Question

我想要一个以二进制流的形式上传图片到数据库还可以从数据库中取出图片 我找了好久 看到你写出来了能借鉴

不好意思 我想要JSP的 不过 谢谢

Answer 1

哥项目里面有，我改成大白话，你自己看看吧~！

SSH

1、在页面里面要有一个file
2、获取这个file，以blob形式存入数据库
3、读取blob输出到页面就可以了

<input type="file" 其他属性忽略 />

FormFile file0 = addForm.getSignfile();(这里用的是struts)

下面是用hibernate存数据，JDBC一样的用，去掉hibernate 而已

if(file0.getFileSize()!=0){
int titleSize=file0.getFileSize();
int t=10*1048576;
//if(titleSize>t){
//return mapping.findForward("f");
//}

Session s = HibernateUtil.getSessionFactory().openSession();
try {
s.beginTransaction();

String hql="From TsUserSign Where userid="+userid;
List list=s.createQuery(hql).list();
TsUserSign tsUserSign=new TsUserSign();
if (list.size()>0)
tsUserSign=(TsUserSign)list.get(0);

tsUserSign.setUserid(userid);
tsUserSign.setSignbody(Hibernate.createBlob(new byte[1]));
s.saveOrUpdate(tsUserSign);
s.flush();
s.refresh(tsUserSign, LockMode.UPGRADE);
SerializableBlob body = (SerializableBlob) tsUserSign.getSignbody();
Blob body1 = body.getWrappedBlob();
BLOB body2 = (BLOB) body1;
//OutputStream out = body2.getBinaryOutputStream();
OutputStream out =body2.setBinaryStream(1L);
InputStream is = file0.getInputStream();
int readSize = 0;
byte[] buffer = new byte[1024];
while ((readSize = is.read(buffer, 0, 1024)) != -1) {
out.write(buffer, 0, readSize);
}
is.close();
out.close();
s.saveOrUpdate(tsUserSign);
s.flush();
s.getTransaction().commit();

} catch (RuntimeException e) {
// TODO Auto-generated catch block
e.printStackTrace();
s.getTransaction().rollback();
throw new Exception("手写签名文件保存失败!");
}
finally
{
s.close();
}
}

从Blob body1 = body.getWrappedBlob();这边开始，读与存其实都是一样的。。。你自己改改

Answer 2

不知道你问的是哪个语言，给你提供一下 。net 方法

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;

public partial class niunantest : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

}
protected void Button1_Click(object sender, EventArgs e)
{
string str = FileUpload1.PostedFile.ContentType;
Response.Write("文件类型："+str);

string filename = "";

FileExtension[] fe = { FileExtension.GIF, FileExtension.JPG, FileExtension.PNG };
if (FileValidation.IsAllowedExtension(FileUpload1, fe))
{
string fileExt = System.IO.Path.GetExtension(FileUpload1.FileName).ToLower();
Response.Write("<br>验证通过！");
//filename = "/Images/" + DateTime.Now.ToString("yyyyMMddHHmmss") + fileExt;
//FileUpload1.PostedFile.SaveAs(Server.MapPath(filename));
}
else
{
Response.Write( "<br>验证不通过，只支持以下格式的图片：JPG,GIF,PNG");
return;
}

}

public enum FileExtension
{
JPG = 255216,
GIF = 7173,
PNG = 13780,
SWF = 6787,
RAR = 8297,
ZIP = 8075,
_7Z = 55122

// 255216 jpg;

// 7173 gif;

// 6677 bmp,

// 13780 png;

// 6787 swf

// 7790 exe dll,

// 8297 rar

// 8075 zip

// 55122 7z

// 6063 xml

// 6033 html

// 239187 aspx

// 117115 cs

// 119105 js

// 102100 txt

// 255254 sql

}

public class FileValidation
{
public static bool IsAllowedExtension(FileUpload fu, FileExtension[] fileEx)
{
int fileLen = fu.PostedFile.ContentLength;
byte[] imgArray = new byte[fileLen];
fu.PostedFile.InputStream.Read(imgArray, 0, fileLen);
MemoryStream ms = new MemoryStream(imgArray);
System.IO.BinaryReader br = new System.IO.BinaryReader(ms);
string fileclass = "";
byte buffer;
try
{
buffer = br.ReadByte();
fileclass = buffer.ToString();
buffer = br.ReadByte();
fileclass += buffer.ToString();
}
catch
{
}
br.Close();
ms.Close();
foreach (FileExtension fe in fileEx)
{
if (Int32.Parse(fileclass) == (int)fe)
return true;
}
return false;
}
}
}