Zacznij od sprawdzenia, czy uploadedInputStream jest prawidłowym obrazem, najprawdopodobniej zapisując go za pomocą ImageIO.write . Zawsze możesz użyć ImageIO.read aby ponownie wczytać obraz i zapisać go z powrotem w ByteArrayInputStream;)
Zrobiłem szybki test przy użyciu bazy danych H2.
Kilka rzeczy, które zauważyłem. Blob#length zwraca long , natomiast Blob#getBytes oczekuje int , może to oznaczać, że obcinasz strumień bajtów.
Również z dokumentacji H2 wynika, że Blob zawartość nie jest przechowywana w pamięci, więc używam getBinaryStream zamiast tego.
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.sql.Blob;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
public class TestImageDatbase {
private Connection con;
public static void main(String[] args) {
new TestImageDatbase();
}
public TestImageDatbase() {
try {
clearDatabase();
saveImage();
loadImage();
} catch (ClassNotFoundException | SQLException | IOException exp) {
exp.printStackTrace();
}
}
protected Connection getConnection() throws ClassNotFoundException, SQLException {
Class.forName("org.h2.Driver");
return DriverManager.getConnection("jdbc:h2:d:\\Image", "sa", "");
}
protected void clearDatabase() throws IOException, ClassNotFoundException, SQLException {
Connection con = null;
PreparedStatement stmt = null;
try {
con = getConnection();
System.out.println("Cleaning database");
stmt = con.prepareStatement("delete from images");
int updated = stmt.executeUpdate();
System.out.println("Updated " + updated + " rows");
} finally {
try {
stmt.close();
} catch (Exception e) {
}
try {
con.close();
} catch (Exception e) {
}
}
}
protected void saveImage() throws IOException, ClassNotFoundException, SQLException {
Connection con = null;
PreparedStatement stmt = null;
ByteArrayOutputStream baos = null;
ByteArrayInputStream bais = null;
try {
baos = new ByteArrayOutputStream();
File source = new File("/path/to/file");
System.out.println("Source size = " + source.length());
BufferedImage img = ImageIO.read(source);
ImageIO.write(img, "png", baos);
baos.close();
bais = new ByteArrayInputStream(baos.toByteArray());
con = getConnection();
stmt = con.prepareStatement("insert into images (image) values (?)");
stmt.setBinaryStream(1, bais);
int updated = stmt.executeUpdate();
System.out.println("Updated " + updated + " rows");
} finally {
try {
bais.close();
} catch (Exception e) {
}
try {
baos.close();
} catch (Exception e) {
}
try {
stmt.close();
} catch (Exception e) {
}
try {
con.close();
} catch (Exception e) {
}
}
}
protected void loadImage() throws IOException, ClassNotFoundException, SQLException {
Connection con = null;
PreparedStatement stmt = null;
ResultSet rs = null;
try {
con = getConnection();
stmt = con.prepareStatement("select image from images");
rs = stmt.executeQuery();
while (rs.next()) {
System.out.println("Getting blob");
Blob blob = rs.getBlob(1);
System.out.println("Reading image");
BufferedImage img = ImageIO.read(blob.getBinaryStream());
System.out.println("img = " + img);
JOptionPane.showMessageDialog(null, new JScrollPane(new JLabel(new ImageIcon(img))));
}
} finally {
try {
rs.close();
} catch (Exception e) {
}
try {
stmt.close();
} catch (Exception e) {
}
try {
con.close();
} catch (Exception e) {
}
}
}
}
