新闻树形展示

一、问题描述

将所有类别的新闻导入数据库中。以树形目录形式展示新闻类别，每个树形节点代表新闻分类，选择每个新闻，以列表形式显示新闻标题，点击新闻标题，可以查看详细信息。

二、实现

1、将excel导入到navicat中

 

 2、在eclispe中编写代码：

实体层封装新闻：

public class Passage {
    private int id;
    private String content;
    private String channelName;
    private String title;
    public String getContent() {
        return content;
    }
    public void setContent(String content) {
        this.content = content;
    }
    public String getChannelName() {
        return channelName;
    }
    public void setChannelName(String channelName) {
        this.channelName = channelName;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    public Passage(int id,String content, String channelName, String title) {
        super();
        this.id=id;
        this.content = content;
        this.channelName = channelName;
        this.title = title;
    }
    public Passage() {
        super();
        // TODO 自动生成的构造函数存根
    }
    

}

Dao层实现查找新闻：

public class passageDao {
    
    /**
     * 获取总记录数和总页数
     * @param count
     * @return
     */
    
    public static int[] totalPage(int count, String keyword,String type) {
        // 0 总记录数， 1， 页数
        int arr[] = {0, 1};
        
        Connection conn = Basedao.getconn();
        PreparedStatement ps = null;
        ResultSet rs = null;
        
        try {
            String sql = "";
            
            if(keyword!=null) {
                sql = "select count(*) from "+type+" where id like ?";
                ps = conn.prepareStatement(sql);
                ps.setString(1, "%"+keyword+"%");
            }else{
                sql = "select count(*) from "+type;
                
                ps = conn.prepareStatement(sql);
                
            }
            
             rs = ps.executeQuery();
             
             while(rs.next()) {
                 arr[0]= rs.getInt(1);
                 
                 if(arr[0]%count==0){
                     arr[1] = arr[0]/count;
                 }else{
                     arr[1] = arr[0]/count+1;
                 }
             }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            Basedao.closeall(rs, ps, conn);
        }
        
        return arr;
    }
    
    public static ArrayList<Passage> selectAll(int cpage, int count,String keyword,String type){
        ArrayList<Passage> list = new ArrayList<Passage>();
        //声明结果集
                ResultSet rs = null;
                //获取连接对象
                Connection conn = Basedao.getconn();            
                PreparedStatement ps = null;    
                try {
                    String sql = "";
                    
                    if(keyword!=null) {
                        sql = "select * from "+type+" where id like ? limit ?, ?";
                         ps = conn.prepareStatement(sql);
                         ps.setString(1, "%"+keyword+"%");
                         ps.setInt(2, (cpage-1)*count);
                         ps.setInt(3, count);
                    }else{
                    
                        sql = "select * from "+type+" limit ?, ?";
                         ps = conn.prepareStatement(sql);
                         
                         ps.setInt(1, (cpage-1)*count);
                         ps.setInt(2, count);
                    }
                     rs = ps.executeQuery();                 
                     while(rs.next()) {
                         Passage u = new Passage(
                                 rs.getInt("id"),
                                     rs.getString("content"),
                                     rs.getString("channelName"),
                                    rs.getString("title")
                                 );                         
                         list.add(u);                 
                     }     
                } catch (SQLException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                } finally {
                    Basedao.closeall(rs, ps, conn);
                }

                return list;
            }
    /**
     * 通过ID查找用户
     * @param cpage
     * @param count
     * @param keyword
     * @return
     */
    public static String selectById(int id,String type) {

        Passage u = null;
        
        //声明结果集
        ResultSet rs = null;
        //获取连接对象
        Connection conn = Basedao.getconn();
        
        PreparedStatement ps = null;
        
        String content = null;
        try {
            String sql = "select content from "+type+" where id=?";
            //执行
             ps = conn.prepareStatement(sql);
             //传id
             ps.setInt(1, id);
            
             
             rs = ps.executeQuery();
             
             while(rs.next()) {
                content=rs.getString("content");
    
             }
             
             
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            Basedao.closeall(rs, ps, conn);
        }

        return content;
    }
    

}

Servlet层实现界面与后台交互：

public class select extends HttpServlet {
    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub    
        int cpage = 1; //当前页
        int count = 15; //每页显示条数    
        //获取用户指定的页面
        String cp = request.getParameter("cp");
        String type=request.getParameter("type");
        //接收用户搜索的关键字
        String keyword = request.getParameter("keywords");    
        if(cp!=null)
        {
            cpage = Integer.parseInt(cp);
        }
        int arr[] = passageDao.totalPage(count, keyword,type);    
        //获取所有用户记录
        ArrayList<Passage>    list= passageDao.selectAll(cpage, count, keyword,type);    
        ArrayList<Passage> json;
        for(int i=0;i<list.size();i++) {
                JSONObject ob=new JSONObject();
                ob.put("title", list.get(i).getTitle());
                System.out.println(list.get(i).getTitle());
            }    
        //放到请求对象域里
        request.setAttribute("type", type);
        request.setAttribute("userlist", list);
        request.setAttribute("tsum", arr[0]);
        request.setAttribute("tpage", arr[1]);
        request.setAttribute("cpage", cpage);    
        if(keyword != null) {
            request.setAttribute("searchParams", "&keywords="+keyword);
        }    
        request.getRequestDispatcher("caijing.jsp").forward(request, response);    
    }

    
}

页面调用框架：

三、结果展示

实现分页：

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