将图片以Blob格式存入数据库,再通过Servlet显示到界面

1:为了方便测试,直接将1.png图片存入到数据库中.

public static void storePicBlog() throws FileNotFoundException, SQLException, IOException{

        Connection conn = JdbcUtil.getConnection();

        File f = new File("1.jpg");

        FileInputStream fis = new FileInputStream(f);

        

        String sql = "insert into pic_test(id,zp) values(?,?)";

        

        PreparedStatement ps = conn.prepareStatement(sql);

        

        ps.setString(1, StringUtil.getUUID());

        ps.setBinaryStream(2, fis, (int)f.length());

        

        ps.executeUpdate();

        

        fis.close();

        ps.close();

        JdbcUtil.release(conn);

    }

2:进行读取操作

public static InputStream getPicInputStream(){

        String id = "f304733361e243779b2340afe20e62bf";

        

         Connection conn = JdbcUtil.getConnection();

         

         PreparedStatement ps = null;

         

         ResultSet rs = null;

         

         InputStream is = null;

         

         String sql = "select zp from pic_test where id= ?";

         

        try {

            

            ps = conn.prepareStatement(sql);

            

            ps.setString(1, id);

            

            rs = ps.executeQuery();

            

            if(rs.next()){

                is = rs.getBlob("zp").getBinaryStream();

            }

            

        } catch (SQLException ex) {

            Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);

        }finally{

            try {

                if(null!=ps){

                    ps.close();

                }

            } catch (SQLException ex) {

                Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);

            }

            try {

                if(null!=rs){

                    rs.close();

                }

            } catch (SQLException ex) {

                Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);

            }

            JdbcUtil.release(conn);

        }

         

        

        return is;

    }

3:测试Servlet,通过浏览器访问此Servlet,一定要设置:

response.setContentType("image/jpeg");浏览器中才可以将图片显示出来

protected void processRequest(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        response.setContentType("image/jpeg");

        

        InputStream is = Test.getPicInputStream();

        

        if(null!=is){

           

            OutputStream os = response.getOutputStream();

            

            int len;

            

            byte buf[] = new byte[1024];

            

            while((len=is.read(buf))!=-1){

                os.write(buf, 0, len);

            }

            

            is.close();

            os.close();

        }

        

    }