UserTypeResolver不能为null

Question

我一直在尝试测试Cassandra UDT的插入，并且一直遇到以下错误：线程“ main”中的异常java.lang.IllegalArgumentException：UserTypeResolver不能为null

在尝试找出自己的方式之后，我尝试完全复制以下方法： 用户定义类型与spring-data-cassandra

但是，我仍然遇到相同的错误。

当我删除UDT并仅插入简单类型时，我能够插入到目标数据库中，因此我知道连接正确。我的配置如下：

@Configuration
@PropertySource(value = { "classpath:cassandra.properties" })
//@EnableCassandraRepositories(basePackages = { "org.spring.cassandra.example.repo" })
public class CassandraConfig {

private static final Logger LOG = LoggerFactory.getLogger(CassandraConfig.class);

@Autowired
private Environment env;

@Bean
public CassandraClusterFactoryBean cluster() {

    CassandraClusterFactoryBean cluster = new CassandraClusterFactoryBean();
    cluster.setContactPoints(env.getProperty("cassandra.contactpoints"));
    cluster.setPort(Integer.parseInt(env.getProperty("cassandra.port")));

    return cluster;
}

@Bean
public CassandraMappingContext mappingContext() {
    BasicCassandraMappingContext mappingContext = new BasicCassandraMappingContext();
    mappingContext.setUserTypeResolver(new SimpleUserTypeResolver(cluster().getObject(), "campaign_management"));
    return mappingContext;
}

@Bean
public CassandraConverter converter() {
    return new MappingCassandraConverter(mappingContext());
}

@Bean
public CassandraSessionFactoryBean session() throws Exception {

    CassandraSessionFactoryBean session = new CassandraSessionFactoryBean();
    session.setCluster(cluster().getObject());
    session.setKeyspaceName(env.getProperty("cassandra.keyspace"));
    session.setConverter(converter());
    session.setSchemaAction(SchemaAction.NONE);

    return session;
}

@Bean
public CassandraOperations cassandraTemplate() throws Exception {
    return new CassandraTemplate(session().getObject());
}
}

我的Address和Employee类与我在上面引用的SO问题中显示的完全相同，而Main主要是：

public class MainClass {

public static void main(String[] args) {

ApplicationContext service = new AnnotationConfigApplicationContext(CassandraConfig.class);

Employee employee = new Employee();
employee.setEmployee_id(UUID.randomUUID());
employee.setEmployee_name("Todd");
Address address = new Address();
address.setAddress_type("Home");
address.setId("ToddId");
employee.setAddress(address);
CassandraOperations operations = service.getBean("cassandraTemplate", CassandraOperations.class);

operations.insert(employee);

System.out.println("Done");
}
}

我在用：

datastax.cassandra.driver.version=3.1.3
spring.data.cassandra.version=1.5.1
spring.data.commons.version=1.13.1
spring.cql.version=1.5.1

上一个SO问题中引用的版本是1.5.0，尽管spring.io将1.5.1列为当前版本，所以我正在使用它，并且没有显示1.5.0。

任何帮助将不胜感激，因为这使我有些发疯。

Answer 1

当您在 cassandra 映射下错过 UserTypeResolver 时，通常会收到此错误，该 UserTypeResolver 本身由 cassandra 转换器使用，本身由 Spring Data Cassandra 模板使用

详细信息：

假设你有一个基本的 Spring MVC 控制器在其他地方启动并运行......

