- Java code
package book.database;import java.sql.Connection;import java.sql.DriverManager;import java.sql.SQLException;public class DBConnector { public static Connection getConnection (String driverClassName,String dbURL,String userName,String password) throws ClassNotFoundException,SQLException{ Connection con=null; Class.forName(driverClassName); con=DriverManager.getConnection(dbURL,userName,password); return con; } public static Connection getMYSQLConnection(String driverClassName,String serverHost,String serverPort,String dbName,String userName,String password) throws ClassNotFoundException,SQLException{ if (driverClassName==null){ driverClassName="com.mysql.jdbc.Driver"; } if(serverHost==null){ serverHost="127.0.0.1"; } if(serverPort==null){ serverPort="3306"; } String dbURL="jdbc:mysql://"+serverHost+":"+serverPort+"/"+dbName; return getConnection(driverClassName,dbURL,userName,password); } public static void main(String[] args) throws ClassNotFoundException,SQLException{ String mySQLDirver ="com.mysql.jdbc.Driver"; String dbName="books"; String userName="root"; String password="123456"; Connection con=DBConnector.getMYSQLConnection(mySQLDirver,null,null,dbName,userName,password); System.out.println("连接mysql数据库成功！"); con.close(); System.out.println("成功关闭与mysql数据库的连接！"); String url="jdbc:mysql://127.0.0.1:3306/"+dbName; con=DBConnector.getConnection(mySQLDirver,url,userName,password); System.out.println("连接mysql数据库成功！"); con.close(); System.out.println("成功关闭与mysql数据库的连接"); }}
只是书上的一个例子。。。照上面代码在eclipse上运行
出现错误
Exception in thread "main" java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:276)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:169)
at book.database.DBConnector.getConnection(DBConnector.java:11)
at book.database.DBConnector.getMYSQLConnection(DBConnector.java:27)
at book.database.DBConnector.main(DBConnector.java:35)
这是eclipse环境没有弄好还是什么的。。我是菜鸟什么都不懂。。。
------解决方案--------------------
------解决方案--------------------
如果楼主用的是eclipse的话，把mysql的驱动包加到项目的环境属性中。选择项目名称右键选"Build Path"-"Configure Build Path"-"Libraries"-"Add External JARS"添加。添加成功后会在Referenced Libraries中看到。经测试以下代码可以成功连接数据库，供楼主参考
- Java code
package com.student.test3;import java.sql.Connection;import java.sql.DriverManager;import java.sql.SQLException;public class DBConnector{ public static Connection getConnection(String driverClassName, String dbURL, String userName, String password) throws ClassNotFoundException, SQLException { Connection con = null; Class.forName(driverClassName); con = DriverManager.getConnection(dbURL, userName, password); return con; } public static Connection getMYSQLConnection(String driverClassName, String serverHost, String serverPort, String dbName, String userName, String password) throws ClassNotFoundException, SQLException { if (driverClassName == null) { driverClassName = "com.mysql.jdbc.Driver"; } if (serverHost == null) { serverHost = "127.0.0.1"; } if (serverPort == null) { serverPort = "3306"; } String dbURL = "jdbc:mysql://" + serverHost + ":" + serverPort + "/" + dbName; return getConnection(driverClassName, dbURL, userName, password); } public static void main(String[] args) throws ClassNotFoundException, SQLException { String mySQLDirver = "com.mysql.jdbc.Driver";//这里的驱动包里面一定要有这个Driver String dbName = "study_java"; String userName = "root"; String password = "mysqladmin"; Connection con = DBConnector.getMYSQLConnection(mySQLDirver, null, null, dbName, userName, password); System.out.println("连接mysql数据库成功！"); con.close(); System.out.println("成功关闭与mysql数据库的连接！"); String url = "jdbc:mysql://127.0.0.1:3306/" + dbName; con = DBConnector.getConnection(mySQLDirver, url, userName, password); System.out.println("连接mysql数据库成功！"); con.close(); System.out.println("成功关闭与mysql数据库的连接"); }}