未找到請求操作的編解碼器：[UDT("keyspace".user_product_info) <->model.user.UserProductInfo]

Question

問題 ：

我正在使用DataStax Java Driver 4.9我已經在我的密鑰空間中聲明了一個 UDT user_product_info 並且它使用了嵌套的 UDT......在運行程序時它顯示在執行以下行時找不到編解碼器

**

PreparedStatement preparedUpdateFriendRating = session.prepare("UPDATE friend_rating SET user_product_infos=:userproductinfos WHERE user_id=:userId ;");
preparedUpdateFriendRating.bind(new ArrayList(userProductInfo), id);

**

以下是shema.cql

CREATE TYPE IF NOT exists user_product_info (id text,short_product frozen < short_product>,test set < text >,ratings list< frozen < rating > >);

CREATE TABLE IF NOT exists friend_rating(user_id text,user_product_infos list < frozen < user_product_info >>,PRIMARY KEY (user_id));

CREATE TYPE IF NOT exists short_product (name text,specs SET < text >,img text);

帶有對應的java類

//------------------------------------USER PRODUCT INFO-----------


@SchemaHint(targetElement = UDT)
public class UserProductInfo {

    @CqlName("id")
    private String productId;

    @CqlName("short_product")
    private ShortProduct shortProduct;

    @CqlName("test")
    private Set<String> test;

    @CqlName("ratings")
    private List<Rating> ratings;

    public UserProductInfo() {}

//with getters and setters
}

//---------------------------------------SHORT PRODUCT----------------

@SchemaHint(targetElement = UDT)
public class ShortProduct {
    @CqlName("name")
    private String name;

    @CqlName("specs")
    private Set<String> specs;

    @CqlName("img")
    private String imageUrl;

    public ShortProduct() {}
//with getters and setters
}

//--------------------------------------FRIEND RATING TABLE-------------------

@SchemaHint(targetElement = TABLE)
public class FriendRating {
    @PartitionKey
    @CqlName("user_id")
    private String userId;

    @CqlName("user_product_infos")
    private List<UserProductInfo> userProductInfos;

//with getters and setters
}
'''

具有以下堆棧跟蹤：

com.datastax.oss.driver.api.core.type.codec.CodecNotFoundException: Codec not found for requested operation: [UDT("keyspace".user_product_info) <-> model.user.UserProductInfo]
    at com.datastax.oss.driver.internal.core.type.codec.registry.CachingCodecRegistry.createCodec(CachingCodecRegistry.java:609) ~[java-driver-core-4.6.1.jar:na]
    at com.datastax.oss.driver.internal.core.type.codec.registry.DefaultCodecRegistry$1.load(DefaultCodecRegistry.java:95) ~[java-driver-core-4.6.1.jar:na]
    at com.datastax.oss.driver.internal.core.type.codec.registry.DefaultCodecRegistry$1.load(DefaultCodecRegistry.java:92) ~[java-driver-core-4.6.1.jar:na]
    at com.datastax.oss.driver.shaded.guava.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3527) ~[java-driver-shaded-guava-25.1-jre.jar:na]
    at com.datastax.oss.driver.shaded.guava.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2276) ~[java-driver-shaded-guava-25.1-jre.jar:na]
    at com.datastax.oss.driver.shaded.guava.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2154) ~[java-driver-shaded-guava-25.1-jre.jar:na]
    at com.datastax.oss.driver.shaded.guava.common.cache.LocalCache$Segment.get(LocalCache.java:2044) ~[java-driver-shaded-guava-25.1-jre.jar:na]
    at com.datastax.oss.driver.shaded.guava.common.cache.LocalCache.get(LocalCache.java:3951) ~[java-driver-shaded-guava-25.1-jre.jar:na]
    at com.datastax.oss.driver.shaded.guava.common.cache.LocalCache.getOrLoad(LocalCache.java:3973) ~[java-driver-shaded-guava-25.1-jre.jar:na]
    at com.datastax.oss.driver.shaded.guava.common.cache.LocalCache$LocalLoadingCache.get(LocalCache.java:4957) ~[java-driver-shaded-guava-25.1-jre.jar:na]
    at com.datastax.oss.driver.shaded.guava.common.cache.LocalCache$LocalLoadingCache.getUnchecked(LocalCache.java:4963) ~[java-driver-shaded-guava-25.1-jre.jar:na]
    at com.datastax.oss.driver.internal.core.type.codec.registry.DefaultCodecRegistry.getCachedCodec(DefaultCodecRegistry.java:117) ~[java-driver-core-4.6.1.jar:na]
    at com.datastax.oss.driver.internal.core.type.codec.registry.CachingCodecRegistry.codecFor(CachingCodecRegistry.java:196) ~[java-driver-core-4.6.1.jar:na]
    at com.datastax.oss.driver.internal.core.type.codec.registry.CachingCodecRegistry.createCodec(CachingCodecRegistry.java:567) ~[java-driver-core-4.6.1.jar:na]
    at com.datastax.oss.driver.internal.core.type.codec.registry.DefaultCodecRegistry$1.load(DefaultCodecRegistry.java:95) ~[java-driver-core-4.6.1.jar:na]
    at com.datastax.oss.driver.internal.core.type.codec.registry.DefaultCodecRegistry$1.load(DefaultCodecRegistry.java:92) ~[java-driver-core-4.6.1.jar:na]
    at com.datastax.oss.driver.shaded.guava.common.cache.LocalCache$LoadingValueReference.loadFuture(LocalCache.java:3527) ~[java-driver-shaded-guava-25.1-jre.jar:na]
    at com.datastax.oss.driver.shaded.guava.common.cache.LocalCache$Segment.loadSync(LocalCache.java:2276) ~[java-driver-shaded-guava-25.1-jre.jar:na]
    at com.datastax.oss.driver.shaded.guava.common.cache.LocalCache$Segment.lockedGetOrLoad(LocalCache.java:2154) ~[java-driver-shaded-guava-25.1-jre.jar:na]
    at com.datastax.oss.driver.shaded.guava.common.cache.LocalCache$Segment.get(LocalCache.java:2044) ~[java-driver-shaded-guava-25.1-jre.jar:na]
    at com.datastax.oss.driver.shaded.guava.common.cache.LocalCache.get(LocalCache.java:3951) ~[java-driver-shaded-guava-25.1-jre.jar:na]
    at com.datastax.oss.driver.shaded.guava.common.cache.LocalCache.getOrLoad(LocalCache.java:3973) ~[java-driver-shaded-guava-25.1-jre.jar:na]
    at com.datastax.oss.driver.shaded.guava.common.cache.LocalCache$LocalLoadingCache.get(LocalCache.java:4957) ~[java-driver-shaded-guava-25.1-jre.jar:na]
    at com.datastax.oss.driver.shaded.guava.common.cache.LocalCache$LocalLoadingCache.getUnchecked(LocalCache.java:4963) ~[java-driver-shaded-guava-25.1-jre.jar:na]
    at com.datastax.oss.driver.internal.core.type.codec.registry.DefaultCodecRegistry.getCachedCodec(DefaultCodecRegistry.java:117) ~[java-driver-core-4.6.1.jar:na]
    at com.datastax.oss.driver.internal.core.type.codec.registry.CachingCodecRegistry.codecFor(CachingCodecRegistry.java:258) ~[java-driver-core-4.6.1.jar:na]
    at com.datastax.oss.driver.internal.core.data.ValuesHelper.encodePreparedValues(ValuesHelper.java:112) ~[java-driver-core-4.6.1.jar:na]
    at com.datastax.oss.driver.internal.core.cql.DefaultPreparedStatement.bind(DefaultPreparedStatement.java:159) ~[java-driver-core-4.6.1.jar:na]

Answer 1

您有兩種選擇來解決這個問題：

• 按照文檔中的描述為您的 UDT 實現自定義代碼（我不想從中復制代碼）。 這是必需的，因為您使用的是核心 API ( session.execute )
• 切換到使用對象映射器- 您將直接使用您的對象，加載和保存它們等。您已經開始使用@CqlName注釋您的對象，但它們未被使用，因為您需要設置預處理器來生成基於此注釋的代碼。 （您也不需要對簡單的字段名稱進行注釋，例如， names等。對於更復雜的名稱，您也可能不需要注釋，因為對象映射器具有不同的命名翻譯器，例如駝峰式到蛇式等。 )