找不到請求的操作的編解碼器：[duration <-> java.time.Duration]

Question

有下表

  "CREATE TABLE IF NOT EXISTS user_preferences (" +
                        "    user_id text," +
                        "    my_duration duration," +
                        "    last_modified timestamp," +
                        "    primary key((id))" +
                        ");";

嘗試保留以下模型時

import com.datastax.driver.mapping.annotations.Column;
import com.datastax.driver.mapping.annotations.PartitionKey;
import com.datastax.driver.mapping.annotations.Table;
import java.time.Duration;

@Table(name = "user_preferences")
public class UserPreferences {

    @PartitionKey
    @Column(name = "user_id")
    private String userId;

    @Column(name = "my_duration")
    private Duration myDuration;

    @Column(name = "last_modified")
    private Date lastModified;
}

我得到此編解碼器未找到異常。

com.datastax.driver.core.exceptions.CodecNotFoundException: Codec not found for requested operation: [duration <-> java.time.Duration]
    at com.datastax.driver.core.exceptions.CodecNotFoundException.copy(CodecNotFoundException.java:57) ~[cassandra-driver-core-3.6.0.jar:na]
    at com.datastax.driver.core.exceptions.CodecNotFoundException.copy(CodecNotFoundException.java:25) ~[cassandra-driver-core-3.6.0.jar:na]
    at com.datastax.driver.mapping.DriverThrowables.propagateCause(DriverThrowables.java:39) ~[cassandra-driver-mapping-3.6.0.jar:na]
    at com.datastax.driver.mapping.Mapper.save(Mapper.java:356) ~[cassandra-driver-mapping-3.6.0.jar:na]

注意：讀取工作正常，可能是因為尚未填充表格。

Datastax-core 3.3.2支持java.time.Duration嗎？

---

Answer 1

注釋中的補充：默認編解碼器返回com.datastax.driver.core.Duration！ C *持續時間與java.time.Duration不兼容。 因此，您應該在代碼中使用驅動程序Duration類型，或者提供自己的編解碼器。

這個特定問題的答案錯誤，但是如果您想實施自己的編解碼器仍然很有用，則必須以這種方式進行注冊。

對於其他java.time類，您需要使用/注冊額外的jdk8編解碼器： https ://docs.datastax.com/en/developer/java-driver/3.1/manual/custom_codecs/extras/

import com.datastax.driver.extras.codecs.jdk8.InstantCodec;
import java.time.Instant;

cluster.getConfiguration().getCodecRegistry()
    .register(InstantCodec.instance);

或者如果您無權訪問群集對象

com.datastax.driver.core.CodecRegistry.DEFAULT_INSTANCE.register(InstantCodec.instance);