《--------保存图片到数据库--------------》
public void savePic(InputStream is){
String insertsql = "insert into pic(id,pic) values(1,empty_blob())";
Connection conn = null;
Statement stmt = null;
PreparedStatement ps = null;
ResultSet rs = null;
try {
conn = ds.getConnection();
conn.setAutoCommit(false);
stmt = conn.createStatement();
int rt = stmt.executeUpdate(insertsql);
if(rt > 0){
System.out.println("initialization succeed!!");
String preCursor = "select id,pic from pic where id='1' for update";
rs = stmt.executeQuery(preCursor);
rs.next();
Blob b = (Blob)rs.getBlob("pic");
BufferedOutputStream bos = new BufferedOutputStream(b.setBinaryStream(0L));
BufferedInputStream bis = new BufferedInputStream(is);
int bytes;
try {
while((bytes = bis.read()) != -1){
bos.write(bytes);
}

bis.close();
bos.close();
conn.commit();
} catch (IOException e) {
e.printStackTrace();
}
}

} catch (SQLException e) {
e.printStackTrace();
} finally{
try {
rs.close();
stmt.close();
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}


《--------获取图片到到页面--------------》
public JPEGImageEncoder getPic(String id,HttpServletResponse res) throws IOException{
Connection conn = null;
Statement stmt = null;
PreparedStatement ps = null;
ResultSet rs = null;
BufferedInputStream imageStream = null;
BufferedImage image = null;
JPEGImageEncoder encoder = null;
ServletOutputStream sos = res.getOutputStream();
try {
conn = ds.getConnection();
conn.setAutoCommit(false);
stmt = conn.createStatement();
System.out.println("initialization succeed!!");
String preCursor = "select id,pic from pic where id='1'";
rs = stmt.executeQuery(preCursor);
rs.next();
imageStream = new BufferedInputStream(((Blob)rs.getBlob(2)).getBinaryStream());
try {
image = ImageIO.read(imageStream);
encoder = JPEGCodec.createJPEGEncoder(sos);
encoder.encode(image);
imageStream.close();
} catch (IOException e) {
e.printStackTrace();
}

} catch (SQLException e) {
e.printStackTrace();
} finally{
try {
rs.close();
stmt.close();
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
return encoder;
} 从数据库获取图片，导出到本地的完整代码： package dbcon;

import java.awt.image.BufferedImage;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
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 java.sql.Statement;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;

import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

public class DBManager {
private String url = "jdbc:oracle:thin:@10.23.65.21:1521:orcl";
private String userName = "test";
private String password = "test";
private String driver = "oracle.jdbc.driver.OracleDriver";
private Connection conn;


public DBManager(){
try {
Class.forName(driver);
conn = DriverManager.getConnection(url, userName, password);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
}

public void getPic(String picPath) throws IOException{
Statement stmt = null;
PreparedStatement ps = null;
ResultSet rs = null;
BufferedInputStream imageStream = null;
BufferedImage image = null;
JPEGImageEncoder encoder = null;
try {
conn.setAutoCommit(false);
stmt = conn.createStatement();
System.out.println("initialization succeed!!");
String preCursor = "select id,zp from zpb where id='2220087'";
rs = stmt.executeQuery(preCursor);
while(rs.next()){
imageStream = new BufferedInputStream(((Blob)rs.getBlob(2)).getBinaryStream());
try {
String id = rs.getString(1);
File picturePath = new File(picPath +"/"+ id +".jpg");
boolean created = false;
if(!picturePath.exists()){
created = picturePath.createNewFile();
} else {
created = true;
}
if(created){
// ServletOutputStream sos = res.getOutputStream();
OutputStream ostream = new FileOutputStream(picturePath);
image = ImageIO.read(imageStream);
encoder = JPEGCodec.createJPEGEncoder(ostream);
encoder.encode(image);
imageStream.close();
ostream.flush();
ostream.close();
}
} catch (IOException e) {
e.printStackTrace();
}
}

} catch (SQLException e) {
e.printStackTrace();
} finally{
try {
rs.close();
stmt.close();
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}


public static void main(String[] s){
DBManager manager = new DBManager();
String localPath = "E:/testpics";
try {
manager.getPic(localPath);
} catch (IOException e) {
e.printStackTrace();
}
}

}