Servlet_从数据库中查询图片的servlet-优快云博客

本文介绍了一个用于从数据库中检索商品图片并将其返回给客户端的Servlet实现。该Servlet通过接收产品ID参数，查询数据库获取对应的图片Blob数据，并将其作为JPEG图像流发送给请求者。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

<img src='servlet/ImgProduct?pid="+pid+"'/>

*********servlet/ImgProduct的写法*********
package commons;

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import db.GlobalVars;
//商品图片的产生
public class ImgProduct extends HttpServlet {
    @Override

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String key1=(String)request.getParameter("pid");
        response.setContentType("image/jpeg");
        ServletOutputStream out = response.getOutputStream();
        Connection con = GlobalVars.pool.getConn();
        System.out.println("con:" + con);
        PreparedStatement ps = null;
        ResultSet rs = null;
        String sql = "select pphoto from Products where pid=?";
        try {
            ps = con.prepareStatement(sql);
            ps.setInt(1, Integer.parseInt(key1));
            rs = ps.executeQuery();
           
            if (rs.next()) {
                InputStream input = rs.getBlob(1).getBinaryStream();
                byte[] b = new byte[1024];
                int x = 0;
                while ((x = input.read(b)) != -1) {
                    out.write(b, 0, x);
                    System.out.println("X:"+x);
                }
            }

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                rs.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }
            try {
                ps.close();
            } catch (SQLException e) {
                e.printStackTrace();
            }

            GlobalVars.pool.close(con);
        }
        out.flush();
        out.close();

   

    }

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request,response);
    }
   
   

}