java mysql连接链接失败连接被拒绝[重复]

Question

当客户端连接到 MySQL 时，抛出以下异常

Last packet sent to the server was 0 ms ago.
        at sun.reflect.GeneratedConstructorAccessor112.newInstance(Unknown Source)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
        at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
        at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2103)
        at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:718)
        at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
        at sun.reflect.GeneratedConstructorAccessor110.newInstance(Unknown Source)
        at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:513)
        at com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
        at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:302)
        at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282)
        at java.sql.DriverManager.getConnection(DriverManager.java:582)
        at java.sql.DriverManager.getConnection(DriverManager.java:154)
        at org.logicalcobwebs.proxool.DefaultConnectionBuilder.buildConnection(DefaultConnectionBuilder.java:39)
        at org.logicalcobwebs.proxool.Prototyper.buildConnection(Prototyper.java:159)
        at org.logicalcobwebs.proxool.ConnectionPool.getConnection(ConnectionPool.java:211)
        at org.logicalcobwebs.proxool.ProxoolDriver.connect(ProxoolDriver.java:89)
        at java.sql.DriverManager.getConnection(DriverManager.java:582)
        at java.sql.DriverManager.getConnection(DriverManager.java:207)
        at com.chinaren.tools.MysqlConnectionPools.getConnection(MysqlConnectionPools.java:652)
        ..........
Caused by: java.net.ConnectException: Connection refused
        at java.net.PlainSocketImpl.socketConnect(Native Method)
        at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
        at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
        at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
        at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
        at java.net.Socket.connect(Socket.java:525)
        at java.net.Socket.connect(Socket.java:475)
        at java.net.Socket.<init>(Socket.java:372)
        at java.net.Socket.<init>(Socket.java:215)
        at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:253)
        at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:280)
        at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2026)
        ... 51 more

1. 客户端能ping通dbServer就OK了
2. 客户端可以telnet dbServer:port is OK
3. 我的电脑连接到 dbServer 上的相同代码是 OK

这是8小时的问题吗？是什么原因？

Answer 1

java.net.ConnectException: Connection refused

：连接被拒绝。这发生在低级别，意味着端口未打开或连接被防火墙主动拒绝。检查 JDBC URL 和/或数据源配置是否实际使用了它应该使用的主机名/IP 和端口。

此外，客户端实际上是从运行此应用程序的同一台计算机执行 ping 和 telnet 操作吗？