Cassandra 中的 UserDefinedTypes 在 SET 和 MAP 中最有趣，下面的示例就是此类。

具有所有默认值的 Spring Bean 配置示例（Spring XML 应用程序上下文摘录）：

<beans xmlns="http://www.springframework.org/schema/beans"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xmlns:cassandra="http://www.springframework.org/schema/data/cassandra"
   xmlns:context="http://www.springframework.org/schema/context"
   xmlns:task="http://www.springframework.org/schema/task"
   xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
   http://www.springframework.org/schema/data/cassandra http://www.springframework.org/schema/data/cassandra/spring-cassandra.xsd
   http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd">
...
<!-- ===== CASSANDRA ===== -->
<!-- Loads the properties into the Spring Context and uses them to fill in placeholders in bean definitions below -->
<context:property-placeholder location="/WEB-INF/spring/cassandra.properties" />

<!-- REQUIRED: The Cassandra Cluster -->
<cassandra:cluster contact-points="${cassandra.contactpoints}"
    port="${cassandra.port}" username="cassandra" password="cassandra"
    auth-info-provider-ref="authProvider" />

<!-- REQUIRED: The Cassandra Session, built from the Cluster, and attaching to a keyspace -->
<cassandra:session keyspace-name="${cassandra.keyspace}" />

<!-- REQUIRED: The Default Cassandra Mapping Context used by CassandraConverter 
     DO include a userTypeResolver for UDT support -->
<cassandra:mapping entity-base-packages="fr.woobe.model">
    <cassandra:user-type-resolver keyspace-name="${cassandra.keyspace}" />
</cassandra:mapping>

<!-- REQUIRED: The Default Cassandra Converter used by CassandraTemplate -->
<cassandra:converter />

<bean id="authProvider" class="com.datastax.driver.core.PlainTextAuthProvider">
    <constructor-arg index="0" value="myCassandraUser" />
    <constructor-arg index="1" value="somePassword" />
</bean>

<!-- REQUIRED: The Cassandra Template is the building block of all Spring Data Cassandra -->
<cassandra:template id="cassandraTemplate" />
...

然后在 java 中，通常在 Spring MVC 控制器中：

import org.springframework.data.cassandra.core.CassandraOperations;
...
// acquire DB template
CassandraOperations cOps = this.beanFactory.getBean("cassandraTemplate", CassandraOperations.class);
// for instance: load everything
List<MyData> rows = cOps.select("SELECT * FROM mydatatable", MyData.class);
// assuming an entry with index i exists...
Set<Pair> mySetOfPairs = rows.get(i).pairSet;
if (mySetOfPairs!=null)
   for (Pair p : mySetOfPairs) { 
        ... handle p.first and p.second ...
...

使用这种实体映射：

package example.model;
import java.util.Set;
import org.springframework.data.cassandra.core.mapping.CassandraType;
import org.springframework.data.cassandra.core.mapping.PrimaryKey;
import org.springframework.data.cassandra.core.mapping.Table;
import com.datastax.driver.core.DataType.Name;

@Table public class MyData {
   @PrimaryKey 
   public String myKey;
   // some other basic fields...
   public String moreStuff;
   // a SET of user defined 'pair type'
   @CassandraType(type = Name.SET, userTypeName = "pairType")
   public Set<Pair> pairSet;

   // your constructors and other methods here...
}

和用户定义的实体，例如：

package example.model;
import org.springframework.data.cassandra.core.mapping.UserDefinedType;

@UserDefinedType("pairType")
public class Pair {
   public String first;
   public String second;

   public Pair() {
   }
   public Pair(String f, String s) {
    this.first= f;
    this.second= s;
   }
}

全部基于创建的 Cassandra 表：

CREATE TYPE pairType (first text, second text);

CREATE TABLE MyData (
  myKey text,
  moreStuff text,
  pairSet set<frozen<pairType>>,
  PRIMARY KEY (myKey)
  ) ;

INSERT INTO MyData (myKey, moreStuff, pairSet) 
  VALUES ('hello', 'world', { 
                  { first:'one', second:'two' }, 
                  { first:'out', second:'there' } } 
         ) ;

就 Maven 工件或库而言，如果您在 Web MVC Spring 控制器中运行，则确实需要 spring-webmvc，然后是 spring-context-support 和 spring-data-cassandra。DataStax cassandra 驱动程序作为依赖项出现。