我试图连接到我的MySQL数据库,并得到“无法连接到数据库”异常。任何人都可以发现我做错了什么吗?“无法连接到数据库”
public class SQL {
//database variables
private Connection connection;
public SQL() {
// DATABASE CONNECTION
try {
Class.forName("com.mysql.jdbc.Driver").newInstance();
} catch (Exception e) {
System.err.println("Unable to find and load driver");
System.exit(1);
}
try {
connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/tools");
} catch (SQLException e){
System.out.println("Unable to connect to database");
System.exit(1);
}
}
public void database() {
Vector<String> v = new Vector<String>();
try {
Statement statement = connection.createStatement();
ResultSet rs = statement
.executeQuery("SELECT nameofsong FROM lyrics_lyrics");
while (rs.next()) {
v.addElement(rs.getString("nameofsong"));
}
rs.close();
} catch (SQLException e) { }
}
private void displaySQLErrors(SQLException e){
System.out.println("SQLException: " + e.getMessage());
System.out.println("SQLState: " + e.getSQLState());
System.out.println("VendorError: " + e.getErrorCode());
}
}
您可以使用e.printStackTrace()打印异常的堆栈跟踪吗?并发布输出。 – Andy
请发布完整的stacktrace。 –
你指定了用户名和密码吗? – Cyntech