java读写oracle的blob字段示例

package com.wanmei.meishu;

import java.io.fileinputstream;
import java.io.fileoutputstream;
import java.io.filereader;
import java.io.inputstream;
import java.io.outputstream;
import java.sql.connection;
import java.sql.drivermanager;
import java.sql.preparedstatement;
import java.sql.resultset;
import java.sql.sqlexception;
import java.util.properties;

import oracle.sql.blob;

public class blobutil {

 private static blobutil bu;
 private string env;
 public static blobutil getinstance(string env) {
  bu = new blobutil();
  bu.env = env;
  return bu;
 }

 /**
  * <p>得到数据库链接</p>
  * @return
  * @throws exception
  */
 private connection getconnection() throws exception {
  string driver = "oracle.jdbc.driver.oracledriver";
  class.forname(driver);
  string env = this.env;
  properties pro = new properties();
  // 读取classes 目录下的配置文件  
  pro.load(new filereader(class.class.getresource("/config.properties").getfile()));
  string host = pro.getproperty(env + ".host");
  string database = pro.getproperty(env + ".database");
  string username = pro.getproperty(env + ".username");
  string password = pro.getproperty(env + ".password");
  string port = pro.getproperty(env + ".port");
  string url = "jdbc:oracle:thin:@" + host + ":" + port +":" + database;
  return drivermanager.getconnection(url, username, password);
 }

 /**
  * <p>传入项目，任务，附件名称，文件路径，写入数据库</p>
  * @param projectid
  * @param taskid
  * @param filename
  * @param file
  * @return 返回是否成功
  */
 public boolean write(string projectid, string taskid, string filename, string file) {
  connection conn = null;
  resultset rs = null;
  preparedstatement ps = null;
  blob blob = null;
  boolean flag = false;
  try {
   conn = getconnection();
   conn.setautocommit(false);

   string sql = "insert into ps_zp_prj_wbs_blob blb(zp_prj_id, zz_seq_num, zz_file_name, zz_image_blob) values(?, ? ,? ,empty_blob())";
   ps = conn.preparestatement(sql);
   ps.setstring(1, projectid);
   ps.setstring(2, taskid);
   ps.setstring(3, filename);
   ps.executeupdate();
   sql = "select zz_image_blob from ps_zp_prj_wbs_blob where zp_prj_id = ? and zz_seq_num = ? and zz_file_name = ? for update";
   ps = conn.preparestatement(sql);
   ps.setstring(1, projectid);
   ps.setstring(2, taskid);
   ps.setstring(3, filename);
   rs = ps.executequery();
   if(rs.next()) {
    blob = (blob) rs.getblob(1);
   }
   inputstream in = new fileinputstream(file);
   outputstream out = blob.setbinarystream(1l);
   byte[] buffer = new byte[1024];
   int length = -1;
            while ((length = in.read(buffer)) != -1){
                out.write(buffer, 0, length);
            }
            in.close();
            out.close();
            conn.commit();
            conn.setautocommit(true);
            flag = true; 
  }
  catch(exception e) {
   if(conn != null) {
    try {
     conn.rollback();
    } catch (sqlexception e1) {
     e1.printstacktrace();
    }
   }
  }
  finally {
   try {
    rs.close();
    ps.close();
    conn.close();
   }
   catch(exception e) {
    e.printstacktrace();
   }
  }
  return flag;
 }

 /**
  * <p>根据项目id，任务id，文件名读取数据库blob字段文件，写入指定的文件路径</p>
  * @param projectid
  * @param taskid
  * @param filename
  * @param file
  * @return 返回是否成功
  */
 public boolean read(string projectid, string taskid, string filename, string file) {
  connection conn = null;
  resultset rs = null;
  preparedstatement ps = null;
  blob blob = null;
  boolean flag = false;
  try {
   conn = getconnection();
   string sql = "select zz_image_blob from ps_zp_prj_wbs_blob where zp_prj_id = ? and zz_seq_num = ? and zz_file_name = ?";
   ps = conn.preparestatement(sql);
   ps.setstring(1, projectid);
   ps.setstring(2, taskid);
   ps.setstring(3, filename);
   rs = ps.executequery();
   if(rs.next()) {
    blob = (blob) rs.getblob(1);
   }
   inputstream in = blob.getbinarystream();
   byte[] buf = new byte[1024];
   int bytesin = 0;
   fileoutputstream out = new fileoutputstream(file);
   while ((bytesin = in.read(buf, 0, 1024)) != -1) {
    out.write(buf, 0, bytesin);
   }
            in.close();
            out.close();
            flag = true;
  }
  catch(exception e) {
   e.printstacktrace();
  }
  finally {
   try {
    rs.close();
    ps.close();
    conn.close();
   }
   catch(exception e) {
    e.printstacktrace();
   }
  }
  return flag;
 }

 public static void main(string[] args) {
  blobutil bu = blobutil.getinstance("msdev");
  system.out.println(bu.write("cb", "001", "image1", "d:\\61e44b02jw1dw4xbp2zo6j.jpg"));
  system.out.println(bu.read("cb", "001", "image1", "d:\\2.jpg"));
 }

}