Java 访问mysql的blob,对图片进行存取

此实现为用java访问mysql的blob,对图片进行存取

 

/** * Title:         BlobPros.java * Project:       test * Description:  把图片存入mysql中的blob字段，并取出 * Call Module:  mtools数据库中的tmp表 * File:         C:downloadsluozsh.jpg * Copyright: Copyright (c) 2003-2003 * Company:      uniware * Create Date:  2002.12.5 * @Author:      ChenQH * @version 1.0 版本* * *  Revision history *  Name         Date     Description *  ----      ----        ----------- * Chenqh   2003.12.5        对图片进行存取 * * note:         要把数据库中的Blob字段设为longblob * *///package com.uniware;import java.io.*; import java.util.*; import java.sql.*;public class BlobPros { private static final String URL = "jdbc:mysql://10.144.123.63:3306/mtools?user=wind&password=123&useUnicode=true"; private Connection conn = null; private PreparedStatement pstmt = null; private ResultSet rs = null; private File file = null;public BlobPros() { }/** * 向数据库中插入一个新的BLOB对象(图片) * @param infile 要输入的数据文件 * @throws java.lang.Exception */ public void blobInsert(String infile) throws Exception { FileInputStream fis = null; try { Class.forName("org.gjt.mm.mysql.Driver").newInstance(); conn = DriverManager.getConnection(URL);file = new File(infile); fis = new FileInputStream(file); //InputStream fis = new FileInputStream(infile); pstmt = conn.prepareStatement("insert into tmp(descs,pic) values(?,?)"); pstmt.setString(1,file.getName());    //把传过来的第一个参数设为文件名 //pstmt.setBinaryStream(2,fis,(int)file.length());   //这种方法原理上会丢数据，因为file.length()返回的是long型 pstmt.setBinaryStream(2,fis,fis.available());  //第二个参数为文件的内容 pstmt.executeUpdate(); } catch(Exception ex) { System.out.println("[blobInsert error : ]" + ex.toString()); } finally { //关闭所打开的对像// pstmt.close(); fis.close(); conn.close(); } }/** * 从数据库中读出BLOB对象 * @param outfile 输出的数据文件 * @param picID 要取的图片在数据库中的ID * @throws java.lang.Exception */public void blobRead(String outfile,int picID) throws Exception { FileOutputStream fos = null; InputStream is = null; byte[] Buffer = new byte[4096];try { Class.forName("org.gjt.mm.mysql.Driver").newInstance(); conn = DriverManager.getConnection(URL); pstmt = conn.prepareStatement("select pic from tmp where id=?"); pstmt.setInt(1,picID);         //传入要取的图片的ID rs = pstmt.executeQuery(); rs.next();file = new File(outfile); if(!file.exists()) { file.createNewFile();     //如果文件不存在，则创建 } fos = new FileOutputStream(file); is = rs.getBinaryStream("pic"); int size = 0; /* while(size != -1) { size = is.read(Buffer);    //从数据库中一段一段的读出数据 //System.out.println(size); if(size != -1)            //-1表示读到了文件末 fos.write(Buffer,0,size); }  */ while((size = is.read(Buffer)) != -1) { //System.out.println(size); fos.write(Buffer,0,size); }} catch(Exception e) { System.out.println("[OutPutFile error : ]" + e.getMessage()); } finally { //关闭用到的资源 fos.close(); rs.close(); pstmt.close(); conn.close(); } }public static void main(String[] args) { try {BlobPros blob = new BlobPros(); //blob.blobInsert("C:Downloadsluozsh1.jpg"); blob.blobRead("c:/downloads/1.jpg",47); } catch(Exception e) { System.out.println("[Main func error: ]" + e.getMessage()); } } }

 参考资料：http://www.cublog.cn/u/2550/?u=http://www.cublog.cn/u/2550/showart.php?id=9900