Ubuntu上的MySQL異常：com.mysql.jdbc.exceptions.jdbc4.CommunicationsException：通信鏈接失敗

Question

我無法連接下面提到的示例中的mysql db。

類JDBCTest {

private static final String url = "jdbc:mysql://localhost"; 

private static final String user = "root"; 

private static final String password = "abc"; 

public static void main(String args[]) { 
    try { 
     Connection con = DriverManager.getConnection(url, user, password); 
     System.out.println("Success"); 

    } catch (Exception e) { 
     e.printStackTrace(); 
    } 
} } 

堆棧跟蹤如下：

Caused by: org.springframework.jdbc.CannotGetJdbcConnectionException: 
Could not get JDBC Connection; nested exception is 
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure 
property file provide to spring contains: jdbcDriverClassName=com.mysql.jdbc.Driver 
jdbcUrl=jdbc:mysql://localhost:3306/mynumber jdbcUsername=root jdbcPassword=rock 

Answer 1

是在classpath你的MySQL連接器jar文件？另外，你如何加載你的MySQL JDBC驅動程序。它應該如下所示：

try { 
    Class.forName("com.mysql.jdbc.Driver"); 
    Connection con = DriverManager.getConnection(url, user, password); 
    System.out.println("Success"); 

} catch (Exception e) { 
    e.printStackTrace(); 
}