我尝试将本地Java应用程序连接到远程mySQL服务器。我有shell访问服务器及其mySQL,但没有root访问权限。
我尝试实现一些我在网上找到的代码,似乎可以实现这个目标。首先我通过SSH连接到服务器,然后尝试访问mySQL数据库。但是,我收到以下错误:
Jul 09, 2014 2:20:06 PM [myClassName] connect
SEVERE: null, message from server: "Host '[remoteHost]' is not allowed to connect to this MySQL server"
据我所知,mySQL默认不允许远程客户端访问,但我不明白的是,在这种情况下,它似乎不允许自己访问自己的mySQL服务器。 (即错误消息中的[" remoteHost"]与托管我试图访问的mySQL服务器的主机是同一主机。)
我正在使用的代码模板如下。出于此问题的目的,我已将所有字段(用户,通行证,主机等)与模板上的字段相同。
我是否需要让系统管理员给我特殊权限?我通过终端访问mySQL服务器没有问题。在此先感谢大家
归功于Kahimyang项目(http://kahimyang.info/kauswagan/code-blogs/1337/ssh-tunneling-with-java-a-database-connection-example)。
import java.util.logging.Logger;
import com.jcraft.jsch.*;
import java.util.logging.Level;
public class MysqlManager {
// Logger
private final static Logger LOGGER =
Logger.getLogger(MysqlManager.class.getName());
public static void main(String args[]) {
MysqlManager mng = new MysqlManager ();
mng.connect();
}
public void connect() {
//
int assigned_port;
final int local_port=3309;
// Remote host and port
final int remote_port=3306;
final String remote_host="kahimyang.info";
try {
JSch jsch = new JSch();
// Create SSH session. Port 22 is your SSH port which
// is open in your firewall setup.
Session session = jsch.getSession("user", remote_host, 22);
session.setPassword("ssh_password");
// Additional SSH options. See your ssh_config manual for
// more options. Set options according to your requirements.
java.util.Properties config = new java.util.Properties();
config.put("StrictHostKeyChecking", "no");
config.put("Compression", "yes");
config.put("ConnectionAttempts","2");
session.setConfig(config);
// Connect
session.connect();
// Create the tunnel through port forwarding.
// This is basically instructing jsch session to send
// data received from local_port in the local machine to
// remote_port of the remote_host
// assigned_port is the port assigned by jsch for use,
// it may not always be the same as
// local_port.
assigned_port = session.setPortForwardingL(local_port,
remote_host, remote_port);
} catch (JSchException e) {
LOGGER.log(Level.SEVERE, e.getMessage()); return;
}
if (assigned_port == 0) {
LOGGER.log(Level.SEVERE, "Port forwarding failed !");
return;
}
// Database access credintials. Make sure this user has
// "connect" access to this database;
// these may be initialized somewhere else in your code.
final String database_user="user";
final String database_password="password";
final String database = "database";
// Build the database connection URL.
StringBuilder url =
new StringBuilder("jdbc:mysql://localhost:");
// use assigned_port to establish database connection
url.append(assigned_port).append ("/").append(database).append ("?user=").
append(database_user).append ("&password=").
append (database_password);
try {
Class.forName(
"com.mysql.jdbc.Driver").newInstance();
java.sql.Connection connection =
java.sql.DriverManager.getConnection(url.toString());
java.sql.DatabaseMetaData metadata = connection.getMetaData();
// Get all the tables and views
String[] tableType = {"TABLE", "VIEW"};
java.sql.ResultSet tables = metadata.getTables(null, null, "%", tableType);
String tableName;
while (tables.next()) {
tableName = tables.getString(3);
// Get the columns from this table
java.sql.ResultSet columns =
metadata.getColumns(null, tableName, null, null);
String columnName;
int dataType;
while (columns.next()) {
columnName = columns.getString(4);
dataType = columns.getInt(5);
// Your actual task;
}
}
} catch (ClassNotFoundException |
IllegalAccessException |
InstantiationException |
java.sql.SQLException e) {
LOGGER.log(Level.SEVERE, e.getMessage());
}
}
}
答案 0 :(得分:0)
要确定您的问题是否与Java相关,您可以尝试telnet
到SQL服务器。
$ telnet localhost 3306
如果您不允许连接,您将收到与您类似的错误消息。 要允许访问,系统管理员需要运行以下内容:
$ mysql -u root -p
Enter password:
mysql> use mysql
mysql> GRANT ALL ON *.* to root@'localhost' IDENTIFIED BY 'your-root-password';
mysql> FLUSH PRIVILEGES;
关于您的顾虑(SQL服务器禁止从localhost访问):只有在必要时才允许访问。因此,如果您只有远程SQL客户端,则无需允许来自主机localhost
的访问。