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();
}
}
}

 

 

整理完闭