使用 spring-data-mongodb 持久化包含对象的对象

Question

下面是Question 13832188的后续问题：

我正在使用spring-data-mongodb 版本1.1.1.RELEASE。如果所有成员变量都是原始类型，我可以保留一个对象，即使 @PersistenceConstructor 参数的名称与使用 @Field 和 @Value 注释的成员变量的名称不完全匹配。

但是，当我尝试持久化包含其他对象的对象时，我得到了 MappingInstantiationException。我的问题：

• 这是spring-data-mongodb 中的错误还是我做错了什么？
• 需要更改哪些内容才能正确持久化包含对象的对象？

.

org.springframework.data.mapping.model.MappingInstantiationException: Could not instantiate bean class [com.recorder.TestRecorder2$ObjectContainer]: Illegal arguments for constructor; nested exception is java.lang.IllegalArgumentException: argument type mismatch
    at org.springframework.data.convert.ReflectionEntityInstantiator.createInstance(ReflectionEntityInstantiator.java:77)
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:229)
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:209)
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:173)
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:169)
    at org.springframework.data.mongodb.core.convert.MappingMongoConverter.read(MappingMongoConverter.java:72)
    at org.springframework.data.mongodb.core.MongoTemplate$ReadDbObjectCallback.doWith(MongoTemplate.java:1820)
    at org.springframework.data.mongodb.core.MongoTemplate.executeFindMultiInternal(MongoTemplate.java:1542)
    at org.springframework.data.mongodb.core.MongoTemplate.findAll(MongoTemplate.java:1064)
    at com.recorder.TestRecorder2.testObjectContainer(RecorderTest2.java:63)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
    at org.junit.runners.BlockJUnit4ClassRunner.runNotIgnored(BlockJUnit4ClassRunner.java:79)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:71)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:49)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:193)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
    at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:236)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.recorder.TestRecorder2$ObjectContainer]: Illegal arguments for constructor; nested exception is java.lang.IllegalArgumentException: argument type mismatch
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:158)
    at org.springframework.data.convert.ReflectionEntityInstantiator.createInstance(ReflectionEntityInstantiator.java:75)
    ... 34 more
Caused by: java.lang.IllegalArgumentException: argument type mismatch
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
    at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:147)
    ... 35 more

我的PrimitiveContainer 和ObjectContainer 课程如下：

@Document
class PrimitiveContainer {

    @Field("property") 
    private final int m_property;

    @PersistenceConstructor
    public PrimitiveContainer(@Value("#root.property") int a_property) {
        m_property = a_property;
    }

    public int property() {
        return m_property;
    }
}

@Document
class ObjectContainer {

    @Field("property") 
    private final PrimitiveContainer m_property;

    @PersistenceConstructor
    public ObjectContainer(@Value("#root.property") PrimitiveContainer a_property) {
        m_property = a_property;
    }

    public PrimitiveContainer property() {
        return m_property;
    }
}

---

**更新：**奇怪的是，将@Field 注释中的字符串更改为“属性”以外的其他内容或完全删除ObjectContainer m_property 的@Field 注释允许spring-data-mongo- db to property 重新实例化我的持久化ObjectContainer 类。我不明白为什么会这样。有人有什么想法吗？

Answer 1

您似乎发现了一个错误。第一个 Spel 表达式求值得到的值是 DBObject，实际上并未转换为参数类型。我已经在本地有一些代码可以解决这个问题。你介意创建一个针对 Spring Data MongoDB 的票证以将此作为错误提交吗？