JDBC三种方式加载数据库驱动（源码）

JDBC三种方式加载数据库驱动（源码）下面以Mysql为例：

1.

 

import java.sql.DriverManager;import java.sql.Connection;import java.sql.Statement;import java.sql.ResultSet;import java.sql.SQLException;

public class JDBCExample{    public static void main(String orgs[]){    try{       Class.forName("com.mysql.jdbc.Driver");//加载数据库驱动       String url="jdbc:mysql://localhost:3306/databasename";//数据库连接子协议       Connection conn=DriverManager.getConnection(url,"username","password");       Statement stmt=conn.createStatement();       ResultSet rs=stmt.executeQuery("select * from tablename");       while(rs.next()){//不断指向下一条记录            System.out.println("DeptNo:"+rs.getInt(1));            System.out.println("/tDeptName:"+rs.getString(2));            System.out.println("/tLOC:"+rs.getString(3));}             rs.close();    stmt.close();    conn.close();}catch(ClassNotFoundException e){   System.out.println("找不到指定的驱动程序类！");}catch(SQLException e){    e.printStackTrace();}}} 

2. import java.sql.DriverManager;import java.sql.Connection;import java.sql.Statement;import java.sql.ResultSet;import java.sql.SQLException;

public class JDBCExample2{    public static void main(String orgs[]){    try{       System.setProperty("jdbc.driver","com.mysql.jdbc.Driver");//系统属性指定数据库驱动       String url="jdbc:mysql://localhost:3306/databasename";//数据库连接子协议       Connection conn=DriverManager.getConnection(url,"username","password");       Statement stmt=conn.createStatement();       ResultSet rs=stmt.executeQuery("select * from tablename");       while(rs.next()){//不断指向下一条记录            System.out.println("DeptNo:"+rs.getInt(1));            System.out.println("/tDeptName:"+rs.getString(2));            System.out.println("/tLOC:"+rs.getString(3));}             rs.close();    stmt.close();    conn.close();}catch(SQLException e){    e.printStackTrace();}}} 

3.

import java.sql.DriverManager;import java.sql.Connection;import java.sql.Statement;import java.sql.ResultSet;import java.sql.SQLException;

public class JDBCExample3{    public static void main(String orgs[]){    try{       new com.mysql.jdbc.Driver();//创建driver对象，加载数据库驱动       String url="jdbc:mysql://localhost:3306/databasename";//数据库连接子协议       Connection conn=DriverManager.getConnection(url,"username","password");       Statement stmt=conn.createStatement();       ResultSet rs=stmt.executeQuery("select * from tablename");       while(rs.next()){//不断指向下一条记录            System.out.println("DeptNo:"+rs.getInt(1));            System.out.println("/tDeptName:"+rs.getString(2));            System.out.println("/tLOC:"+rs.getString(3));}             rs.close();    stmt.close();    conn.close();}catch(SQLException e){    e.printStackTrace();}}}