Java从Oracle读取Blob显示图片在页面

一。jsp页面

<image src="/foi/obstacleReport/image" onload="if(this.width>screen.width-1000)this.style.width=screen.width-1000;"/>

二。后台

1。.得到数据库连接。

def dbDriver = "oracle.jdbc.driver.OracleDriver";

def url = "jdbc:oracle:thinxx

def username = "foi";

def password = "foi";

Connection conn = null;

Class.forName(dbDriver);

DriverManager.setLoginTimeout(30);

conn = DriverManager.getConnection(url, username, password);

2 。写sql语句

def query ="""select photo from photo_list where id = 1"""

3 。预编译

byte[] description = "";

def pstmt = conn.prepareStatement(query);

ResultSet result = pstmt.executeQuery();

StringBuffer myStringBuffer = new StringBuffer();

if (result.next()) {

java.sql.Blob blob = result.getBlob("photo");

InputStream inStream = blob.getBinaryStream();

long nLen = blob.length();

int nSize = (int) nLen;

description = new byte[nSize];

inStream.read(description);

inStream.close();

description = ChangeImgSize(description, 200, 200);

if(description!=null){

OutputStream op = response.getOutputStream();

op.write(description, 0, description.length);

op.close();

op = null;

}

response.flushBuffer();

}

result.close();

pstmt.close();

conn.close();

}

}

private byte[] ChangeImgSize(byte[] data, int nw, int nh){

byte[] newdata = null;

try{

BufferedImage bis = ImageIO.read(new ByteArrayInputStream(data));

if(bis!=null){

int w = bis.getWidth();

int h = bis.getHeight();

double sx = (double) nw / w;

double sy = (double) nh / h;

AffineTransform transform = new AffineTransform();

transform.setToScale(sx, sy);

//AffineTransformOp ato = new AffineTransformOp(transform, null);

//原始颜色

//BufferedImage bid = new BufferedImage(nw, nh, BufferedImage.TYPE_3BYTE_BGR);

//ato.filter(bis, bid);

//转换成byte字节

ByteArrayOutputStream baos = new ByteArrayOutputStream();

ImageIO.write(bis, "jpeg", baos);

newdata = baos.toByteArray();

}

}catch(IOException e){

e.printStackTrace();

}

return newdata;

}