怎样把数据库里的图片路径读出来显示为图片？

简单的数据库 *** 作类

public class conn

{

public OleDbConnection con

public OleDbCommand command

public OleDbDataReader dr

public OleDbDataAdapter ada

public conn()

{

try

{

con = new OleDbConnection("provider=microsoft.jet.oledb.4.0data source="+System.Web.HttpContext.Current.Server.MapPath("你的数据库地址"))

con.Open()

}

catch (InvalidOperationException one)

{

System.Web.HttpContext.Current.Response.Write(one.Message)

return

}

catch (OleDbException two)

{

System.Web.HttpContext.Current.Response.Write(two.Message)

return

}

}

public void close()

{

con.Close()

}

public void cmd(string str,int m)

{

command = new OleDbCommand(str,con)

try

{

if(m==1)

{

command.ExecuteNonQuery()

}

else

{

dr = command.ExecuteReader()

}

}

catch(InvalidOperationException one)

{

System.Web.HttpContext.Current.Response.Write(one.Message)

return

}

}

public void da(string str)

{

ada = new OleDbDataAdapter(str,con)

}

}

///////////////////////////以下是 *** 作代码/////////////

conn con = new conn()打开数据库

con.cmd("select 数据库存放图片路径的字段 from 表 where 条件")

if(con.dr.Read())

Response.Write("<img src=\""+con.dr[0].ToString()+"\">")//输出图片

else

Response.Write("信息不存在")

con.close()//关闭数据库

给你提供个ACCESS版的VB代码，使用时调用这些过程即可：

'使用ADODB.Stream来保存/读取图像文件到数据库

'引用Microsoft ActiveX Data Objects 2.5 Library及以上版本

'保存文件到数据库中

Sub SaveFile()

Dim Stm As New ADODB.Stream

Dim Cnn As New ADODB.Connection

Dim rs As New ADODB.Recordset

Dim strCnn As String

strCnn = "Provider=Microsoft.Jet.OLEDB.4.0Persist Security Info=FalseData Source=" &_

App.Path &"\DB1.mdb"

Cnn.Open strCnn

'读取文件到内存(二进制模式)

With Stm

.Type = adTypeBinary

.Open

.LoadFromFile App.Path + "\Image1.bmp"

End With

With rs

.Open "SELECT * FROM TABLE1", Cnn, 1, 3

.AddNew

.Fields("IMAGE") = Stm.Read

.Update

End With

rs.Close

Stm.Close

Set rs = Nothing

Set Cnn = Nothing

Set Stm = Nothing

End Sub

'从数据库中读取图像文件

Sub ReadFile()

Dim Stm As New ADODB.Stream

Dim Cnn As New ADODB.Connection

Dim rs As New ADODB.Recordset

Dim strCnn As String

strCnn = "Provider=Microsoft.Jet.OLEDB.4.0Persist Security Info=FalseData Source=" &_

App.Path &"\DB1.mdb"

Cnn.Open strCnn

rs.Open "SELECT IMAGE FROM TABLE1 WHERE ID = 18", Cnn, adOpenKeyset, adLockReadOnly

'保存到文件

With Stm

.Mode = adModeReadWrite

.Type = adTypeBinary

.Open

.Write rs("IMAGE")

.SaveToFile App.Path + "\Image2.bmp"

End With

'显示图片

Picture1.Picture = LoadPicture(App.Path + "\Image2.bmp")

rs.Close

Stm.Close

Set rs = Nothing

Set Cnn = Nothing

Set Stm = Nothing

End Sub

我把你的代码稍微改造了下，我这边是可以显示图片的。代码如下：

数据库 *** 作部分：

package com.database

import java.io.InputStream

import java.sql.*

/**

 * @作者 王建明

 * @创建日期 13-10-7

 * @创建时间 下午12:32

 * @版本号 V 1.0

 */

public class DataBaseUtil {

public static InputStream getImageStreamFromDataBase() {

Connection conn = null

try {

Class.forName("com.mysql.jdbc.Driver")

conn =

DriverManager.getConnection("jdbc:mysql://localhost/quickstart", "root", "123456")

Statement stmt = conn.createStatement()

String sql = "select book_image from tbl_book where id=1 "

ResultSet rs = stmt.executeQuery(sql)

if (rs.next()) {

return rs.getBinaryStream("book_image")

}

} catch (Exception e) {

System.out.println("出现异常: " + e.getMessage())

} finally {

try {

if (conn != null)

conn.close()

} catch (SQLException e) {

e.printStackTrace()

}

}

return null

}

}

servlet部分：

package com.servlet

import com.database.DataBaseUtil

import javax.servlet.ServletException

import javax.servlet.http.HttpServlet

import javax.servlet.http.HttpServletRequest

import javax.servlet.http.HttpServletResponse

import java.io.IOException

import java.io.InputStream

import java.io.OutputStream

/**

 * @作者 王建明

 * @创建日期 13-10-7

 * @创建时间 下午12:18

 * @版本号 V 1.0

 */

public class ShowImage extends HttpServlet {

protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

doGet(request, response)

}

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

InputStream in = DataBaseUtil.getImageStreamFromDataBase()

OutputStream toClient = response.getOutputStream()

response.reset()

response.setContentType("image/jpg")//或gif

int len = 10*1024*1024

byte[] P_Buf = new byte[len]

int i

while((i = in.read(P_Buf)) != -1){

toClient.write(P_Buf, 0, i)

}

in.close()

toClient.flush()

toClient.close()

}

}

web.xml中的servlet配置：

    <servlet>

        <servlet-name>ShowImage</servlet-name>

        <servlet-class>com.servlet.ShowImage</servlet-class>

    </servlet>

    <servlet-mapping>

        <servlet-name>ShowImage</servlet-name>

        <url-pattern>/showImage</url-pattern>

    </servlet-mapping>

页面中加载图片方式：

<img src="showImage" />

希望对你有帮助O(∩_∩)O~

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