java - 如何在jsp页面上显示来自mysql数据库的图像？-6ren

java - 如何在jsp页面上显示来自mysql数据库的图像？

转载作者：可可西里更新时间：2023-11-01 07:59:15

<分区>

我想显示存储在 MySQL 数据库中的图像。为了检索图像，我使用了一个 servlet。请告诉我如何在jsp 页面中显示它。这是流程:

login.html ---> dologin.jsp

<html>
<head>
<style type="text/css">
html, body, div, h1, h2, h3, h4, h5, h6, p, img, dl,
  dt, dd, ol, ul, li, table, tr, td, form, object, embed,
  article, aside, command, details, fieldset,
  figcaption, figure, footer, group, header, hgroup, legend
{
  margin: 0;
  padding: 0;
  border: 0;
}
html {
  font: 82.5% verdana, helvetica, sans-serif;
  background: #fff;
  color: #333;
  line-height: 1;
  direction: ltr;
}
html, body {
  position: absolute;
  height: 100%;
  min-width: 100%;
}   

table {
  border-collapse: collapse;
  border-spacing: 0;
}


.signin-header {
  padding: 10px 12px 5px;
  background:#00AAFF;
  border: 1px solid #e5e5e5;
  width: 362px;
  float: right;
}
.signin-box {
  padding: 20px 25px 15px;
  background:#DEDEDE;
  border: 1px solid #e5e5e5;
  width: 335px;
  float: right;
}

.button {
  min-width: 46px;
  text-align: center;
  color: #444;
  font-size: 11px;
  font-weight: bold;
  height: 27px;
  padding: 0 8px;
  line-height: 27px;
  border-radius: 2px;
  transition: all 0.218s;
  border: 1px solid #dcdcdc;
  background-color: #f5f5f5;
  cursor: default;
}

*+html .button {
  min-width: 70px;
}

button.button,
input[type=submit].button {
  height: f1f1f1px;
  line-height: 29px;
  vertical-align: bottom;
  margin: 0;
}

.button:hover {
  border: 1px solid #c6c6c6;
  color: #333;
  text-decoration: none;
  transition: all 0.0s;
  background-color: #f8f8f8;
  box-shadow: 0 1px 1px rgba(0,0,0,0.1);
}
.button:active {
  background-color: #f6f6f6;
  box-shadow: inset 0 1px 2px rgba(0,0,0,0.1);
}
.button:visited {
  color: #666;
}  
.button-submit {
  border: 1px solid #3079ed;
  color: #fff;
  text-shadow: 0 1px rgba(0,0,0,0.1);
  background-color: #4d90fe;
}
.button-submit:hover {
  border: 1px solid #2f5bb7;
  color: #fff;
  text-shadow: 0 1px rgba(0,0,0,0.3);
  background-color: #357ae8;
}
button-submit:active {
  background-color: #357ae8;
  box-shadow: inset 0 1px 2px rgba(0,0,0,0.3);
}

.footer-bar {
  position: absolute;
  bottom: 0;
  height: 35px;
  width: 100%;
  border-top: 1px solid #ebebeb;
  overflow: hidden;
}
.footer {
  padding-top: 9px;
  font-size: .85em;
  white-space: nowrap;
  line-height: 0;
}
.footer ul {
  color: #999;
  float: left;
  max-width: 80%;
}
.footer ul li {
  display: inline;
  padding: 0 1.5em 0 0;
}
.footer a {
  color: #333;
}
.footer .lang-chooser-wrap {
  float: right;
  max-width: 20%;
}
.footer .lang-chooser-wrap img {
  vertical-align: middle;
}
.footer .attribution {
  float: right;
}
.footer .attribution span {
  vertical-align: text-top;
}
.content {
  padding: 0 44px;
}

.table {
  padding: 0 55px
}
</style>
<script type="text/javascript">
function ccheck()
{
uid=document.f1.uid.value;
cpass=document.f1.cpass.value;

if(uid=="" || uid==null)
{
alert("Plz. Enter Your User ID");
document.f1.uid.focus();
return false;
}
if(cpass=="" || cpass==null)
{
alert("Plz. Enter Your Password");
document.f1.cpass.focus();
return false;
}
return true;
}
</script>
<title>Login Page</title>
</head>
<body onload="document.f1.uid.focus()" style="background-image:url('medical.jpg');background-position: center">
    <form id="f1" name="f1" action="doDelete.jsp" method="get" onsubmit="return ccheck()">

        <img src="header.png"><br><br><br><br><br>
        <table><tr><td>
            <table class="table"><tr><td>
                <table class="table"><tr><td>
                    <div class="content"><div class="signin-header"><h3>Welcome to DiaEmr</h3></div></div>
                </td></tr>
                <tr><td>
                    <div class="content">
                    <div class="signin-box">
                    <p class="one">
                        Welcome to all at the <b>"Workshop on Ileal Interposition".</b><br>

                        <b>Brazil</b> to inaugurate & launch this very important Data Registry<br>
                        Key features of the solution-<br>
                    </div>  
                </div>
            </td></tr></table>
        </td>
        <td>image</td>
        <td>
            <table class="table"><tr><td>
                <div class="content">
                    <div class="signin-header">
                        <h3>Portal Login</h3>
                    </div>
                </div>
            </td></tr>
            <tr><td>
                <div class="content">
                    <div align="center" class="signin-box">
                        <table class="table"><tr><td>
                            <b>User ID</b></td>
                        <td><input name="uid" type="text" /></td>
                        </tr>
                        <tr><td>
                            <b>Password</b></td>
                        <td><input name="cpass" type="password" /></td>
                        </tr>
                        <tr>
                            <td><input type="submit" class="button button-submit" value="Submit" /></td>
                            <td><input type="reset" class="button button-submit" value="Reset" /></td>
                        <tr>New User<a href ="UserRegistration.jsp">Register</a></tr><br>
                        </tr></table>
                    </div>
                </div>
            </td></tr></table>
        </td></tr></table>
    </td></tr></table>
    <div class="footer-bar">
        <img align="left" src="footer.png">
    </div>
</form>
</body>
</html>

小服务程序

import java.sql.*;
import DB.DataBaseConnection;

import java.io.IOException;
import java.io.InputStream;

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

/**
 * Servlet implementation class imagetestServlet
 */
@WebServlet("/imagetestServlet")
public class imagetestServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public imagetestServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response) 
              throws IOException,ServletException {

                 Blob image = null;
                  Connection con = null;
                  Statement stmt = null;
                  ResultSet rs = null;
                  DataBaseConnection db= new DataBaseConnection();
                  ServletOutputStream out = response.getOutputStream();
                  try {
                  Class.forName("com.mysql.jdbc.Driver");
                  con=db.connet();
                  stmt = con.createStatement();
                  rs = stmt.executeQuery("select img from one where  id = '4'");
                  if (rs.next()) {
                  image = rs.getBlob(1);
                  } else {
                  response.setContentType("text/html");

                  out.println("<font color='red'>image not found for given id</font>");

                  return;
                  }
                  response.setContentType("image/gif");
             InputStream in = image.getBinaryStream();
              int length = (int) image.length();
              int bufferSize = 1024;
              byte[] buffer = new byte[bufferSize];
              while ((length = in.read(buffer)) != -1) {
              out.write(buffer, 0, length);
              }
              in.close();
              out.flush();

            } catch (Exception e) {
              response.setContentType("text/html");
              out.println("<html><head><title>Unable To Display image</title></head>");
              out.println("<body><h4><font color='red'>Image Display Error=" + e.getMessage() +
               "</font></h4></body></html>");
              return;
              } 
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
    }

}