HDC调试需求开发（15万预算）,能者速来！>>>
spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/xx?serverTimezone=utc&characterEncoding=utf8&useUnicode=true&useSSL=false
spring.datasource.username=xxx
spring.datasource.password=xxx
spring.datasource.driverClassName=com.mysql.cj.jdbc.Driver
spring.datasource.initialSize=5
spring.datasource.minIdle=5
spring.datasource.maxActive=20
spring.datasource.maxWait=60000
spring.datasource.filters=stat,wall
spring.datasource.timeBetweenEvictionRunsMillis=60000
spring.datasource.minEvictableIdleTimeMillis=300000
spring.datasource.validationQuery=select 'x'
spring.datasource.testWhileIdle=true
spring.datasource.testOnBorrow=false
spring.datasource.testOnReturn=false
spring.datasource.poolPreparedStatements=true
spring.datasource.maxPoolPreparedStatementPerConnectionSize=20
spring.datasource.connectionProperties=druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
spring.druidLoginName=admin
spring.druidPassword=admin

@Bean
public SqlSessionFactoryBean sqlSessionFactory(DruidDataSource datasource){
SqlSessionFactoryBean bean=new SqlSessionFactoryBean();
datasource.setInitialSize(initialSize);
datasource.setMinIdle(minIdle);
datasource.setMaxActive(maxActive);
datasource.setMaxWait(maxWait);
datasource.setTimeBetweenEvictionRunsMillis(timeBetweenEvictionRunsMillis);
datasource.setMinEvictableIdleTimeMillis(minEvictableIdleTimeMillis);
datasource.setValidationQuery(validationQuery);
datasource.setTestWhileIdle(testWhileIdle);
datasource.setTestOnBorrow(testOnBorrow);
datasource.setTestOnReturn(testOnReturn);
datasource.setPoolPreparedStatements(poolPreparedStatements);
datasource.setMaxPoolPreparedStatementPerConnectionSize(maxPoolPreparedStatementPerConnectionSize);
try {
datasource.setFilters(filters);
} catch (SQLException e) {
e.printStackTrace();
}
datasource.setConnectionProperties(connectionProperties);
bean.setDataSource(datasource);
return bean;
}

@Bean
public SqlSessionTemplate sqlSession(SqlSessionFactoryBean sqlSessionFactory){
SqlSessionTemplate bean=null;
try {
bean = new SqlSessionTemplate(sqlSessionFactory.getObject());
} catch (Exception e) {
e.printStackTrace();
}
return bean;
}

报错如下：
[2019-03-16 17:14:38] ERROR org.springframework.boot.SpringApplication - Application run failed
java.util.ConcurrentModificationException: null
at java.util.LinkedHashMap$LinkedHashIterator.nextNode(LinkedHashMap.java:719)
at java.util.LinkedHashMap$LinkedKeyIterator.next(LinkedHashMap.java:742)
at org.springframework.context.support.AbstractApplicationContext.registerListeners(AbstractApplicationContext.java:810)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:543)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:142)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:316)
at net.hb.xuelebaoapp.config.MainApplication.main(MainApplication.java:19)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49)
[2019-03-16 17:14:38] INFO org.apache.catalina.loader.WebappClassLoaderBase - Illegal access: this web application instance has been stopped already. Could not load [com.mysql.jdbc.MySQLConnection]. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
java.lang.IllegalStateException: Illegal access: this web application instance has been stopped already. Could not load [com.mysql.jdbc.MySQLConnection]. The following stack trace is thrown for debugging purposes as well as to attempt to terminate the thread which caused the illegal access.
at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForResourceLoading(WebappClassLoaderBase.java:1363)
at org.apache.catalina.loader.WebappClassLoaderBase.checkStateForClassLoading(WebappClassLoaderBase.java:1351)
at org.apache.catalina.loader.WebappClassLoaderBase.findClass(WebappClassLoaderBase.java:820)
at org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader.findClassIgnoringNotFound(TomcatEmbeddedWebappClassLoader.java:121)
at org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader.doLoadClass(TomcatEmbeddedWebappClassLoader.java:86)
at org.springframework.boot.web.embedded.tomcat.TomcatEmbeddedWebappClassLoader.loadClass(TomcatEmbeddedWebappClassLoader.java:68)
at org.apache.catalina.loader.WebappClassLoaderBase.loadClass(WebappClassLoaderBase.java:1173)
at com.alibaba.druid.util.Utils.loadClass(Utils.java:220)
at com.alibaba.druid.pool.vendor.MySqlValidConnectionChecker.<init>(MySqlValidConnectionChecker.java:50)
at com.alibaba.druid.pool.DruidDataSource.initValidConnectionChecker(DruidDataSource.java:1231)
at com.alibaba.druid.pool.DruidDataSource.init(DruidDataSource.java:885)
at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:1300)
at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:1296)
at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:109)
at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:157)
at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:115)
at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:78)
at org.mybatis.spring.transaction.SpringManagedTransaction.openConnection(SpringManagedTransaction.java:82)
at org.mybatis.spring.transaction.SpringManagedTransaction.getConnection(SpringManagedTransaction.java:68)
at org.apache.ibatis.executor.BaseExecutor.getConnection(BaseExecutor.java:338)
at org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:84)
at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:62)
at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:326)
at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156)
at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109)
at com.github.pagehelper.PageInterceptor.intercept(PageInterceptor.java:108)
at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:61)
at com.sun.proxy.$Proxy96.query(Unknown Source)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141)
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:136)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:433)
at com.sun.proxy.$Proxy93.selectList(Unknown Source)
at org.mybatis.spring.SqlSessionTemplate.selectList(SqlSessionTemplate.java:222)
at net.hb.xuelebaoapp.system.dao.impl.FredaDaoImpl.queryForList(FredaDaoImpl.java:105)
at net.hb.xuelebaoapp.manager.sys.service.impl.ParamServiceImpl.list(ParamServiceImpl.java:41)
at net.hb.xuelebaoapp.system.listener.SystemInitListener$launchSPMonitor.run(SystemInitListener.java:82)
at java.lang.Thread.run(Thread.java:748)
[2019-03-16 17:14:39] INFO com.alibaba.druid.pool.DruidDataSource - {dataSource-1} inited
[2019-03-16 17:14:39] INFO com.alibaba.druid.pool.DruidDataSource - {dataSource-1} closed

通过换mysql驱动包和druid驱动包版本，试了都不行