Question

如何在典型行

中指定与mysql的JDBC连接

DriverManager.getConnection("jdbc:mysql://mysql-o.sourceforge.net:4040/o582544_oopp", "user", "pass");

我从sourceforge请求远程访问，但使用给定的端口4040我无法连接到它。

这是错误：

    Driver Loaded.
Exception in thread "main" com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
    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.<init>(MysqlIO.java:344)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2333)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2370)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2154)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:792)
    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:381)
    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 TestMySQL.main(TestMySQL.java:17)
Caused by: java.net.ConnectException: Connection refused: connect
    at java.net.PlainSocketImpl.socketConnect(Native Method)
    at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:351)
    at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:213)
    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:200)
    at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
    at java.net.Socket.connect(Socket.java:529)
    at java.net.Socket.connect(Socket.java:478)
    at java.net.Socket.<init>(Socket.java:375)
    at java.net.Socket.<init>(Socket.java:218)
    at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:257)
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:294)
    ... 15 more

Process completed.

Answer 1

这里给出了URL语法：

http://dev.mysql.com/doc/refman/5.0/en/connector-j-reference-configuration-properties.html

我认为你有另一个问题。

MySQL的默认端口是3306.我不知道你在哪里获得了这个端口号，或者你正在使用的用户名和密码，但是这条消息告诉我你能够建立连接但MySQL拒绝了你访问。

MySQL授予从特定IP地址访问的权限。我无法想象source forge已经要求您提供IP地址，因此我猜测您的访问权限应该是匿名且只读的。

Answer 2

我没有在堆栈跟踪中看到任何暗示您的请求进入远程服务器的内容，因此我认为您遇到了某种类型的防火墙问题。尝试使用telnet查看您是否正在建立连接：telnet mysql-o.sourceforge.net 4040如果网络允许您通过，您将从服务器获取一些文本。 3306是MySQL的常用端口，所以你可能也想尝试一下。您需要首先解决此部分，然后解决任何许可问题。

JDBC连接到sourceforge的mysql数据库

2 个答案: