我正在尝试从数据库中检索多个图像并在另一个 JSP 页面中显示这些图像。 首先，我尝试在特定的 JSP 页面中显示单个图像，我检索到但显示显示为文件类型， 我想在特定的 JSP 页面中显示该图像。 我正在使用 MySQL 数据库。
我的 servlet 代码:
import java.io.IOException;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet("/Retrieve")
public class Retrieve extends HttpServlet {
static {
try {
Class.forName("com.mysql.jdbc.Driver");
} catch (ClassNotFoundException e) {
e.printStackTrace();
}
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException
{ Connection con = null;
PreparedStatement ps = null;
ResultSet rs = null;
try {
con = DriverManager.getConnection("jdbc:mysql://localhost:3306/vikas", "root", "root");
ps = con.prepareStatement("select * from rough");
rs=ps.executeQuery();
if (rs.next()) {
byte[] content = rs.getBytes("image");
response.setContentLength(content.length);
response.getOutputStream().write(content);
request.setAttribute("image", content);
RequestDispatcher rd=request.getRequestDispatcher("View.jsp");
rd.forward(request, response);
} else {
response.sendError(HttpServletResponse.SC_NOT_FOUND); // 404.
}
} catch (SQLException e) {
throw new ServletException("Something failed at SQL/DB level.", e);
}
}
}
jsp代码:
<%@ 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>Display Image</title>
</head>
<body>
<div>THE DISPLAY</div>
<div style="width:25%; height:25%">
<%request.getAttribute("image"); %>
</div>
</body>
</html>
最佳答案
尝试使用Base64编码，
使用Apache Commons Codec进行 Base64 编码。
byte[] content = rs.getBytes("image");
String base64Encoded = new String(Base64.encodeBase64(content), "UTF-8");
request.setAttribute("imageBt", base64Encoded);
从 JSP 中检索它
<img src="data:image/png;base64,${requestScope['imageBt']}"/>
对于多个图像，你可以尝试这样的方法，(我没有尝试过)
List<String> images = new ArrayList<>();
if (rs.next()) {
byte[] content = rs.getBytes("image");
images.add(new String(Base64.encodeBase64(content), "UTF-8"));
}
request.setAttribute("imageBt", images);
在 JSP 中
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<c:forEach var="img" items="${imageBt}">
<img src="data:image/png;base64, ${img}"/>
</c:forEach>
关于java - 从数据库检索图像并显示在另一个jsp页面中，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/52161192/