使用Spring-data-cassandra查询具有复合主键的表

Question

使用CassandraReporitory的findOne（）或findAll（）方法时，我得到以下异常：

Caused by: java.lang.IllegalStateException: property does not have a single column mapping
    at org.springframework.data.cassandra.mapping.BasicCassandraPersistentProperty.getColumnName(BasicCassandraPersistentProperty.java:134)
    at org.springframework.data.cassandra.convert.BasicCassandraRowValueProvider.getPropertyValue(BasicCassandraRowValueProvider.java:64)
    at org.springframework.data.cassandra.convert.BasicCassandraRowValueProvider.getPropertyValue(BasicCassandraRowValueProvider.java:35)
    at org.springframework.data.mapping.model.PersistentEntityParameterValueProvider.getParameterValue(PersistentEntityParameterValueProvider.java:78)
    at org.springframework.data.convert.ReflectionEntityInstantiator.createInstance(ReflectionEntityInstantiator.java:71)
    at org.springframework.data.convert.ClassGeneratingEntityInstantiator.createInstance(ClassGeneratingEntityInstantiator.java:83)
    at org.springframework.data.cassandra.convert.MappingCassandraConverter.readEntityFromRow(MappingCassandraConverter.java:133)
    at org.springframework.data.cassandra.convert.MappingCassandraConverter.readRow(MappingCassandraConverter.java:115)
    at org.springframework.data.cassandra.convert.MappingCassandraConverter.read(MappingCassandraConverter.java:200)
    at org.springframework.data.cassandra.repository.query.AbstractCassandraQuery.getSingleEntity(AbstractCassandraQuery.java:176)
    at org.springframework.data.cassandra.repository.query.AbstractCassandraQuery.execute(AbstractCassandraQuery.java:133)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:454)
    at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:432)

我的课程定义如下：

@PrimaryKeyClass
public class ItemAndLocationKey implements Serializable {

    private static final long serialVersionUID = 1L;

    @PrimaryKeyColumn(name = "itemId", ordinal = 0, type = PrimaryKeyType.PARTITIONED)
    @CassandraType(type = Name.UUID)
    private UUID itemId;
    @PrimaryKeyColumn(name = "locationId", ordinal = 1, type = PrimaryKeyType.CLUSTERED)
    @CassandraType(type = Name.UUID)
    private UUID locationId;

    public ItemAndLocationKey(UUID itemId, UUID locationId) {
        this.itemId = itemId;
        this.locationId = locationId;
    }

    public UUID getItemId() {
        return itemId;
    }

    public void setItemId(UUID itemId) {
        this.itemId = itemId;
    }

    public UUID getLocationId() {
        return locationId;
    }

    public void setLocationId(UUID locationId) {
        this.locationId = locationId;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;

        ItemAndLocationKey that = (ItemAndLocationKey) o;

        if (!itemId.equals(that.itemId)) return false;
        return locationId.equals(that.locationId);
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + itemId.hashCode();
        result = prime * result + locationId.hashCode();
        return result;
    }
}

---

@Table(value = ItemAndLocation.tableName)
public class ItemAndLocation {

    @org.springframework.data.annotation.Transient
    public static final String tableName = "ItemAndLocation";

    @PrimaryKey
    private ItemAndLocationKey itemAndLocationKey;

    public ItemAndLocation(ItemAndLocationKey itemAndLocationKey) {
        this.itemAndLocationKey = itemAndLocationKey;
    }

    public ItemAndLocationKey getItemAndLocationKey() {
        return itemAndLocationKey;
    }

    public void setItemAndLocationKey(ItemAndLocationKey itemAndLocationKey) {
        this.itemAndLocationKey = itemAndLocationKey;
    }
}

---

public interface ItemAndLocationRepository extends TypedIdCassandraRepository<ItemAndLocation, ItemAndLocationKey> {

}

---

本质上发生的事情是，在调用findOne（）或findAll（）期间从Cassandra读取一行后，spring数据cassandra尝试使用ClassGeneratingEntityInstantiator来实例化不知道如何填充复合主键对象的ItemAndLocation对象， ItemAndLocationKey。我无法弄清楚如何提供自定义对象实例化器。当前版本没有示例或文档。

任何帮助都感激不尽。

Answer 1

我有同样的问题，问题出在用@Table注释的类中。

在您的方案中，您必须删除以下类中的重载构造函数：

@Table(value = ItemAndLocation.tableName)
public class ItemAndLocation {

    @org.springframework.data.annotation.Transient
    public static final String tableName = "ItemAndLocation";

    @PrimaryKey
    private ItemAndLocationKey itemAndLocationKey;

    // \\\\\\\\\\\\\\\\\\\\ REMOVE THIS CONSTRUCTOR //////////////////
    // public ItemAndLocation(ItemAndLocationKey itemAndLocationKey) {
    //    this.itemAndLocationKey = itemAndLocationKey;
    // }
    // ////////////////////////////////\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\


    public ItemAndLocationKey getItemAndLocationKey() {
        return itemAndLocationKey;
    }

    public void setItemAndLocationKey(ItemAndLocationKey itemAndLocationKey) {
        this.itemAndLocationKey = itemAndLocationKey;
   }
}

我希望这有帮助 ：）

Answer 2

我在Main实体类和PrimaryKey类中都遇到了同样的问题。为我修复的是提供不带参数的默认构造函数并将所有字段初始化为某个默认值，对于nulls，Object，对于falses，boolean，对于所有其他原始类型，0。

在你的情况下，这将意味着添加：

private ItemAndLocation() {
    this.itemAndLocationKey = null;
}

和

private ItemAndLocationKey() {
    this.itemId = null;
    this.locationId = null;
}

构造函数不需要是public，字段可以是final，框架将通过反射设置值。