Question

堆栈跟踪：

Exception in thread "main" org.hibernate.exception.JDBCConnectionException: Could not open connection
    at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:67)
    at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:49)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125)
    at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110)
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.obtainConnection(LogicalConnectionImpl.java:304)
    at org.hibernate.engine.jdbc.internal.LogicalConnectionImpl.getConnection(LogicalConnectionImpl.java:169)
    at org.hibernate.engine.transaction.internal.jdbc.JdbcTransaction.doBegin(JdbcTransaction.java:67)
    at org.hibernate.engine.transaction.spi.AbstractTransactionImpl.begin(AbstractTransactionImpl.java:160)
    at org.hibernate.internal.SessionImpl.beginTransaction(SessionImpl.java:1396)
    at com.telusko.DemoHibb.App.main(App.java:24)

我的Hibernate.cfg.xml文件是：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/neon</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">root</property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="hbm2ddl.auto">update</property>
    </session-factory>
</hibernate-configuration>

Answer 1

请检查您的MySQL服务器是否正在运行：

对于Unix （sh）：

sudo netstat -npl | grep 3306

对于Windows （cmd）：

netstat -aon | find /i "3306"

如果为空，则运行MySQL服务器或更改端口

Answer 2

问题在于旧版本的MySQL Connector / J与MySQL 8的兼容性。简单来说，我必须将SQL Connector版本升级为最新版本。

经过大量的努力，我能够找到问题所在。

我正在使用休眠将Java程序连接到mysql数据库，但出现错误

2 个答案: