syslog.java

本例利用java和jsp实现电子政务系统中涉及到的档案管理系统。涉及到javabean和jsp的使用技巧。

package com.csbook.documentsystem;

/**
 * <p>Title: </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2003</p>
 * <p>Company: </p>
 * @author not attributable
 * @version 1.0
 */

import javax.naming.*;
import javax.sql.*;
import java.sql.*;
import java.util.*;

public class SysLog{
   Context ctx=null;
   DataSource ds=null;
   SysLog log=null;
   ChangeEncoding ce=null;
   //构造函数
  public SysLog()
   {
     //从连接池中获取数据库连接
     try{
       ctx = new InitialContext();
       ds = (DataSource) ctx.lookup("documents");
     }
     catch(NamingException e){
        e.printStackTrace();
    }
    ce=new ChangeEncoding();
   }

   //添加系统日志
   //operator为进行操作的用户，operation为进行的操作，table为操作的表
   public void addLog(String operator,String operation,String table)
   {
     Connection con = null;
     PreparedStatement ps = null;
     try {
           String sqlupdate = "insert into syslog(operator,operation,tablename) values(?,?,?)";
           con=ds.getConnection();
           ps=con.prepareStatement(sqlupdate);
           ps.setString(1,operator);
           ps.setString(2,operation);
           ps.setString(3,table);
           ps.executeUpdate();
         }
      catch(SQLException e){
         e.printStackTrace();
         }
      finally{
             if (ps != null)  try {ps.close();}
                catch (SQLException ignore) {}
             if (con != null)   try {con.close();}
                catch (SQLException ignore) {}
        }
   }


   //添加与用户的交互信息
   //from为消息的建立者，如有系统自动生成，则输入“system”
   //to为消息的接收者，message为消息内容
   //state为该条消息的状态，1表示消息接受者尚未阅读该消息，0表示已读
   public void addMsg(String from,String to,String message,int state)
   {
     Connection con = null;
     PreparedStatement ps = null;
     try{
       String sqlInsert="insert into messages(fromUser,toUser,message,state) values(?,?,?,?)";
       con=ds.getConnection();
       ps=con.prepareStatement(sqlInsert);
       ps.setString(1,from);
       ps.setString(2,to);
       ps.setString(3,message);
       ps.setInt(4,1);
       ps.executeUpdate();
     }
     catch(SQLException e){
        e.printStackTrace();
     }
     finally{
             if (ps != null)  try {ps.close();}
                catch (SQLException ignore) {}
             if (con != null)   try {con.close();}
                catch (SQLException ignore) {}
     }
   }

   //获取消息内容
  //to为消息的接受者,state为消息的状态
   public ArrayList getMsg(String to,int state)
   {
     Connection con = null;
     PreparedStatement ps = null;
     ResultSet rs=null;
     ArrayList message=new ArrayList();
     try{
       String sqlQuery="select * from messages where toUser=? and state=?";
       con=ds.getConnection();
       ps=con.prepareStatement(sqlQuery);
       ps.setString(1,to);
       ps.setInt(2,state);
       rs=ps.executeQuery();
       String temp;
       while(rs.next()){
         temp=rs.getString("id")+" "+ce.changeCharset(rs.getString("message"));
         message.add(temp);
        }
     }
     catch(SQLException e){
        e.printStackTrace();
     }
     finally{
         if (rs != null)   try {rs.close();}
                catch (SQLException ignore) {}
         if (ps != null)  try {ps.close();}
                catch (SQLException ignore) {}
         if (con != null)   try {con.close();}
                catch (SQLException ignore) {}
     }
     return message;
   }

   //设置消息状态为“已读”
   //id为消息编号
   public void setMsgOver(int id)
   {
     Connection con = null;
     PreparedStatement ps = null;
     try{
       String sqlUpdate="update messages set state=0 where id=?";
       con=ds.getConnection();
       ps=con.prepareStatement(sqlUpdate);
       ps.setInt(1,id);
       ps.executeUpdate();
     }
     catch(SQLException e){
        e.printStackTrace();
     }
     finally{
       if (ps != null)  try {ps.close();}
                catch (SQLException ignore) {}
       if (con != null)   try {con.close();}
                catch (SQLException ignore) {}
     }
   }
}