com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Com
环境 RedHat Linux 9 VWWare 8.0 SSH 3.2.9 Putty 0.62 MySQL 3.2 问题 通过 JDBC 连接 MySQL 出现 com.mysql.jdbc.exceptions.jdbc4.CommunicationsException:Communications link failure com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Commu
环境
RedHat Linux 9 + VWWare 8.0 + SSH 3.2.9 + Putty 0.62 + MySQL 3.2
问题
通过JDBC连接MySQL出现com.mysql.jdbc.exceptions.jdbc4.CommunicationsException:Communications link failure
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet successfully received from the server was 276 milliseconds ago. The last packet sent successfully to the server was 50 milliseconds ago.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
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:411)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1116)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3591)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3480)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4021)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2490)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2651)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2671)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2621)
at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1557)
at com.mysql.jdbc.ConnectionImpl.loadServerVariables(ConnectionImpl.java:3892)
at com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3437)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2437)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2207)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:797)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
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:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:389)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at TestJDBC.getConnection(TestJDBC.java:19)
at TestJDBC.testResult(TestJDBC.java:76)
at TestJDBC.main(TestJDBC.java:13)
Caused by: java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:3041)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3491)
... 25 more
java.lang.NullPointerException
at TestJDBC.testResult(TestJDBC.java:77)
at TestJDBC.main(TestJDBC.java:13)
</init></init>
解决
尚未完成。还请各位赐教。估计是MySQL版本问题。
参考资料
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
http://stackoverflow.com/questions/2983248/com-mysql-jdbc-exceptions-jdbc4-communicationsexception-communications-link-fai
MySQL第二天早上第一次连接超时报错，解决方法com.mysql.jdbc.exceptions.jdbc4.CommunicationsException:
http://zeusami.iteye.com/blog/1112827
mysql连接com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link
http://blog.sina.com.cn/s/blog_49cc672f0100w5fb.html
linux下jsp环境的配置（支持mysql数据驱动）
http://www.haogongju.net/art/356469
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
http://blog.csdn.net/nemo2011/article/details/6526121
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