Cassandra 异常：在类上找不到@Table 注释
[英]Cassandra Exception : @Table annotation not found on the class
问题描述
I am new to cassandra database.
我是 cassandra 数据库的新手。 I am trying to map a table to a java class.我正在尝试将表映射到 Java 类。
My java class:我的java类：
@Table("user")
public class User implements Serializable
{
@PrimaryKey
@Column(value = "id")
private int id;
@Column(value = "first_name")
private String firstName;
//setters and getters
}
Dao class:道类：
public class UserDaoImpl {
Cluster cluster = Cluster.builder().addContactPoint("127.0.0.1").build();
Session session = cluster.connect("agtr_api");
MappingManager manager = new MappingManager(session);
Mapper<User> mapper = manager.mapper(User.class);
public User getUserById(int id){
User u = mapper.get(id);
return u;
}
}
When i run my application on server, It throws following exception:当我在服务器上运行我的应用程序时，它抛出以下异常：
SEVERE: Servlet.service() for servlet [spring] in context with path [/aggregator-api] threw exception [Request processing failed;
2 个解决方案
解决方案1
1 2017-02-11 18:07:14
You can declare also you keyspace name.您也可以声明您的密钥空间名称。 Try to use the complete syntax as below:尝试使用完整的语法如下：
@Table(keyspace = "yourKeyspace", name = "yourTable")
解决方案2
0 2021-04-29 08:32:31
The "@Annotation" error is misleading as you rightly guess and the exception does not directly tell what is the actual error. “@Annotation”错误具有误导性，因为您猜对了，并且异常并没有直接说明实际错误是什么。 The underlying problem would always be in your Domain/Model class fields/columns definition such as column name missing, miss match etc, always watch out your Domain/Model class.潜在的问题总是在您的域/模型类字段/列定义中，例如列名丢失、不匹配等，请始终注意您的域/模型类。
Besides, If you use Achilles library and @Table annotation from Achilles, you will not get correct error.此外，如果您使用 Achilles 库和 Achilles 的 @Table 注释，您将不会得到正确的错误。 As a workaround you can additionally use @Table annotation from DataStax driver which will try to throw you more details in the exception stack trace.作为一种解决方法，您还可以使用来自 DataStax 驱动程序的 @Table 注释，它会尝试在异常堆栈跟踪中向您抛出更多详细信息。
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