Struts2(九.初始化用户列表时显示用户照片数目)

2018-07-25 13:05:40来源：博客园阅读 ()

1.userlist.jsp

//显示每个用户照片的数目（遍历每个用户）
    $(".picture").each(function(i,e){
        $.post("${pageContext.request.contextPath}/picture/getpicnum",{"picture.uid":e.lang},function(data){
            e.innerHTML=e.innerHTML+"("+ data +")"
        });
    });

2.PictureAction

/**
     * 通过当前用户id（uid）获取在数据库中照片的张数
     * @return
     * @throws ClassNotFoundException
     * @throws SQLException
     * @throws NamingException
     * @throws IOException
     */
    public String getpicnum() throws ClassNotFoundException, SQLException, NamingException, IOException{
        PictureDAO dao=new PictureDAO();
        int num=dao.getPictureNum(picture.getUid());
        out=response.getWriter();
        out.print(num);
        return null;
    }

3.PictureDAO

/**
     * 通过uid（当前用户id）从数据库获得当前用户的所有照片的张数
     * @param id
     * @return
     * @throws SQLException
     * @throws NamingException
     */
    public int getPictureNum(int id) throws SQLException, NamingException{
        if(conn.isClosed())
        {
            Context ctx = new InitialContext();  
            DataSource ds = (DataSource) ctx.lookup("java:comp/env/jdbc/mysql");  
            conn = ds.getConnection();
        }
        int num = 0;
        sql="select count(*) from pictures where uid = ?";
        ps=conn.prepareStatement(sql);
        ps.setInt(1, id);
        ResultSet rs = ps.executeQuery();
        while(rs.next()){
            num=rs.getInt(1);
        }
        conn.close();
        return num;
    }