Cassandra-Springboot 异常问题总结

        最近在做一个Springboot-Cassandra相关项目，由于本人是新接触Cassandra，所以遇到很多棘手的问题，耗费了大量时间查找资料定位问题等，现将期间遇到的一些棘手问题罗列，以便日后复盘学习。

文中将使用到的表定义

CREATE TYPE cass_stdy.address ( addr text, mail text ); CREATE TABLE cass_stdy.user ( id uuid PRIMARY KEY, addr list<frozen<address>>, age int, birthday timestamp, d_addr frozen<address>, name text, score map<text, text> );

(因工程开发过程中遇到问题，需要频繁重启应用，为了提升定位问题效率，重新新建了一个工程和表空间用于针对性的定位相关问题，故表结构均为测试数据，当然也为信息安全考虑)

1. CQL语法方面有一些小细节需要注意

        CQL语句规范与SQL相似，但是由于Cassandra是分布式key-value存储，所以语法上CQL语句存在很多局限性和不同。

CQL语句详细规范请参照Cassandra官方文档 The Cassandra Query Language (CQL)

1) WHERE 条件中小括号“()”内只能带一个条件(通常情况下最好是不带小括号，但是某些工具拼接的语句会带)

误：

SELECT * FROM user WHERE ( id = cf49db81-7821-40e1-8502-871660c14571 AND name = 'MadMonkey' ) ALLOW FILTERING;

正：

SELECT * FROM user WHERE ( id = cf49db81-7821-40e1-8502-871660c14571 ) AND ( name = 'MadMonkey' ) ALLOW FILTERING;

提示：CQL查询条件若涉及非主键字段查询，必须在末尾带上 ALLOW FILTERING

说明：在拼接CQL时如果用到AbstractSQL类，拼接的WHERE条件语句形式是WHERE (id = ? AND name = ?)，这种情况下多条件的CQL会报错。

2) 字符串类型只能用单引号 ', 不能用双引号 "

误：

SELECT * FROM user WHERE name = "MadMonkey" ALLOW FILTERING;

正：

SELECT * FROM user WHERE name = 'MadMonkey' ALLOW FILTERING;

说明：SQL语句可同时支持单双引号，但是CQL只支持单引号，同样CQL也不支持反引号 `。

3) 用户自定义类型(User-defined-type, UDT)，在INSERT和UPDATE操作时字段名不能是字符串

误：

INSERT INTO user (id, d_addr) VALUES (cf49db81-7821-40e1-8502-871660c14571, {'addr': 'SZ-GD-CN', 'mail': '518000'});

正：

INSERT INTO user (id, d_addr) VALUES (cf49db81-7821-40e1-8502-871660c14571, { addr: 'SZ-GD-CN', mail: '518000'});

说明：由于UDT定义相当于表，所以UDT字段相当于表字段，在INSERT和UPDATE操作时即跟表字段的操作一致，而并不等同于map类型或SQL的JSON类型

4) 值类型强校验，字段类型强制限定了值类型，SQL中纯数字字符串可以转换为数字的情况，在CQL中不存在，UUID类型不能是字符串UUID，数字类型也不能是数字字符串

误：

INSERT INTO user (id, age) VALUES ('cf49db81-7821-40e1-8502-871660c14571', '13');

正：

INSERT INTO user (id, age) VALUES (cf49db81-7821-40e1-8502-871660c14571, 13);

提示：时间类型，必须是字符串，如：正：'2020-01-01'，误：2020-01-01

2. 工程异常

cassandra-driver-core和cassandra-driver-mapping经过spring-data的封装，可以实现与SQL相当的大多数功能，详细使用方式请参考 Spring Data Cassandra官方参考文档

以下列举我最近遇到的一些比较棘手的异常，和简单的解决方案

以下将要用到的是Entity和CQL语句

@Table("user") public class User{ @PrimaryKeyColumn(name = "id", type = PrimaryKeyType.PARTITIONED) private UUID id; @Column("name") private String name; @Column("addr") private List<Address> addresses; @Column("d_addr") private Address def; @UserDefinedType("address") public static class Address { @Column("addr") private String addr; @Column("mail") private String mail; /** getter and setter */ } /** getter and setter */ } UPDATE cass_stdy.user SET addr = addr + ? WHERE id = ? IF name = ?

因业务场景要求，涉及到UDT集合类型的增删改查操作，为了防止并发修改，使用了UPDATE IF语句，启动工程执行UPDATE IF出现如下问题：

1) com.datastax.driver.core.exceptions.CodecNotFoundException: Codec not found for requested operation:

com.datastax.driver.core.exceptions.CodecNotFoundException: Codec not found for requested operation: [ANY <-> com.*****.sbstdy.entity.User$Address] at com.datastax.driver.core.CodecRegistry.notFound(CodecRegistry.java:806) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.CodecRegistry.createCodec(CodecRegistry.java:649) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.CodecRegistry.findCodec(CodecRegistry.java:631) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.CodecRegistry.maybeCreateCodec(CodecRegistry.java:732) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.CodecRegistry.createCodec(CodecRegistry.java:648) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.CodecRegistry.findCodec(CodecRegistry.java:631) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.CodecRegistry.codecFor(CodecRegistry.java:476) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.SimpleStatement.convert(SimpleStatement.java:332) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.SimpleStatement.getValues(SimpleStatement.java:146) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.SessionManager.makeRequestMessage(SessionManager.java:600) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.SessionManager.executeAsync(SessionManager.java:142) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.AbstractSession.execute(AbstractSession.java:58) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.AbstractSession.execute(AbstractSession.java:45) ~[cassandra-driver-core-3.7.2.jar:na]

出现这个异常的问题是缺少类型映射，与MyBatis的TypeHandler一样，Cassandra-mapping需要一个TypeCodec，把UDT类型转换为CassandraType。

TypeCodec是一个接口，默认把Java对象转换为ByteBuffer类型供mapping解析，我们需要写一个实现TypeCodec接口的对象转换器。

import com.datastax.oss.driver.api.core.type.codec.TypeCodec; public class AddressTypeCodec implements TypeCodec<User.Address> { @NonNull @Override public GenericType<User.Address> getJavaType() { return GenericType.of(User.Address.class); } @NonNull @Override public DataType getCqlType() { return DataTypes.TEXT; } @Nullable @Override public ByteBuffer encode(@Nullable User.Address value, @NonNull ProtocolVersion protocolVersion) { return ByteBuffer.wrap(new Gson().toJson(value).getBytes()); } @Nullable @Override public User.Address decode(@Nullable ByteBuffer bytes, @NonNull ProtocolVersion protocolVersion) { return new Gson().fromJson(new String(bytes.array()), User.Address.class); } @NonNull @Override public String format(@Nullable User.Address value) { return new Gson().toJson(value); } @Nullable @Override public User.Address parse(@Nullable String value) { return new Gson().fromJson(value, User.Address.class); } }

这里我把Address映射为text类型（这里映射的目标cqlType是什么类型并不重要），cassandra-driver-core 拼接CQL的时候用到了nio的ByteBuffer，所以编解码方法的入参和返回值为ByteBuffer和JavaType，同时TypeCodec生效需要在Configuration中把codec注册进去。

@Configuration @EnableConfigurationProperties(CassandraProperties.class) @EnableCassandraRepositories public class CassandraConfiguration { @Autowired private CassandraProperties properties; @Bean public CqlSession cqlSession() { List<InetSocketAddress> contactPoints = properties.getContactPoints().stream().map(address -> new InetSocketAddress(address, properties.getPort()) ).collect(Collectors.toList()); return CqlSession.builder() .withAuthCredentials(properties.getUsername(), properties.getPassword()) .withKeyspace(properties.getKeyspaceName()) .addContactPoints(contactPoints) .withLocalDatacenter(properties.getLocalDatacenter()) .addTypeCodecs(new AddressTypeCodec()) .build(); } }

此时运行启动，再次执行，出现如下异常

2) com.datastax.driver.core.exceptions.InvalidQueryException: Not enough bytes to read 0th field addr

com.datastax.driver.core.exceptions.InvalidQueryException: Not enough bytes to read 0th field addr at com.datastax.driver.core.Responses$Error.asException(Responses.java:181) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.DefaultResultSetFuture.onSet(DefaultResultSetFuture.java:215) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.RequestHandler.setFinalResult(RequestHandler.java:236) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.RequestHandler.access$2600(RequestHandler.java:62) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.RequestHandler$SpeculativeExecution.setFinalResult(RequestHandler.java:1005) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.RequestHandler$SpeculativeExecution.onSet(RequestHandler.java:808) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.Connection$Dispatcher.channelRead0(Connection.java:1240) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.Connection$Dispatcher.channelRead0(Connection.java:1158) ~[cassandra-driver-core-3.7.2.jar:na] at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:99) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.handler.timeout.IdleStateHandler.channelRead(IdleStateHandler.java:287) ~[netty-handler-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:102) ~[netty-codec-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.handler.codec.ByteToMessageDecoder.fireChannelRead(ByteToMessageDecoder.java:326) ~[netty-codec-4.1.43.Final.jar:4.1.43.Final] at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:300) ~[netty-codec-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:93) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at com.datastax.driver.core.InboundTrafficMeter.channelRead(InboundTrafficMeter.java:38) ~[cassandra-driver-core-3.7.2.jar:na] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:352) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1422) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:360) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:931) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:163) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:700) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:635) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:552) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:514) ~[netty-transport-4.1.43.Final.jar:4.1.43.Final] at io.netty.util.concurrent.SingleThreadEventExecutor$6.run(SingleThreadEventExecutor.java:1050) ~[netty-common-4.1.43.Final.jar:4.1.43.Final] at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74) ~[netty-common-4.1.43.Final.jar:4.1.43.Final] at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30) ~[netty-common-4.1.43.Final.jar:4.1.43.Final] at java.lang.Thread.run(Thread.java:748) [na:1.8.0_231]

