acceptbookimgtag.java

一个简单的购物网站,包括购物车的实现

package csai.tag;
import java.io.FileInputStream;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;

import javax.naming.Context;
import javax.naming.InitialContext;
import javax.servlet.jsp.tagext.TagSupport;
import javax.sql.DataSource;

import com.jspsmart.upload.SmartUpload;
/**
 * @author dengziyun
 * 接收上传的图片的标签处理类
 */
public class acceptBookImgTag extends TagSupport{
	//----标签开始时调用此方法-------
	public int doStartTag(){
		//新建一个SmartUpload对象
		SmartUpload su = new SmartUpload();
		try {
			//上传初始化
			su.initialize(pageContext);
			//设定允许上传的文件（通过扩展名限制）,仅允许jpg,bmp,gif文件。
			su.setAllowedFilesList("jpg,bmp,gif");
			//上传文件
			su.upload();
			//将上传文件全部保存到指定目录
			su.save("/upload");
			//得到已上传的文件的输入流
			String filename=su.getFiles().getFile(0).getFileName();
			filename=pageContext.getServletContext().getRealPath("/upload/"+filename);
			FileInputStream bookImgFile=new FileInputStream(filename);
			//------将上传的图片放入到数据库表的对应字段中------
			Context initCtx = new InitialContext(); 
			Context ctx = (Context) initCtx.lookup("java:comp/env");
			Object obj = (Object) ctx.lookup("jdbc/sqlserver");
			DataSource ds = (javax.sql.DataSource)obj;
			Connection conn = ds.getConnection();
			Statement selectSQL=conn.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,ResultSet.CONCUR_UPDATABLE);
			ResultSet rs=selectSQL.executeQuery("select book_image from book where book_id="+su.getRequest().getParameter("book_id"));
			rs.next();
			rs.updateBinaryStream("book_image",bookImgFile,bookImgFile.available());
			rs.updateRow();
		} catch (Exception e) {
			e.printStackTrace();
		}
		return SKIP_BODY;
	}










}