SQL state [null]; error code [0]; Error; nested exception is java.sql.SQLException: Error] with root

### Error querying database.  Cause: java.sql.SQLException: Error
### The error may exist in com/yzc/sem/mapper/TestMapper.java (best guess)
### The error may involve com.yzc.sem.mapper.TestMapper.test
### The error occurred while handling results
### SQL: select * from hr_employee where username='zhuwei'
### Cause: java.sql.SQLException: Error
; uncategorized SQLException; SQL state [null]; error code [0]; Error; nested exception is java.sql.SQLException: Error] with root cause

java.lang.NullPointerException: null
	at com.alibaba.druid.wall.WallFilter.preprocessResultSet(WallFilter.java:1485) ~[druid-1.1.21.jar:1.1.21]
	at com.alibaba.druid.wall.WallFilter.statement_getResultSet(WallFilter.java:720) ~[druid-1.1.21.jar:1.1.21]
	at com.alibaba.druid.filter.FilterChainImpl.statement_getResultSet(FilterChainImpl.java:3016) ~[druid-1.1.21.jar:1.1.21]
	at com.alibaba.druid.wall.WallFilter.statement_getResultSet(WallFilter.java:719) ~[druid-1.1.21.jar:1.1.21]
	at com.alibaba.druid.filter.FilterChainImpl.statement_getResultSet(FilterChainImpl.java:3016) ~[druid-1.1.21.jar:1.1.21]
	at com.alibaba.druid.proxy.jdbc.StatementProxyImpl.getResultSet(StatementProxyImpl.java:359) ~[druid-1.1.21.jar:1.1.21]
	at com.alibaba.druid.pool.DruidPooledStatement.getResultSet(DruidPooledStatement.java:646) ~[druid-1.1.21.jar:1.1.21]
	at io.shardingsphere.core.jdbc.core.statement.MasterSlavePreparedStatement.getResultSet(MasterSlavePreparedStatement.java:137) ~[sharding-jdbc-3.0.0.M3.jar:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_221]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_221]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_221]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_221]
	at org.apache.ibatis.logging.jdbc.PreparedStatementLogger.invoke(PreparedStatementLogger.java:69) ~[mybatis-3.5.0.jar:3.5.0]
	at com.sun.proxy.$Proxy101.getResultSet(Unknown Source) ~[na:na]
	at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.getFirstResultSet(DefaultResultSetHandler.java:237) ~[mybatis-3.5.0.jar:3.5.0]
	at org.apache.ibatis.executor.resultset.DefaultResultSetHandler.handleResultSets(DefaultResultSetHandler.java:187) ~[mybatis-3.5.0.jar:3.5.0]
	at org.apache.ibatis.executor.statement.PreparedStatementHandler.query(PreparedStatementHandler.java:65) ~[mybatis-3.5.0.jar:3.5.0]
	at org.apache.ibatis.executor.statement.RoutingStatementHandler.query(RoutingStatementHandler.java:79) ~[mybatis-3.5.0.jar:3.5.0]
	at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:63) ~[mybatis-3.5.0.jar:3.5.0]
	at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:324) ~[mybatis-3.5.0.jar:3.5.0]
	at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156) ~[mybatis-3.5.0.jar:3.5.0]
	at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109) ~[mybatis-3.5.0.jar:3.5.0]
	at com.github.pagehelper.PageInterceptor.intercept(PageInterceptor.java:108) ~[pagehelper-5.1.10.jar:na]
	at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:61) ~[mybatis-3.5.0.jar:3.5.0]
	at com.sun.proxy.$Proxy99.query(Unknown Source) ~[na:na]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148) ~[mybatis-3.5.0.jar:3.5.0]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141) ~[mybatis-3.5.0.jar:3.5.0]
	at org.apache.ibatis.session.defaults.DefaultSqlSession.selectOne(DefaultSqlSession.java:77) ~[mybatis-3.5.0.jar:3.5.0]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_221]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_221]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_221]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_221]
	at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:433) ~[mybatis-spring-2.0.0.jar:2.0.0]
	at com.sun.proxy.$Proxy64.selectOne(Unknown Source) ~[na:na]
	at org.mybatis.spring.SqlSessionTemplate.selectOne(SqlSessionTemplate.java:166) ~[mybatis-spring-2.0.0.jar:2.0.0]
	at org.apache.ibatis.binding.MapperMethod.execute(MapperMethod.java:84) ~[mybatis-3.5.0.jar:3.5.0]
	at org.apache.ibatis.binding.MapperProxy.invoke(MapperProxy.java:58) ~[mybatis-3.5.0.jar:3.5.0]
	at com.sun.proxy.$Proxy67.test(Unknown Source) ~[na:na]
	at com.yzc.sem.controller.TestController.testController(TestController.java:17) ~[classes/:na]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_221]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_221]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_221]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_221]
	at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:105) ~[spring-webmvc-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:893) ~[spring-webmvc-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:798) ~[spring-webmvc-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.30.jar:9.0.30]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:94) ~[spring-web-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.1.13.RELEASE.jar:5.1.13.RELEASE]
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) [tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) [tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) [tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) [tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) [tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367) [tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) [tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:860) [tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1598) [tomcat-embed-core-9.0.30.jar:9.0.30]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-9.0.30.jar:9.0.30]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_221]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_221]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-9.0.30.jar:9.0.30]
	at java.lang.Thread.run(Thread.java:748) [na:1.8.0_221]

a lot of people on the Internet report errors, and I did it for strange reasons. I’m using the Sharding-JDBC configuration datasource here.

and then I changed it a little bit, using annotations. Configuration is removed and the solution is

//@Configuration
@EnableConfigurationProperties(ShardingMasterSlaveConfig.class)
@ConditionalOnProperty({"sharding.jdbc.data-sources.ds_master.url", "sharding.jdbc.master-slave-rule.master-data-source-name"})

or configuration, remove custom Enable annotation

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