Question

我正在尝试根据驻留在数据库中的信息创建PDF。知道我需要从Java检索作为BLOB存储在mysql数据库中的TIFF图像。我不知道该怎么做。我发现的示例显示了如何检索它并将其保存为文件（但在磁盘上），我需要驻留在内存中。

表名：IMAGENES_REGISTROS

BLOB字段名称：IMAGEN

任何想法？

Answer 1

在ResultSet来电：

Blob imageBlob = resultSet.getBlob(yourBlobColumnIndex);
InputStream binaryStream = imageBlob.getBinaryStream(0, imageBlob.length());

或者，您可以致电：

byte[] imageBytes = imageBlob.getBytes(1, (int) imageBlob.length());

正如BalusC在评论中指出的那样，你最好使用：

InputStream binaryStream = resultSet.getBinaryStream(yourBlobColumnIndex);

然后代码取决于您将如何阅读和嵌入图像。

Answer 2

final String dbURL = "jdbc:mysql://localhost:3306/portfolio";
    final String dbUser = "root";
    final String dbPass = "";

    Connection conn = null;
    Statement stmt = null;

    try {
        //DriverManager.registerDriver(new com.mysql.jdbc.Driver());
        Class.forName("com.mysql.jdbc.Driver");

        conn = DriverManager.getConnection(dbURL, dbUser, dbPass);
        System.out.println("db connected");
        stmt = (Statement) conn.createStatement();

        ResultSet rs1;
        rs1 = stmt.executeQuery("select profileImage from tbl_welcome where id = 1117");

        if (rs1.next()) {
            byte[] imgData = rs1.getBytes("profileImage");//Here....... r1.getBytes() extract byte data from resultSet 
            System.out.println(imgData);
            response.setHeader("expires", "0");
            response.setContentType("image/jpg");

            OutputStream os = response.getOutputStream(); // output with the help of outputStream 
            os.write(imgData);
            os.flush();
            os.close();

        }
    } catch (SQLException ex) {
        // String message = "ERROR: " + ex.getMessage();
        ex.printStackTrace();
    } finally {
        if (conn != null) {
            // closes the database connection
            try {
                conn.close();
            } catch (SQLException ex) {
                ex.printStackTrace();
            }
        }
    }

Answer 3

imagebytes = rs.getBytes("images");
image=getToolkit().createImage(imageBytes);
Image img = image.getScaledInstance(100,100,Image.SCALE_SMOOTH);
ImageIcon icon=new ImageIcon(img);
jLabel6.setIcon(icon);

尝试使用此代码从netbeans中的博客Mysql获取可调整图像

Answer 4

private void loadFileDataBlobFromDataBase()
             {
            List<Blob> bFile = jdbcTemplate.query(sql, new RowMapper<Blob>() {
                @Override
                public Blob mapRow(ResultSet rs, int rowNum)
                        throws SQLException {
                    return rs.getBlob(1);
                }
            });
            if (bFile != null && bFile.size() > 0) {
                bufReader = new BufferedReader(new InputStreamReader(bFile.get(
                        0).getBinaryStream()));
            }
            if (null != bufReader) {
                dataVO record = null;
                String lineStr = bufReader.readLine();
                record = (dataVO) lineMapper.mapLine(lineStr, 1);               
            }
        }
    }

检索在MYSQL DB上存储为BLOB的映像

4 个答案: