Java连接到远程MySQL数据库

本文介绍了Java连接到远程MySQL数据库的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 我想尝试连接到我的远程mysql数据库，我的代码给我这个错误：

java.lang。 ClassNotFoundException：java.security.AccessController.doPrivileged（Native Method）中的 java.URLClassLoader $ a $ r $（$未知源） java.security.AccessController.doPrivileged .URLClassLoader.findClass（未知源）在java.lang.ClassLoader.loadClass（未知源）在sun.misc.Launcher $ AppClassLoader.loadClass（未知源）在java.lang .ClassLoader.loadClass（未知源）在java.lang.Class.forName0（本机方法）在java.lang.Class.forName（未知来源）在Login.login（登录.java：116）在Login.actionPerformed（Login.java:97）在javax.swing.AbstractButton.fireActionPerformed（未知来源）使用credintials（wqdq，dqww）登录 在javax.swing.AbstractButton $ Handler.actionPerformed（未知源）在javax.swing.DefaultButtonModel.fireActionPerformed（未知源）在javax.swing.D efaultButtonModel.setPressed（未知源）在javax.swing.plaf.basic.BasicButtonListener.mouseReleased（未知源）在java.awt.Component.processMouseEvent（未知源）在javax。 swing.JComponent.processMouseEvent（未知源）在java.awt.Component.processEvent（未知源）在java.awt.Container.processEvent（未知源）在java.awt。 Component.dispatchEventImpl（未知源）在java.awt.Container.dispatchEventImpl（未知源）在java.awt.Component.dispatchEvent（未知源）在java.awt.LightweightDispatcher。 retargetMouseEvent（未知源）在java.awt.LightweightDispatcher.processMouseEvent（未知源）在java.awt.LightweightDispatcher.dispatchEvent（未知源）在java.awt.Container.dispatchEventImpl（未知源）在java.awt.Window.dispatchEventImpl（未知源）在java.awt.Component.dispatchEvent（未知源）在java.awt.EventQueue.dispatchEvent（未知来源） at java.awt.EventDispatchThread.pumpOneEventForFilters（未知源）在java.awt.EventDispatchThread.pumpEventsForFilter（未知源）在java.awt.EventDispatchThread.pumpEventsForHierarchy（未知源）在java。 awt.EventDispatchThread.pumpEvents（未知源）在java.awt.EventDispatchThread.pumpEvents（未知源）在java.awt.EventDispatchThread.run（未知来源）

这是我的代码：

连接conn = null; try { String url =jdbc：mysql：// myhost：3306 / mydb; Class.forName（com.mysql.jdbc.Driver）; conn = DriverManager.getConnection（url，myuser，mypass）; System.out.println（建立数据库连接）; } catch（异常e） { e.printStackTrace（）; } finally { if（conn！= null） { try { conn 。关 （）; System.out.println（数据库连接终止）; } catch（异常e）{/ *忽略关闭错误* /} } }

解决方案

您需要在 mysql-Downloads 到你的类路径。您可以按照关于将外部jar添加到Eclipse的说明这里，转到项目属性 - > Java Build Path - >库 - >添加外部JAR

Hey guys im trying to connect to my remote mysql database and my code gives me this error:

java.lang.ClassNotFoundException: com.mysql.jdbc.Driver at java.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Unknown Source) at Login.login(Login.java:116) at Login.actionPerformed(Login.java:97) at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)Logging in with credintials (wqdq, dqww) at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source) at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source) at javax.swing.DefaultButtonModel.setPressed(Unknown Source) at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source) at java.awt.Component.processMouseEvent(Unknown Source) at javax.swing.JComponent.processMouseEvent(Unknown Source) at java.awt.Component.processEvent(Unknown Source) at java.awt.Container.processEvent(Unknown Source) at java.awt.Component.dispatchEventImpl(Unknown Source) at java.awt.Container.dispatchEventImpl(Unknown Source) at java.awt.Component.dispatchEvent(Unknown Source) at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source) at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source) at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source) at java.awt.Container.dispatchEventImpl(Unknown Source) at java.awt.Window.dispatchEventImpl(Unknown Source) at java.awt.Component.dispatchEvent(Unknown Source) at java.awt.EventQueue.dispatchEvent(Unknown Source) at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.run(Unknown Source)

This is my code:

Connection conn = null; try { String url = "jdbc:mysql://myhost:3306/mydb"; Class.forName ("com.mysql.jdbc.Driver"); conn = DriverManager.getConnection (url,"myuser","mypass"); System.out.println ("Database connection established"); } catch (Exception e) { e.printStackTrace(); } finally { if (conn != null) { try { conn.close (); System.out.println ("Database connection terminated"); } catch (Exception e) { /* ignore close errors */ } } }

解决方案

You need to add the JDBC Connector J driver for Mysql database at mysql-Downloads to your classpath. You can follow the instruction on adding the external jars to Eclipse here by going to project properties->Java Build Path -> Libraries->Add External JARs