/students")
@RestController
@RequiredArgsConstructor
public class StudentController {
private final StudentRepository repository;
private final ModelMapper modelMapper;
@GetMapping
List<StudentResponseDTO> getAllStudent() {
List<Student> studentsList = repository.findAll();
List<StudentResponseDTO> response = studentsList.stream().map(student -> modelMapper.map(student, StudentResponseDTO.class)).toList();
return response;
}
}
I get this error when i hit the endpoint
2024-03-14T10:47:19.460+03:00 ERROR 16452 --- [nio-8080-exec-2] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed: org.modelmapper.MappingException: ModelMapper mapping errors:
1) Error mapping com.example.Spring.Boot.tutorial.model.entities.Student to com.example.Spring.Boot.tutorial.model.dto.StudentResponseDTO
1 error] with root cause
java.lang.IllegalArgumentException: object is not an instance of declaring class
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.checkReceiver(DirectMethodHandleAccessor.java:197) ~[na:na]
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:99) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
at org.modelmapper.internal.PropertyInfoImpl$MethodAccessor.getValue(PropertyInfoImpl.java:99) ~[modelmapper-3.2.0.jar:na]
at org.modelmapper.internal.MappingEngineImpl.resolveSourceValue(MappingEngineImpl.java:197) ~[modelmapper-3.2.0.jar:na]
at org.modelmapper.internal.MappingEngineImpl.propertyMap(MappingEngineImpl.java:170) ~[modelmapper-3.2.0.jar:na]
at org.modelmapper.internal.MappingEngineImpl.typeMap(MappingEngineImpl.java:151) ~[modelmapper-3.2.0.jar:na]
at org.modelmapper.internal.MappingEngineImpl.map(MappingEngineImpl.java:105) ~[modelmapper-3.2.0.jar:na]
at org.modelmapper.internal.MappingEngineImpl.map(MappingEngineImpl.java:71) ~[modelmapper-3.2.0.jar:na]
at org.modelmapper.ModelMapper.mapInternal(ModelMapper.java:589) ~[modelmapper-3.2.0.jar:na]
at org.modelmapper.ModelMapper.map(ModelMapper.java:422) ~[modelmapper-3.2.0.jar:na]
at com.example.Spring.Boot.tutorial.controller.StudentController.lambda$getAllStudent$1(StudentController.java:43) ~[classes/:na]
at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:197) ~[na:na]
at java.base/java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1708) ~[na:na]
at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:509) ~[na:na]
at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:499) ~[na:na]
at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:575) ~[na:na]
at java.base/java.util.stream.AbstractPipeline.evaluateToArrayNode(AbstractPipeline.java:260) ~[na:na]
at java.base/java.util.stream.ReferencePipeline.toArray(ReferencePipeline.java:616) ~[na:na]
at java.base/java.util.stream.ReferencePipeline.toArray(ReferencePipeline.java:622) ~[na:na]
at java.base/java.util.stream.ReferencePipeline.toList(ReferencePipeline.java:627) ~[na:na]
at com.example.Spring.Boot.tutorial.controller.StudentController.getAllStudent(StudentController.java:43) ~[classes/:na]
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:580) ~[na:na]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:259) ~[spring-web-6.1.4.jar:6.1.4]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:192) ~[spring-web-6.1.4.jar:6.1.4]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:118) ~[spring-webmvc-6.1.4.jar:6.1.4]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:920) ~[spring-webmvc-6.1.4.jar:6.1.4]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:830) ~[spring-webmvc-6.1.4.jar:6.1.4]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-6.1.4.jar:6.1.4]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1089) ~[spring-webmvc-6.1.4.jar:6.1.4]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:979) ~[spring-webmvc-6.1.4.jar:6.1.4]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1014) ~[spring-webmvc-6.1.4.jar:6.1.4]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:903) ~[spring-webmvc-6.1.4.jar:6.1.4]
at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:564) ~[tomcat-embed-core-10.1.19.jar:6.0]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:885) ~[spring-webmvc-6.1.4.jar:6.1.4]
at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:658) ~[tomcat-embed-core-10.1.19.jar:6.0]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:205) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51) ~[tomcat-embed-websocket-10.1.19.jar:10.1.19]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-6.1.4.jar:6.1.4]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.1.4.jar:6.1.4]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-6.1.4.jar:6.1.4]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.1.4.jar:6.1.4]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-6.1.4.jar:6.1.4]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.1.4.jar:6.1.4]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:167) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:482) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:115) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:344) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:391) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:896) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1744) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:63) ~[tomcat-embed-core-10.1.19.jar:10.1.19]
at java.base/java.lang.Thread.run(Thread.java:1583) ~[na:na]