这个问题我在经历了1个月时间的定位，寻遍sof、csdn等各大论坛、Spring-Data-Cassandra、Cassandra官方文档，均无法解决，最终通过跟踪Spring-data-cassandra的源码，对比CrudRepository提供的save方法和@Query代理方法的底层实现逻辑，发现最根本的问题在于，TypeCodec<Address>的encode和decode方法中由对象转换生成的ByteBuffer必须按照固定的格式来生成，而我写的ByteBuffer是直接把对象转换为json字符串，再转换成byte[]再转换成的ByteBuffer，由于cassandra-codec取值的方式并不灵活，因此参照UdtCodec提供的方法源码来写自定义的AddressCodec

public class UdtCodec implements TypeCodec<UdtValue> { private final UserDefinedType cqlType; public UdtCodec(@NonNull UserDefinedType cqlType) { this.cqlType = cqlType; } @NonNull @Override public GenericType<UdtValue> getJavaType() { return GenericType.UDT_VALUE; } @NonNull @Override public DataType getCqlType() { return cqlType; } @Override public boolean accepts(@NonNull Object value) { return value instanceof UdtValue && ((UdtValue) value).getType().equals(cqlType); } @Override public boolean accepts(@NonNull Class<?> javaClass) { return UdtValue.class.equals(javaClass); } @Nullable @Override public ByteBuffer encode(@Nullable UdtValue value, @NonNull ProtocolVersion protocolVersion) { if (value == null) { return null; } if (!value.getType().equals(cqlType)) { throw new IllegalArgumentException( String.format( "Invalid user defined type, expected %s but got %s", cqlType, value.getType())); } // Encoding: each field as a [bytes] value ([bytes] = int length + contents, null is // represented by -1) int toAllocate = 0; int size = cqlType.getFieldTypes().size(); for (int i = 0; i < size; i++) { ByteBuffer field = value.getBytesUnsafe(i); toAllocate += 4 + (field == null ? 0 : field.remaining()); } ByteBuffer result = ByteBuffer.allocate(toAllocate); for (int i = 0; i < value.size(); i++) { ByteBuffer field = value.getBytesUnsafe(i); if (field == null) { result.putInt(-1); } else { result.putInt(field.remaining()); result.put(field.duplicate()); } } return (ByteBuffer) result.flip(); } @Nullable @Override public UdtValue decode(@Nullable ByteBuffer bytes, @NonNull ProtocolVersion protocolVersion) { if (bytes == null) { return null; } // empty byte buffers will result in empty values try { ByteBuffer input = bytes.duplicate(); UdtValue value = cqlType.newValue(); int i = 0; while (input.hasRemaining()) { if (i > cqlType.getFieldTypes().size()) { throw new IllegalArgumentException( String.format( "Too many fields in encoded UDT value, expected %d", cqlType.getFieldTypes().size())); } int elementSize = input.getInt(); ByteBuffer element; if (elementSize < 0) { element = null; } else { element = input.slice(); element.limit(elementSize); input.position(input.position() + elementSize); } value = value.setBytesUnsafe(i, element); i += 1; } return value; } catch (BufferUnderflowException e) { throw new IllegalArgumentException("Not enough bytes to deserialize a UDT value", e); } } @NonNull @Override public String format(@Nullable UdtValue value) { // 此处省略无关代码 } @Nullable @Override public UdtValue parse(@Nullable String value) { // 此处省略无关代码 } } @Nullable @Override public ByteBuffer encode(@Nullable User.Address value, @NonNull ProtocolVersion protocolVersion) { if (value == null) { return null; } int toAllocate = 0; ByteBuffer[] values = new ByteBuffer[2]; ByteBuffer field0 = ByteBuffer.wrap(value.getAddr().getBytes()); toAllocate += 4 + field0.remaining(); values[0] = field0; ByteBuffer field1 = ByteBuffer.wrap(value.getMail().getBytes()); toAllocate += 4 + field1.remaining(); values[1] = field1; ByteBuffer result = ByteBuffer.allocate(toAllocate); for (ByteBuffer field : values) { if (field == null) { result.putInt(-1); } else { result.putInt(field.remaining()); result.put(field.duplicate()); } } return (ByteBuffer) result.flip(); } @Nullable @Override public User.Address decode(@Nullable ByteBuffer bytes, @NonNull ProtocolVersion protocolVersion) { if (bytes == null) { return null; } // empty byte buffers will result in empty values try { ByteBuffer input = bytes.duplicate(); User.Address value = new User.Address(); int i = 0; while (input.hasRemaining()) { int elementSize = input.getInt(); ByteBuffer element; if (elementSize < 0) { element = null; } else { element = input.slice(); element.limit(elementSize); input.position(input.position() + elementSize); } if (element != null) { if (i == 0) value.setAddr(new String(element.array())); else if (i == 1) value.setMail(new String(element.array())); } i += 1; } return value; } catch (BufferUnderflowException e) { throw new IllegalArgumentException("Not enough bytes to deserialize a UDT value", e); } }

此时只是做了一个临时的改动，把Address的addr和mail参数硬性塞进ByteBuffer中，尝试一下是否可用。

cqlsh:cass_stdy> SELECT * FROM user; id | addr | age | birthday | d_addr | name | score --------------------------------------+----------------------------------------------------------------------------------------------------------------------------------------------------------+------+----------+--------+----------+------- f7702276-694a-47e1-92cf-312db4101353 | [{addr: 'SZ GD CN', mail: 'sz@gd.cn'}, {addr: 'GZ GD CN', mail: 'gz@gd.cn'}, {addr: 'SZ GD CN', mail: 'sz@gd.cn'}, {addr: 'GZ GD CN', mail: 'gz@gd.cn'}] | null | null | null | name0000 | null (1 rows) cqlsh:cass_stdy>

查询表结果证实成功。

其实仔细研究可以发现encode和decode方法只是把field值取出来按顺序按规则塞进ByteBuffer中，这样的操作完全可以通过反射实现，而不再需要一个一个硬代码取值。当然这是后话。

另附：另外一种替代方案：

CREATE TABLE cass_stdy.user ( id uuid PRIMARY KEY, addr list<frozen<address>>, age int, d_addr frozen<address>, mx list<frozen<map<text, text>>>, name text )

使用list<frozen<map<text, text>>来替代list<UDT>存储数据，但是为了保证Entity转换过程的流畅度，这里再次引用Codec，将Address类型转换为Cassandra map类型，这里引入common-beanutils包用于对象和Map的互相转换。

import com.datastax.driver.core.TypeCodec; import com.datastax.driver.extras.codecs.MappingCodec; import com.google.common.collect.Maps; import org.apache.commons.beanutils.BeanUtils; import java.util.Map; import java.util.stream.Collectors; public class AddressCodec extends MappingCodec<User.Address, Map<String, String>> { public AddressCodec() { super(TypeCodec.map(TypeCodec.varchar(), TypeCodec.varchar()), User.Address.class); } @Override protected User.Address deserialize(Map<String, String> map) { User.Address addr = new User.Address(); try { BeanUtils.populate(addr, map); } catch (Exception e) { e.printStackTrace(); } return addr; } @Override protected Map<String, String> serialize(User.Address o) { Map<String, String> map = Maps.newHashMap(); try { map.putAll(BeanUtils.describe(o) .entrySet() .stream() // cassandra map不能接收null value .filter(entry -> null != entry.getValue()) .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue))); } catch (Exception e) { e.printStackTrace(); } return map; } }

这里需要注意，Cassandra map类型不能接收null value，会提示： Map values cannot be null

java.lang.NullPointerException: Map values cannot be null at com.datastax.driver.core.TypeCodec$AbstractMapCodec.serialize(TypeCodec.java:2086) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.TypeCodec$AbstractMapCodec.serialize(TypeCodec.java:1952) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.extras.codecs.MappingCodec.serialize(MappingCodec.java:56) ~[cassandra-driver-extras-3.9.0.jar:na] at com.datastax.driver.core.TypeCodec$AbstractCollectionCodec.serialize(TypeCodec.java:1782) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.TypeCodec$AbstractCollectionCodec.serialize(TypeCodec.java:1756) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.SimpleStatement.convert(SimpleStatement.java:333) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.SimpleStatement.getValues(SimpleStatement.java:146) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.SessionManager.makeRequestMessage(SessionManager.java:600) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.SessionManager.executeAsync(SessionManager.java:142) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.AbstractSession.execute(AbstractSession.java:58) ~[cassandra-driver-core-3.7.2.jar:na] at com.datastax.driver.core.AbstractSession.execute(AbstractSession.java:45) ~[cassandra-driver-core-3.7.2.jar:na]

所以必须过滤掉null值的Map.Entry，如果需要修改Cassandra map中的值，只能对list中的map<text, text>进行整个替换，如：

UPDATE user SET mx[0] = {'addr':'SZ GD CN'} WHERE id = cf49db81-7821-40e1-8502-871660c14571;

好了，本文暂时到此为止，接下来我将继续探索发现更多Springboot-Cassandra相关的问题和解决方案，并及时更新，请拭目以待。