我找不到从 Db 获取 blob 图像并使用 jsp 在 img 标签中显示的解决方案。我尝试的代码如下，
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ page import="java.sql.*" %>
<%@ page import="java.io.*"%>
<!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=UTF-8">
<title>Insert title here</title>
</head>
<body>
<table border=1>
<%
try
{
Class.forName("com.mysql.jdbc.Driver");
Connection connection =DriverManager.getConnection("jdbc:mysql://localhost:3306/raptor1_5","root","");
Statement st=connection.createStatement();
ResultSet rst = st.executeQuery("select * from contacts");
while(rst.next())
{
Blob image = rst.getBlob("Images");
byte[ ] imgData = null ;
imgData = image.getBytes(1,(int)image.length());
String answer = rst.getString("Answers");
//response.setContentType("image/gif");
//OutputStream o = response.getOutputStream();
%>
<tr>
<td><img src="<%=imgData %>" alt="images Here" width="130px" height="90px"></td>
<td><%=answer %></td>
</tr>
<%}
}
catch(Exception e)
{
e.printStackTrace();
}
%>
</table>
</body>
</html>
我尝试了很多问题，例如从 <img> 中的数据库检索 blob 文件但我不明白如何显示。所以请有人告诉我如何在 <img> 中获取 Blob 图像使用jsp动态标记。
我希望有人能帮助我......!
最佳答案
您可以尝试使用带有数据 url 的内联图像，更多信息请参见:http://www.websiteoptimization.com/speed/tweak/inline-images/
这将数据编码为 base64。
String imgDataBase64=new String(Base64.getEncoder().encode(imgData));
这用于在网页中显示图像
<img src="data:image/gif;base64,<%= imgDataBase64 %>" alt="images Here" width="130px" height="90px"/>
如果你的base64有问题，你可以使用https://gist.github.com/EmilHernvall/953733中的这个函数
public static String encode(byte[] data)
{
char[] tbl = {
'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/' };
StringBuilder buffer = new StringBuilder();
int pad = 0;
for (int i = 0; i < data.length; i += 3) {
int b = ((data[i] & 0xFF) << 16) & 0xFFFFFF;
if (i + 1 < data.length) {
b |= (data[i+1] & 0xFF) << 8;
} else {
pad++;
}
if (i + 2 < data.length) {
b |= (data[i+2] & 0xFF);
} else {
pad++;
}
for (int j = 0; j < 4 - pad; j++) {
int c = (b & 0xFC0000) >> 18;
buffer.append(tbl[c]);
b <<= 6;
}
}
for (int j = 0; j < pad; j++) {
buffer.append("=");
}
return buffer.toString();
}
要使用它，只需
String imgDataBase64=encode(imgData));
关于java - 如何在jsp中获取img标签中的blob图像，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/28064920/