方便更快捷的说明问题，可以按需填写（可删除）
使用环境：
依赖：
org.apache.shardingsphere
shardingsphere-jdbc-core-spring-boot-starter
5.2.1
yaml配置：
spring:
shardingsphere:
enabled: true
# 是否开启
datasource:
names: ds0
ds0:
type: com.alibaba.druid.pool.DruidDataSource
driverClassName: com.mysql.cj.jdbc.Driver
username: root
password: root
url: jdbc:mysql://mysql-server:3307/emwd?useSSL=false&serverTimezone=Asia/Shanghai&characterEncoding=utf-8&autoReconnect=true
# 分片的配置
rules:
sharding:
default-data-source-name: ds0
props:
#是否输出sql
sql-show: true
binding-tables[0]: P_USER
# 表的分片策略
tables:
# 逻辑表的名称
P_USER: # 水平分表
actual-data-nodes: ds0.P_USER,ds0.$->{com.yfhx.modules.sharding.ShardingAlgorithmTool.getActualDataNodes(“P_USER”)} # 分库分表分表表达式
table-strategy:
standard:
# 配置分片字段
sharding-column: create_date
# 分片算法名字
sharding-algorithm-name: create_Date
sharding-algorithms: # 分片算法配置
create_Date:
type: CLASS_BASED
props:
strategy: STANDARD
algorithmClassName: com.yfhx.modules.sharding.DateShardingAlgorithm
场景、问题：
项目启动时报错：
Caused by: java.lang.NullPointerException: Properties strategy can not be null when uses class based sharding strategy.
at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:864)
at org.apache.shardingsphere.sharding.algorithm.sharding.classbased.ClassBasedShardingAlgorithm.getStrategy(ClassBasedShardingAlgorithm.java:66)
at org.apache.shardingsphere.sharding.algorithm.sharding.classbased.ClassBasedShardingAlgorithm.init(ClassBasedShardingAlgorithm.java:59)
at org.apache.shardingsphere.infra.util.spi.type.typed.TypedSPIRegistry.findRegisteredService(TypedSPIRegistry.java:66)
at org.apache.shardingsphere.infra.util.spi.type.typed.TypedSPIRegistry.getRegisteredService(TypedSPIRegistry.java:113)
已进行操作：
ClassBasedShardingAlgorithm中getStrategy方法进入两次，第一次正常，第二次为空