数据库轮询的问题

[ez7268]

一个小程序，实现mysql数据库轮询。流程为

新建一个连接→判断该连接是否断开，如果断开重新建立→使用该连接查询xx表（每次只查询一行记录，循环等待时间为1秒）

程序在成功从早上9点运行到晚上2点左右报错...

堆栈信息：

com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception:

** BEGIN NESTED EXCEPTION **

java.io.EOFException

STACKTRACE:

java.io.EOFException
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:1934)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2380)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2909)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1600)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1695)
at com.mysql.jdbc.Connection.execSQL(Connection.java:3026)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1137)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1231)
at com.word.DBC.DB_Control.getMsg(DB_Control.java:62)
at com.word.DBC.DB_Control.main(DB_Control.java:185)


** END NESTED EXCEPTION **



Last packet sent to the server was 16 ms ago.
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2592)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:2909)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:1600)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:1695)
at com.mysql.jdbc.Connection.execSQL(Connection.java:3026)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:1137)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:1231)
at com.word.DBC.DB_Control.getMsg(DB_Control.java:62)
at com.word.DBC.DB_Control.main(DB_Control.java:185)
conn is closed,重建连接
com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception:

** BEGIN NESTED EXCEPTION **

java.net.SocketException
MESSAGE: java.net.ConnectException: Connection timed out: connect

STACKTRACE:

java.net.SocketException: java.net.ConnectException: Connection timed out: connect
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:156)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:284)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2569)
at com.mysql.jdbc.Connection.<init>(Connection.java:1485)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:266)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at com.word.uitl.DB_Conn.<init>(DB_Conn.java:21)
at com.word.DBC.DB_Control.getMsg(DB_Control.java:53)
at com.word.DBC.DB_Control.main(DB_Control.java:185)


** END NESTED EXCEPTION **



Last packet sent to the server was 0 ms ago.
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2643)
at com.mysql.jdbc.Connection.<init>(Connection.java:1485)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:266)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at com.word.uitl.DB_Conn.<init>(DB_Conn.java:21)
at com.word.DBC.DB_Control.getMsg(DB_Control.java:53)
at com.word.DBC.DB_Control.main(DB_Control.java:185)
Exception in thread "main" java.lang.NullPointerException
at com.word.DBC.DB_Control.getMsg(DB_Control.java:85)
at com.word.DBC.DB_Control.main(DB_Control.java:185)

[qiule520]

学习.....

[pipi521520]

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource">
<property name="driverClassName">
<value>${db.driver}</value>
</property>
<property name="url">
<value>${db.url}</value>
</property>
<property name="username">
<value>${db.username}</value>
</property>
<property name="password">
<value>${db.password}</value>
</property>
<property name="timeBetweenEvictionRunsMillis">
<value>2000000</value>
</property>
<property name="minEvictableIdleTimeMillis">
<value>1000000</value>
</property> </bean>

如果是spring加上面两句就行

[ez7268]

额...一个小程序用啥spring....

[leavin521]

DB_Control 你仔细检查检查。
怎么突然间就不能加载驱动了

[fengjun332614]

本人也在研究这个问题，是否能提供一下源码？[e-mail]谢谢啦。。