java数据库封装

package com.lc.util

import java.sql.Connection

import java.sql.DriverManager

import java.sql.PreparedStatement

import java.sql.ResultSet

import java.sql.SQLException

import java.sql.Statement

public class Datebase{

public Connection conn=null

public Statement stmt=null

public ResultSet rs=null

public PreparedStatement preparedstmt=null

private static String dbDriver="com.mysql.jdbc.Driver"

private static String dbUrl="jdbc:mysql://localhost/graduatedmanager?useUnicode=true&characterEncoding=gb2312"

private static String dbUser="root"

private static String dbPwd="root"

//打开数据库连接

public Datebase(){}

public static Connection getConnection()

{

java.sql.Connection conn=null

try

{

Class.forName(dbDriver)

conn=DriverManager.getConnection(dbUrl,dbUser,dbPwd)

}

catch(Exception e)

{

e.printStackTrace()

}

if(conn==null)

{

System.err.println("警告：数据库连接失败！")

}

return conn

}

//读取结果集

public ResultSet doQuery(String sql)

{

try

{

conn=Datebase.getConnection()

stmt=((java.sql.Connection) conn).createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY)

rs=stmt.executeQuery(sql)

}

catch(SQLException e)

{

e.printStackTrace()

}

return rs

}

//更新数据

public int Prepared_doUpdate(String sql,String parameters[])

{

int result=0

try

{

conn=Datebase.getConnection()

preparedstmt=conn.prepareStatement(sql)

/* for(int i=0i<parameters.lengthi++)

{

System.out.println(parameters[i])

}*/

if(parameters!=null)

{

for(int i=0i<parameters.lengthi++)

{

preparedstmt.setString(i+1,parameters[i])

}

}

result=preparedstmt.executeUpdate()

}

catch(SQLException e)

{

e.printStackTrace()

System.out.println(" *** 作失败")

result=0

}

return result

}

//更新数据

public int doUpdate(String sql)

{

int result=0

try

{

conn=Datebase.getConnection()

stmt=((java.sql.Connection) conn).createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE,ResultSet.CONCUR_READ_ONLY)

result=stmt.executeUpdate(sql)

}

catch(SQLException e)

{

result=0

}

return result

}

//关闭数据库连接

public void closeConnection()

{

try

{

if(rs!=null)

rs.close()

}

catch(Exception e)

{

e.printStackTrace()

}

try

{

if(conn!=null)

((Statement) conn).close()

}

catch(Exception e)

{

e.printStackTrace()

}

}

}

java本身对数据库没有封装,对数据库封装好的有hibernate,ibatis(mybatis),hibernate封装的比较彻底,基本 *** 作不用自己写SQL语句,ibatis的话还是要自己写SQL语句,比较灵活.

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