数据库存储图片 Blod格式2（下载）

此文接上篇 主要想讲一下图片的下载 

框架背景 ：spring + hibernate 

看代码  ok 走你

public void getDate(HttpServletRequest request, HttpServletResponse response,String id) throws Exception {
        Connection conn = null;
        PreparedStatement ps =null;
        ResultSet rs = null;
        response.reset();
        //response.setContentType("image/*;charset=GBK");
        //response.setContentType("image/jpeg");
        //response.setContentType("text/html; charset=GBK");
        response.setContentType("unknown"); 
        
        try{
            conn = DataSourceUtils.getConnection(jdbcTemplate.getDataSource());
            String sql = "select img，msg，filename from "+tableName+" where id = " +"'"+id+"'";
            System.out.println(sql);
            ps = conn.prepareStatement(sql);
            rs = ps.executeQuery();
            if(rs.next()){
                Blob blob = rs.getBlob("img");
                String name=rs.getString("filename");
                response.addHeader("content-disposition", "attachment;filename="" + name+""");
                //response.setContentType("application/x-download"); 
                //response.setContentType("application/x-msdownload");
                //response.addHeader("Content－Disposition","attachment;filename="+clmc+"."+cllx);
                InputStream pi = blob.getBinaryStream();
                OutputStream sos = response.getOutputStream();
                byte bytes[] = new byte[(int)((BLOB)blob).length()];
                for(int n = 0; (n = pi.read(bytes)) != -1;)sos.write(bytes, 0, n);
                pi.close();
                sos.flush();
            }
        }catch(Exception ex){
            DataSourceUtils.releaseConnection(conn, jdbcTemplate.getDataSource());
            throw new Exception("执行时出错!" + ex.getMessage());
        }finally{
            if(rs!=null)rs.close();
            if(ps!=null)ps.close();
            if(conn!=null){
                try{
                    DataSourceUtils.releaseConnection(conn,jdbcTemplate.getDataSource());
                }catch(Exception ex){
                    ex.printStackTrace();
                }
            }
        }
    }

看完之后你会发现 其实很简单

就是 用

 response.addHeader("content-disposition", "attachment;filename="" + name+""");
嗯

下一篇可能要学一下 request 和 respones 的一些讲解（当然也是来自网络的资源我是小白 自己做好 学习笔记就好 ）