struts保存图片到数据库 ，从数据库中读取图片显示到页面

1、数据结构:

CREATE TABLE [photo] (
[id] [int] IDENTITY (1, 1) NOT NULL ,
[ordernumber] [nvarchar] (20)[photo] [image] NULL ,
PRIMARY KEY CLUSTERED
(
[id]
) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]

2、整体架构:struts2+spring2+hibernate3

3、vo结构:

public class Photo implements Serializable
{
private int id;
private String ordernum;
private byte[] photo;

......省get(),set()方法

}

4、数据存取DAO:

public interface PhotoDao
{
public void savePhoto(Photo photo);
public Photo getPhoto(String ordername);
}

5、实现

public class PhotoDaoHibernate extends HibernateDaoSupport implements PhotoDao
{

@Override
public Photo getPhoto(String ordername)
{
List list=this.getHibernateTemplate().find("from Photo where ordernum=?",ordername);
System.out.println("listsize"+list.size()+";filename:"+ordername);
if(list.size()>0)
{

return (Photo)list.get(0);
}
else
{
return null;
}
}

@Override
public void savePhoto(Photo photo)
{
this.getHibernateTemplate().save(photo);

}

}

5、上传Action

public class UpLoadPhoto extends ActionSupport
{
private PhotoDao pdi;//pdi为通过spring注入的Dao实例，用于把Photo对象存入数据库
private String filename;
private File upload;
private InputStream inputStream;
public void setInputStream(InputStream inputStream)
{
this.inputStream = inputStream;
}
public String upload()
{
if(filename!=null && !"".equals(filename))
{
Photo photo=new Photo();
photo.setOrdernum(filename);
photo.setPhoto(getBytesFromFile(upload));
System.out.println(photo.getOrdernum()+photo.getPhoto());
pdi.savePhoto(photo);
}
return SUCCESS;
}
public static byte[] getBytesFromFile( File file ) {

long length = file.length();
byte[] bytes = new byte[(int)length];

try {
InputStream is = new FileInputStream(file);

// Read in the bytes
int offset = 0;
int numRead = 0;
while (offset < bytes.length
&& (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0) {
offset += numRead;
}

// Ensure all the bytes have been read in
if (offset < bytes.length) {
throw new IOException("Could not completely read file "+file.getName());
}

// Close the input stream and return bytes
is.close();
} catch(Exception e ) {
throw new RuntimeException(e);
}
return bytes;
}

}

*/
public PhotoDao getPdi()
{
return pdi;
}
public void setPdi(PhotoDao pdi)
{
this.pdi = pdi;
}
public String getFilename()
{
return filename;
}
public void setFilename(String filename)
{
this.filename = filename;
}
public File getUpload()
{
return upload;
}
public void setUpload(File upload)
{
this.upload = upload;
}

}

6、jsp上传

<s:form action="uploadfile" method="post" enctype="multipart/form-data">
<s:file name="upload"/>
文件名:<s:textfield name="filename"/>
<s:submit value="图片上传"></s:submit>
</s:form>

7、用于从数居库显示图片的Action

public class ShowPhoto extends ActionSupport
{
private PhotoDao pdi;
private String filename;
public String getFilename()
{
return filename;
}

public void setFilename(String filename)
{
this.filename = filename;
}

public PhotoDao getPdi()
{
return pdi;
}

public void setPdi(PhotoDao pdi)
{
this.pdi = pdi;
}

@Override
public String execute() throws Exception
{
// TODO Auto-generated method stub
return SUCCESS;
}
public InputStream getInputStream()
{

Photo photo=new Photo();
try
{
photo=pdi.getPhoto(filename);

} catch (RuntimeException e)
{
e.printStackTrace();
}
if(photo==null||photo.getPhoto()==null)
{
return null;
}
else
{
System.out.println(photo.getOrdernum());
System.out.println(photo.getPhoto());
System.out.println("Image_Lenghth:"+photo.getPhoto().length);
ByteArrayInputStream bais;
try
{
bais = new ByteArrayInputStream(photo.getPhoto());
return bais;
} catch (RuntimeException e)
{
e.printStackTrace();
return null;
}

}
}

}

8、jsp中显示图片

<s:url id="image" action="getPhoto?filename=ck" /><!--ck为数据库中查找图片的关键字(上传时设的文件名)-->
<img src="<s:property value="#image"/>"/>

9、struts.xml配置

<action name="uploadfile" class="uploadfile" method="upload"><!-- 指定逻辑方法method -->
<result name="success">/success.jsp</result>
</action>
<action name="getPhoto" class="getPhoto" >
<result name="success" type="stream">
<param name="contentType">image/jpeg</param>
<param name="inputName">inputStream</param>
<param name="contentDisposition">attachment;filename="s.jpg"</param><!--指定默认文件名-->
<param name="bufferSize">1024</param>><!--指定缓存大小-->
</result>
</action>