Question

我正在尝试使用Java代码连接到WAMP服务器中的MySql数据库。服务器位于本地网络内的计算机中。以下是我使用的代码：

public class MySQLAccess {

public static void main(String args[]) {

      String url = "jdbc:mysql://192.168.0.21:3306/";
      String dbName = "mydb";
      String driver = "com.mysql.jdbc.Driver";
      String userName = "root"; 
      String password = "";
      try {
      Class.forName(driver).newInstance();
      Connection conn = DriverManager.getConnection(url+dbName,userName,password);
      System.out.println("Connected to the database");
      conn.close();
      System.out.println("Disconnected from database");
      } catch (Exception e) {
      e.printStackTrace();
      }

我得到以下例外：

com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception: 

** BEGIN NESTED EXCEPTION ** 

java.net.ConnectException
MESSAGE: Connection timed out

STACKTRACE:

java.net.ConnectException: Connection timed out
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:519)
at java.net.Socket.connect(Socket.java:469)
at java.net.Socket.<init>(Socket.java:366)
at java.net.Socket.<init>(Socket.java:209)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:256)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:271)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2771)
at com.mysql.jdbc.Connection.<init>(Connection.java:1555)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at MySQLAccess.main(MySQLAccess.java:24)


** END NESTED EXCEPTION **



    Last packet sent to the server was 1 ms ago.
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2847)
at com.mysql.jdbc.Connection.<init>(Connection.java:1555)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at MySQLAccess.main(MySQLAccess.java:24)

我在此代码中看不到任何明显的异常应该导致此异常。此外，我已经重新确认端口号是正确的，托管机器没有任何防火墙。

这个问题的原因是什么，可能是什么解决方案。任何melp都非常感激。

Answer 1

1.检查你的mysql是否在punticular主机和端口上运行

2.尝试从运行代码的计算机上ping该主机以确保连接（防火墙??）

3.如果您有db ui tool或其他内容，请尝试使用

进行连接

从java连接到MySql时出现异常

1 个答案: