ShardingSphere-JDBC 5.0.0-beta使用：数据源拒绝建立连接，来自服务器的消息：“连接太多”

问题分析：I wonder if the jar package is missing.This is a non Maven project.

问题处理：调试发现，问题出在少了蛮多依赖包。由于是非maven项目，有些jar包还可能冲突，版本不能向下兼容等问题。jar包引入或少或冲突，仅供参考，此处仅做记录，避免再次采坑。

如所依赖Guava包冲突，冲突解决可参考：

https://blog.csdn.net/u014698745/article/details/119944988。

##There are several dependencies not added

avatica-core-1.17.0.jar
calcite-core-1.26.0.jar
calcite-linq4j-1.26.0.jar
commons-compiler-3.0.11.jar
ehcache-2.7.5.jar
esri-geometry-api-2.2.0.jar
failureaccess-1.0.1.jar
guava-29.0-jre.jar
janino-3.0.11.jar
json-path-2.4.0.jar
listenablefuture-9999.0-empty-to-avoid-conflict-with-guava.jar

antlr4-runtime-4.7.2.jar
protobuf-java-3.6.1.jar

##Dependency conflict,just use thisshardingsphere-transaction-core-5.0.0-beta.jar

 错误描述：HikariPool循环初始化，导致“java.sql.SQLNonTransientConnectionException: Data source rejected establishment of connection, message from server: "Too many connections"，即数据源拒绝建立连接，来自服务器的消息：“连接太多”

错误异常：

[com.zaxxer.hikari.HikariDataSource]HikariPool-115 - Starting...
[com.zaxxer.hikari.pool.HikariPool]HikariPool-115 - Exception during pool initialization.
java.sql.SQLNonTransientConnectionException: Data source rejected establishment of connection, message from server: "Too many connections"
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:110)
at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:97)
at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:122)
at com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:835)
at com.mysql.cj.jdbc.ConnectionImpl.(ConnectionImpl.java:455)
at com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:240)
at com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:199)
at com.zaxxer.hikari.util.DriverDataSource.getConnection(DriverDataSource.java:138)