![将BufferedInputStream转换为图像[重复]](http://www.mshxw.com/aiimages/31/402719.png "将BufferedInputStream转换为图像[重复]")
首先，先确认
uploadedInputStream是有效图像，然后再使用将其写出来
ImageIO.write。您始终可以使用
ImageIO.read读回的图像并将其写回到
ByteArrayInputStream;）
我使用H2数据库进行了快速测试。
我注意到了几件事。
Blob#length返回
long，而
Blob#getBytes期望则返回
int，这可能意味着您正在截断字节流。
另外，从H2的文档来看，似乎
Blob内容没有保存在内存中，因此我改用了
getBinaryStream。
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) { } } }}
