java连接数据库 - thehappyyouth
java连接数据库
首先有mysql-connector-java-5.1.20-bin.jar
package jdbc;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
public class JDBC_Connection {
static String drivername=”com.mysql.jdbc.Driver”;
static String url=”jdbc:mysql://localhost:3306/test”;
static String username=”root”;
static String password=”root”;
static{
try {
Class.forName(drivername);
System.out.println(“创建驱动成功 “);
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public static Connection getConnection(){
Connection conn=null;
try{
conn=(Connection)DriverManager.getConnection(url,username,password);
System.out.println(“连接数据库成功”);
}catch(SQLException e){
e.printStackTrace();
}
return conn;
}
public static void free(ResultSet rs,Connection conn,Statement stmt){
if(rs!=null)
try {
rs.close();
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.println(“关闭ResultSet失败”);
e.printStackTrace();
}finally{
try {
if(conn!=null)
conn.close();
System.out.println(“关闭成功”);
} catch (SQLException e) {
// TODO Auto-generated catch block
System.out.println(“关闭Connection失败”);
e.printStackTrace();
}finally{
try{
if(stmt!=null)
stmt.close();
}catch(SQLException e){
System.out.println(“关闭Statement失败”);
e.printStackTrace();
}
}
}
}
public static void main(String[] args){
ResultSet rs = null;
Connection conn = null;
Statement stmt = null;
JDBC_Connection.getConnection();
JDBC_Connection.free(rs, conn, stmt);
}
}