java 如何从 mysql db 检索图像并将其显示在 HTML 中的 <td> 和 <img> 标签中？
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时间：2020-10-31 16:45:50 来源:igfitidea点击:
How to retrieve image from mysql db and show it inside <td> and <img> tag in HTML?
提问by Sujitha Chandrasekaran
How to retrieve image from mysql db and show it inside tag in HTML and that img tag should be placed inside ? Here s my code: It displays only the image . Its not showing any content other than image.
如何从 mysql db 检索图像并将其显示在 HTML 中的标签内，并且 img 标签应该放在里面？这是我的代码：它只显示图像。它不显示图像以外的任何内容。
Thanks in advance.
提前致谢。
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<%@ page import="java.io.*"%>
<%@ page import="java.sql.*"%>
<%@ page import="java.util.*"%>
<%@ page import="java.text.*"%>
<%@ page import="javax.servlet.*"%>
<%@ page import="javax.servlet.http.*"%>
<%@ page import="javax.servlet.http.HttpSession"%>
<%@ page language="java"%>
<%@ page session="true"%>
<%
try{
//PrintWriter out=response.getWriter();
out.println("Retrieve Image Example!");
String driverName = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/";
String dbName = "db";
String userName = "root";
String password = "root";
Connection con = null;
Class.forName(driverName);
con = DriverManager.getConnection(url+dbName,userName,password);
Statement st = con.createStatement();
%>
<table border='1'>
<tr>
<td>Name:</td><td>
</td>My Name</td>
</tr>
<tr>
<td>Image:</td>
<td width=10px;>
<%
PreparedStatement pre1 = con.prepareStatement("select * from image where id="+8);
ResultSet rs1=pre1.executeQuery();
while(rs1.next())
{byte[] bytearray1 = new byte[4096];
int size1=0;
InputStream sImage1;
sImage1 = rs1.getBinaryStream(2);
response.reset();
response.setContentType("image/jpeg");
response.addHeader("Content-Disposition","filename=logo.jpg");
while((size1=sImage1.read(bytearray1))!= -1 )
{
response.getOutputStream().write(bytearray1,0,size1);
}
response.flushBuffer();
sImage1.close();
rs1.close();
}
out.println("Retrieved Successfully!");
pre.close();
con.close();
}
catch (Exception e){
out.println(e.getMessage());
}
%>
</td></tr>
</table>
</body>
</html>
回答by Nick Holt
Images are loaded as separate requests to the request that loaded the html. As such you need to:
图像作为单独的请求加载到加载 html 的请求中。因此，您需要：
- establish a URL encoding scheme that you use when specifying the
srcof theimgelement. - map a servlet (or similar) to that URL. The servlet loads the image based on the parameters of the URL returning that image in its response.
- 建立你指定的时候使用URL编码方案
src中的img元素。 - 将 servlet（或类似的）映射到该 URL。servlet 根据在其响应中返回该图像的 URL 参数加载图像。
回答by Sujitha Chandrasekaran
I found out.
我发现。
r.jsp:-
r.jsp：-
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>
<table border=2>
<tr><th>DISPLAYING IMAGE</th></tr>
<tr><td>hi</td></tr>
<tr><td>
<img src="retrieve.jsp" width=130 height=130>
</td></tr>
</table>
</body>
</html>
retrieve.jsp:-
检索.jsp：-
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
</head>
<body>
<%@ page import="java.io.*"%>
<%@ page import="java.sql.*"%>
<%@ page import="java.util.*"%>
<%@ page import="java.text.*"%>
<%@ page import="javax.servlet.*"%>
<%@ page import="javax.servlet.http.*"%>
<%@ page import="javax.servlet.http.HttpSession"%>
<%@ page language="java"%>
<%@ page session="true"%>
<%
try{
//PrintWriter out=response.getWriter();
out.println("Retrieve Image Example!");
String driverName = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/";
String dbName = "db";
String userName = "root";
String password = "root";
Connection con = null;
Class.forName(driverName);
con = DriverManager.getConnection(url+dbName,userName,password);
Statement st = con.createStatement();
PreparedStatement pre1 = con.prepareStatement("select * from image where id="+8);
ResultSet rs1=pre1.executeQuery();
while(rs1.next())
{byte[] bytearray1 = new byte[4096];
int size1=0;
InputStream sImage1;
sImage1 = rs1.getBinaryStream(2);
response.reset();
response.setContentType("image/jpeg");
response.addHeader("Content-Disposition","filename=logo.jpg");
while((size1=sImage1.read(bytearray1))!= -1 )
{
response.getOutputStream().write(bytearray1,0,size1);
}
response.flushBuffer();
sImage1.close();
rs1.close();
}
pre.close();
con.close();
}
catch (Exception e){
out.println(e.getMessage());
}
%>
</body>
</html>
