IT工程師數位筆記本

import java.sql.DriverManager;import java.sql.SQLException;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;public class DBUtil{  private static final String DBDRIVER="com.mysql.jdbc.Driver";//驅動類類名  private static final String DBNAME="test";//數據庫名  private static final String DBURL="jdbc:mysql://localhost:3306/"+DBNAME;//連接URL  private static final String DBUSER="root";//數據庫用戶名  private static final String DBPASSWORD="root";//數據庫密碼  private static Connection conn=null;  private static PreparedStatement ps=null;  private static ResultSet rs=null;  //獲取數據庫連接  public static Connection getConnection(){    try{        Class.forName(DBDRIVER);//注冊驅動        conn=DriverManager.getConnection(DBURL,DBUSER,DBPASSWORD);//獲得連接對象    }catch(ClassNotFoundException e){//捕獲驅動類無法找到異常           e.printStackTrace();    }catch(SQLException e){//捕獲SQL異常           e.printStackTrace();    }    return conn;  }  //查詢數據  public ResultSet select(String sql)throws Exception{    try{        conn=getConnection();        ps=conn.prepareStatement(sql);        rs=ps.executeQuery(sql);    return rs;    }catch(SQLException sqle){        throw new SQLException("select data Exception: "+sqle.getMessage());    }catch(Exception e){        throw new Exception("System error: "+e.getMessage());    }  }  //插入數據  public int insert(String sql)throws Exception{    int num=0;//計數    try{        conn=getConnection();        ps=conn.prepareStatement(sql);        num=ps.executeUpdate();    }catch(SQLException sqle){        throw new SQLException("insert data Exception: "+sqle.getMessage());    }finally{        try{            if(ps!=null){               ps.close();            }        }catch(Exception e){            throw new Exception("ps close exception: "+e.getMessage());        }        try{            if(conn!=null){               conn.close();            }        }catch(Exception e){            throw new Exception("conn close exception: "+e.getMessage());        }    }    return num;  }  //刪除數據  public int delete(String sql)throws Exception{    int num=0;//計數    try{        conn=getConnection();        ps=conn.prepareStatement(sql);        num=ps.executeUpdate();    }catch(SQLException sqle){        throw new SQLException("delete data Exception: "+sqle.getMessage());    }finally{        try{            if(ps!=null){                ps.close();            }        }catch(Exception e){            throw new Exception("ps close Exception: "+e.getMessage());        }        try{            if(conn!=null){                conn.close();            }        }catch(Exception e){            throw new Exception("conn close Exception: "+e.getMessage());        }    }    return num;  }  //修改數據  public int update(String sql)throws Exception{    int num=0;//計數    try{        conn=getConnection();        ps=conn.prepareStatement(sql);        num=ps.executeUpdate();    }catch(SQLException sqle){        throw new SQLException("update data Exception: "+sqle.getMessage());    }finally{        try{            if(ps!=null){                ps.close();            }        }catch(Exception e){            throw new Exception("ps close Exception: "+e.getMessage());        }        try{            if(conn!=null){                conn.close();            }        }catch(Exception e){            throw new Exception("conn close Excepiton: "+e.getMessage());        }    }    return num;  }}

不含病毒。www.avast.com