newsdao.java

用户能添加 查看 新闻内容 并能够修改新闻内容~

package news.db;
import news.db.*;
import news.form.*;
import java.sql.*;
import java.util.*;
public class NewsDAO{
    public int insert(News n){
    	Connection con = null;
    	int k=0;
    	PreparedStatement pstmt = null;
    	String sql = "";
    	sql = "insert into news(title,author,content,pubtime)values(?,?,?,now())";
    	try{
         	  con = DatabaseConnection.getCon();
         	  pstmt = con.prepareStatement(sql);
         	  pstmt.setString(1,n.getTitle());
         	  pstmt.setString(2,n.getAuthor());
         	  pstmt.setString(3,n.getContent());
         	  k=pstmt.executeUpdate();
     		
         	}catch(Exception e){e.printStackTrace();
         }
         	finally{
			try{
				if(con!=null){
					con.close();
				}
			}catch(Exception e2){}
		} 
		return k;
   } 
   
   
   public ArrayList searchAll(){
    	Connection con = null;
    	PreparedStatement pstmt = null;
    	String sql = "";
    	ResultSet rs = null;
    	News n=null;
    	sql = "select * from news";
    	ArrayList ar = new ArrayList();
    	try{
         	  con = DatabaseConnection.getCon();
         	  pstmt = con.prepareStatement(sql);
         	  rs = pstmt.executeQuery();
         	  while(rs.next()){
         	  	n = new News();
         	  	n.setTitle(rs.getString("title"));
         	  	n.setAuthor(rs.getString("author"));
         	  	n.setContent(rs.getString("content"));
         	  	n.setPubtime(rs.getDate("pubtime"));
         	  	n.setId(rs.getInt("id"));
         	  	ar.add(n);
         	  	}     		
         	}catch(Exception e){e.printStackTrace();
         }
         	finally{
			try{
				if(con!=null){
					con.close();
				}
			}catch(Exception e2){}
		} 
		return ar;
   } 
   public int delete(String aa){
    	Connection con = null;
    	int k=0;
    	PreparedStatement pstmt = null;
    	String sql = "";
    	sql = "delete from news where id=?";
    	try{
         	  con = DatabaseConnection.getCon();
         	  pstmt = con.prepareStatement(sql);
         	  pstmt.setString(1,aa);
         	  k=pstmt.executeUpdate();
     		
         	}catch(Exception e){e.printStackTrace();
         }
         	finally{
			try{
				if(con!=null){
					con.close();
				}
			}catch(Exception e2){}
		} 
		return k;
   } 
   
   public News search(String id){
    	Connection con = null;
    	PreparedStatement pstmt = null;
    	String sql = "";
    	ResultSet rs = null;
    	News u = new News();
    	sql = "select * from news where id=?";
    	try{
         	  con = DatabaseConnection.getCon();
         	  pstmt = con.prepareStatement(sql);
         	  pstmt.setString(1,id);
         	  rs = pstmt.executeQuery();
         	  if(rs.next()){
         	  	u.setId(rs.getInt("id"));
         	  	u.setTitle(rs.getString("title"));
         	  	u.setAuthor(rs.getString("author"));
         	  	u.setContent(rs.getString("content"));
         	  	u.setPubtime(rs.getDate("pubtime"));
         	  	}     		
         	}catch(Exception e){e.printStackTrace();
         }
         	finally{
			try{
				if(con!=null){
					con.close();
				}
			}catch(Exception e2){}
		} 
		return u;
   }  
   
   
   public int update(News u){
    	Connection con = null;
    	int k=0;
    	PreparedStatement pstmt = null;
    	String sql = "";
    	sql = "update news set title=?,author=?,content=? where id=?";
    	try{
         	  con = DatabaseConnection.getCon();
         	  pstmt = con.prepareStatement(sql);
         	  pstmt.setString(1,u.getTitle());
         	  pstmt.setString(2,u.getAuthor());
         	  pstmt.setString(3,u.getContent());
         	  pstmt.setInt(4,u.getId());
        
         	  k=pstmt.executeUpdate();
     		
         	}catch(Exception e){e.printStackTrace();
         }
         	finally{
			try{
				if(con!=null){
					con.close();
				}
			}catch(Exception e2){}
		} 
		return k;
   } 
 }