我想显示存储在MySQL数据库中的图像。要检索图像，我使用的是servlet。请告诉我如何在jsp页面中显示它。这是流程：
login.html ---> dologin.jsp
login.html和servlet几乎准备好了。请告诉我如何完成dologin.jsp。
的login.html
<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>
的servlet
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
}
}
答案 0 :(得分：5)
为什么不尝试这样：
我有一个 getImageDetails.jsp 来根据user_id或名称或其他一些约束从数据库中检索图像数据，如下所示（将代码放在jsp / servlet页面中）
int img_id = Integer.parseInt(request.getParameter("your_id"));
Connection con = //get your connection object here ;
ResultSet rs = null;
PreparedStatement pstmt = null;
OutputStream oImage;
try {
pstmt = con.prepareStatement("your sql statement for retriving the image column data");
pstmt.setInt(1, img_id);
rs = pstmt.executeQuery();
if(rs.next()) {
byte barray[] = rs.getBytes(1);
response.setContentType("image/gif");
oImage=response.getOutputStream();
oImage.write(barray);
oImage.flush();
oImage.close();
}
}
catch(Exception ex){
//ex.printStackTrace();
}finally {
try{
if(con!=null)
con.close();
}catch(Exception ex){
// ex.printStackTrace();
}
}
然后我从html或任何其他jsp页面调用此页面如下
<强>＆LT; img src =“getImageDetails.jsp？your_id = 12”width =“50”height =“50”/＆gt;
请尝试这样你会得到答案
让我知道状态 快乐的编码