Orika: java.lang.ClassCastException: java.lang.Object 无法转换为 mapper.Name

Question

我正在 here 部分 数组和列表的映射元素.

中做样本示例 orika 映射器文档

下面是我创建 mapperFacade 并将 Person 对象转换为 PersonDto -

的代码

名称 class 定义 -

    public class Name {
        private String first;
        private String last;
        private String fullName;
        // getters/setters

        public Name() {

        }

        public Name(String first, String last, String fullName) {
            this.first = first;
            this.last = last;
            this.fullName = fullName;
        }

        public String getFirst() {
            return first;
        }

        public void setFirst(String first) {
            this.first = first;
        }

        public String getLast() {
            return last;
        }

        public void setLast(String last) {
            this.last = last;
        }

        public String getFullName() {
            return fullName;
        }

        public void setFullName(String fullName) {
            this.fullName = fullName;
        }
    }

人 class 定义 -

import java.util.List;

public class Person {
 private List<Name> names;
 // getters/setters


 public Person() {
 }

public List<Name> getNames() {
    return names;
}

 public void setNames(List<Name> names) {
    this.names = names;
 }
}

PersonDto class 定义 -

import java.util.List;
import java.util.Map;

public class PersonDto {
    private Map<String, Name> personalNames;
    private String[] firstNames;
    private List<String> lastNames;
    // getters/setters omitted

    public PersonDto() {
    }

    public Map<String, Name> getPersonalNames() {
        return personalNames;
    }

    public void setPersonalNames(Map<String, Name> personalNames) {
        this.personalNames = personalNames;
    }

    public String[] getFirstNames() {
        return firstNames;
    }

    public void setFirstNames(String[] firstNames) {
        this.firstNames = firstNames;
    }

    public List<String> getLastNames() {
        return lastNames;
    }

    public void setLastNames(List<String> lastNames) {
        this.lastNames = lastNames;
    }
}


    Map<String,String> fieldMap = new HashMap<>();
    fieldMap.put("names{fullName}", "personalNames{key}");
    fieldMap.put("names{}", "personalNames{value}");
    MapperFactory mapperFactory = new DefaultMapperFactory.Builder().mapNulls(false).dumpStateOnException(false).build();
    ClassMapBuilder<Person, PersonDto> classBuilder = mapperFactory.classMap(Person.class, PersonDto.class);
    fieldMap.forEach((k,v) -> classBuilder.field(k,v));
    classBuilder.register();
    BoundMapperFacade<Person, PersonDto> delegate = mapperFactory.getMapperFacade(Person.class, PersonDto.class);



    Person person = new Person();
    Name n1 = new Name("raj", "kumar", "raj kumar");
    Name n2 = new Name("senthil", "kumar", "senthil kumar");
    person.setNames(Arrays.asList(n1, n2));
    PersonDto pDto = mapper.map(person);
    System.out.println(pDto);

当我运行此代码时，出现以下错误 -

java.lang.Object cannot be cast to mapper.Name java.lang.ClassCastException: java.lang.Object cannot be cast to mapper.Name at ma.glasnost.orika.generated.Orika_PersonDto_Person_Mapper12572858142441[=18=].mapAtoB(Orika_PersonDto_Person_Mapper12572858142441[=18=].java) at ma.glasnost.orika.impl.mapping.strategy.UseCustomMapperStrategy.map(UseCustomMapperStrategy.java:77) at ma.glasnost.orika.impl.DefaultBoundMapperFacade.map(DefaultBoundMapperFacade.java:137) at ma.glasnost.orika.impl.DefaultBoundMapperFacade.map(DefaultBoundMapperFacade.java:94) at mapper.PersonToPersonDtoMapper.map(PersonToPersonDtoMapper.java:29) at mapper.PersonToPersonDtoMapper.map(PersonToPersonDtoMapper.java:14) at mapper.PersonToPersonDtoMapperTest.test1(PersonToPersonDtoMapperTest.java:29) 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.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:133) at org.testng.internal.TestInvoker.invokeMethod(TestInvoker.java:584) at org.testng.internal.TestInvoker.invokeTestMethod(TestInvoker.java:172) at org.testng.internal.MethodRunner.runInSequence(MethodRunner.java:46) at org.testng.internal.TestInvoker$MethodInvocationAgent.invoke(TestInvoker.java:804) at org.testng.internal.TestInvoker.invokeTestMethods(TestInvoker.java:145) at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:146) at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:128) at java.util.ArrayList.forEach(ArrayList.java:1249) at org.testng.TestRunner.privateRun(TestRunner.java:770) at org.testng.TestRunner.run(TestRunner.java:591) at org.testng.SuiteRunner.runTest(SuiteRunner.java:402) at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:396) at org.testng.SuiteRunner.privateRun(SuiteRunner.java:355) at org.testng.SuiteRunner.run(SuiteRunner.java:304)

我在 github here.

上托管了此代码

我的代码有什么问题？我该如何解决这个问题？

Answer 1

出现此问题是因为 Java 泛型在运行时被删除。 Map.Entry<String, Name>（编译时）变为 Map.Entry<Object, Object>（运行时）。

您可以通过如下调整ClassMapBuilder来解决这个问题：

Map<String, String> fieldMap = new HashMap<>();
fieldMap.put("names{fullName}", "personalNames{key}");
fieldMap.put("names{}", "personalNames{value}");
MapperFactory mapperFactory = new DefaultMapperFactory.Builder().mapNulls(false).dumpStateOnException(false).build();
// Swap Person, PersonDto generic arguments.
ClassMapBuilder<PersonDto, Person> classBuilder = mapperFactory.classMap(PersonDto.class, Person.class);
fieldMap.forEach((k, v) -> classBuilder.field(v, k));
classBuilder.register();
// rest of the code is the same

Orika: java.lang.ClassCastException: java.lang.Object 无法转换为 mapper.Name

Orika: java.lang.ClassCastException: java.lang.Object cannot be cast to mapper.Name

java

orika