web应用中把上传文件保存到数据库的优点

web应用中把上传文件保存到数据库的优点是方便管理。

性能不会损耗太大，速度也比其他数据库快，且专门存储电影、图片等内容。

据说香港的马会录象全部是存储的。

把上传的照片存到服务器下并把路径存入数据库，读取时使用File对象根据数据库内存储的照片路径读取照片。注意from表单的这两个属性enctype="multipart/from-data" method="post"

<package name="fileupload" extends="webwork-default">

<interceptors>

<interceptor name="fileUpload"

class="com.opensymphony.webwork.interceptor.FileUploadInterceptor">

<param name="allowedTypes">image/jpeg/jpg/bmp</param>

<param name="maximumSize">10000000</param>

</interceptor> <interceptor-stack name="fileUploadStack">

<interceptor-ref name="fileUpload" />

<interceptor-ref name="defaultStack" />

</interceptor-stack><default-interceptor-ref name="fileUploadStack" /> </package > /**

* 上传照片方法

*/

public void fk_upload(String customer_no, File photo) {

long sta = System.currentTimeMillis()

Connection conn = null

PreparedStatement pstmt = null

FileInputStream fis = null

try {

conn = getConnection()

conn.setAutoCommit(false)

String strSQL = "UPDATE CARD_BASEINFO SET PHOTO=? WHERE CUSTOMER_NO=?"

fis = new FileInputStream(photo)

pstmt = conn.prepareStatement(strSQL)

pstmt.setBinaryStream(1, fis, fis.available())

pstmt.setString(2, customer_no)

int i = pstmt.executeUpdate()

System.out.println("=========>" + i)

conn.commit()

} catch (Exception ex) {

try {

conn.rollback()

} catch (SQLException e) {

System.out.println("回滚也异常")

}

ex.printStackTrace()

} finally {

try {

if (null != fis) {

fis.close()

}

if (null != pstmt) {

pstmt.close()

}

if (null != conn) {

conn.close()

}

} catch (Exception ex) {

System.out.println("偶也！关闭数据源出错了！")

ex.printStackTrace()

}

long end = System.currentTimeMillis() double useTime = BigDecimal.valueOf((end - sta)).divide(

BigDecimal.valueOf(1000)).setScale(2,

BigDecimal.ROUND_HALF_UP).doubleValue()

System.out.println("执行DAO时间为：" + useTime + "秒")

}

}

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