albumadminservlet.java

jsp+javabean写的论坛

package com.alumni.servlet;
import java.io.*;
import java.sql.*;
import javax.servlet.jsp.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.util.*;
import com.alumni.bean.*;

public class AlbumAdminServlet extends HttpServlet
{
	ServletConfig config;
	//初始化
	public void init(ServletConfig config) throws ServletException
	{
		super.init(config);
		this.config=config;
	}
	//调用doPost方法
	public void doGet(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException
	{
		this.doPost(request,response);
	}
	//doPost核心方法
	public void doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException
	{
		DBConnection dbConn=null;
		Connection conn=null;
		Statement stmt=null;
		
		String serverUrl=null;
		String[] delete=null;
		
		//session
		HttpSession session=request.getSession();
		//out
		PrintWriter out=response.getWriter();
		//application
		ServletContext application=this.getServletConfig().getServletContext();
		
		//取得服务器路径
		serverUrl=application.getRealPath("/upload/album/");
		
		//判断是否登陆过
		Boolean hasLogin=(Boolean)session.getAttribute("hasLogin");
		
		if(hasLogin!=null&&hasLogin.booleanValue()==true)
		{
			try
			{
				delete=request.getParameterValues("id");
				if(delete==null)
				{
					//没有选中任何东西就返回到原来的页面
					response.sendRedirect("/album.jsp");
				}
				else
				{
					
					//连接到数据库
					dbConn=new DBConnection();
					conn=dbConn.getConnectionToAccess(application.getRealPath("db/alumni.mdb"));
					stmt=conn.createStatement();
					
					//删除上传的图片文件
					for(int i=0;i<delete.length;i++)
					{
						String search="SELECT PIC_NAME FROM ALBUM WHERE ID="+delete[i];
						ResultSet tempRs=stmt.executeQuery(search);
						while(tempRs.next())
						{
							String fileUrl=serverUrl+"\\"+tempRs.getString("PIC_NAME");
							File deleteFile=new File(fileUrl);
							if(deleteFile.exists())
							{
								//如果文件存在就删除它
								deleteFile.delete();
							}
							else
							{
								if(dbConn!=null)
								{
									dbConn.close();
								}
								out.println(deleteFile);
							}
						}
					}
					
					//删除数据库中有图片的记录
					StringBuffer makeDelete=new StringBuffer();
					for(int i=0;i<delete.length;i++)
					{
						makeDelete.append(delete[i]);
						if(i!=delete.length-1)
						{
							makeDelete.append(",");
						}
					}
					String deleteSql="DELETE FROM ALBUM WHERE ID IN("+makeDelete.toString()+")";
					stmt.executeUpdate(deleteSql);
					
					//关闭数据库
					if(dbConn!=null)
					{
						dbConn.close();
					}
					//全部处理完后成功返回
					response.sendRedirect("/album.jsp");
				}
			}
			catch(SQLException sqle)
			{
				if(dbConn!=null)
				{
					dbConn.close();
				}
				response.sendRedirect("/error.jsp?code=SQLException");
			}
			catch(Exception e)
			{
				if(dbConn!=null)
				{
					dbConn.close();
				}
				response.sendRedirect("/error.jsp?code=Exception");
			}
		}
		else
		{
			//未登陆
			if(dbConn!=null)
			{
				dbConn.close();
			}
			response.sendRedirect("/login.jsp");
		}

	}
}