2014 再出发: 2007年4月12日星期四

昨天干啥了？呵呵，昨天没过来写，哈哈现在是周五了，噢对，哈哈，昨天有活干了，让我做一个上传图片，把图片报存在数据库中，然后再读出来显示，要能查询、添加、删除。好了动手吧，以前做过一个上传图片，但是不是把图片报存在数据库中，大同小异了。把关键代码贴在这里，供以后参考。

-----------------------------上传页面---------------------------------------------------------------
<%@page contentType="text/html; charset=gb2312" %>
<%@ taglib uri="/WEB-INF/struts-html" prefix="html"%>

<html>
    <head>
        <title>上传图片</title>
    </head>

<body>
    <h2>选择图片(JPEG格式, 大小小于1M)</h2>
    <br>

    <html:form action="/upload.do" enctype="multipart/form-data">
        <html:errors/>
        <table>
        <tr>
            <TD><html:file property="file" size="50"></html:file></TD>
        </tr>
        <TR height="20" valign="top" topmargin="0">
            <TD>备注:</TD>
        </tr>
        <tr>
            <TD><html:textarea rows="3" cols="40" property="memo"></html:textarea></TD>
        </TR>
        <tr>
            <tr height="20">
        </tr>
        <tr>
            <TD height="22" align="center">
        <html:submit> 上  传 </html: submit>      <input type="button" value=" 取  消 " onclick="window.close()"/></TD>
        </tr>

        </table>
    </html:form>
</body>

</html>

--------------------------------------action--UploadAction-----------------------------------------------------

public ActionForward execute(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response) throws Exception {

        response.setCharacterEncoding("gb2312"); //如果不设置，弹出的提示框是乱码

        UploadForm uploadForm = (UploadForm) form;
        FormFile file = uploadForm.getFile();
        String memo = uploadForm.getMemo();

        String fileName = file.getFileName();
        int length = file.getFileSize();

        InputStream imgStream = null;

        ActionMessages msgs = new ActionMessages();
        //向数据库插入记录
        try {
            imgStream = file.getInputStream();
            UserImg newUserImg = new UserImg();
            newUserImg.setImg(imgStream);
            newUserImg.setImgName(fileName);
            newUserImg.setMemo(memo);
            newUserImg.setFileSize(length);

            if(UploadImageDao.getInstance().insertImg(newUserImg))
            {
                response.getWriter().write(
                        CSScript.alertAndCloseScript(MessageKey.IMAGE_UPLOAD_SUCCESS));
                return null;
            }
            else
            {
                msgs.add(ActionMessages.GLOBAL_MESSAGE, new ActionMessage(
                        MessageKey.IMAGE_UPLOAD_FAILED));
                saveErrors(request, msgs);
            }
        } catch (IOException e) {

            msgs.add(ActionMessages.GLOBAL_MESSAGE, new ActionMessage(
                    MessageKey.IMAGE_UPLOAD_FAILED));
            saveErrors(request, msgs);

        } finally {
            try {
                if (imgStream != null)
                    imgStream.close();

            } catch (Exception e) {
                //do nothing here
            }
        }
        return mapping.getInputForward();


    }

--------------------------------------弹出提示框的类----------------------------------------------------------

public final class CSScript {
    private static final String S_OPEN = "<script>";
    private static final String S_CLOSE = "</script>";

    public static String alertAndCloseScript(String alert)
    {
        StringBuffer sb = new StringBuffer(S_OPEN);
        sb.append("alert('").append(alert).append("!');");
        sb.append("window.close();");
        sb.append("window.opener.document.location.reload();");
        sb.append(S_CLOSE);

        return sb.toString();
    }

    public static String errorScript(String err)
    {
        StringBuffer sb = new StringBuffer(S_OPEN);
        sb.append("alert('").append(err).append("!');");
        sb.append(S_CLOSE);

        return sb.toString();
    }

    public static String alertScript(String alert)
    {
        StringBuffer sb = new StringBuffer(S_OPEN);
        sb.append("alert('").append(alert).append("!');");
        sb.append(S_CLOSE);

        return sb.toString();
    }
}

---------------------------------------插入数据库的方法-----------------------------------------------------
public boolean insertImg(UserImg userImg)
    {
        Session session = HibernateSessionFactory.getSession();
        Transaction tran = session.beginTransaction();
        try
        {
            Connection conn = session.connection();
            PreparedStatement psta = conn.prepareStatement("insert into userImg values(?,?,?)");
            psta.setString(1,userImg.getImgName());
            psta.setBinaryStream(2, userImg.getImg(),userImg.getFileSize());
            psta.setString(3, userImg.getMemo());
            psta.execute();

            tran.commit();
        }
        catch(Exception e)
        {
            e.printStackTrace();
            tran.rollback();
            return false;
        }
        finally
        {
            HibernateSessionFactory.closeSession();
        }
        return true;
    }
注意，这里可以看到涌到了hibernate的session，但还是用的jdbc插入数据库，是因为hibernate对image类型的字段支持不好。

-----------------------------------------读取图片的action-getImg.do-----------------------------------------------------------

public ActionForward execute(ActionMapping mapping, ActionForm form,
            HttpServletRequest request, HttpServletResponse response) {
        int id = Integer.parseInt(request.getParameter("id"));
        InputStream inStream = UploadImageDao.getInstance().getImg(id);

        response.setContentType("image/pjpeg");
        try {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            byte[] buffer = new byte[1024];
            int bytesRead = 0;
            while ((bytesRead = inStream.read(buffer, 0, 1024)) != -1) {
                baos.write(buffer, 0, bytesRead);
            }
            OutputStream outs = response.getOutputStream();

            outs.write(baos.toByteArray());

            outs.flush();

            inStream.close();
            baos.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

页面中显示图片，这么写
<img width="100" height="100" src="getImg.do?id=<bean:write name="list" property="id"/>" />

2014 再出发

2007年4月13日星期五

2007年4月12日星期四

2 条评论:

2007年4月13日星期五

2007年4月12日 星期四

2 条评论:

2007年4月12日星期四