您好我不知道为什么当我尝试从servlet加载图片时会发生这种情况。
这是我的JSP:
<%@ page contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<!DOCTYPE html>
<html>
<head>
</head>
<body bgcolor="${pickedBgCol}">
<h3><a href="/webapp2">Home</a></h3>
<h3>OS usage</h3>
<p>Here are the results of OS usage in survey that we completed.</p>
<img src="reportImage" />
</body>
</html>
这是我的servlet:
package hr.fer.zemris.java.servlets;
import java.awt.image.RenderedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
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;
import org.jfree.chart.ChartFactory;
import org.jfree.chart.JFreeChart;
import org.jfree.chart.plot.PiePlot3D;
import org.jfree.data.general.DefaultPieDataset;
import org.jfree.data.general.PieDataset;
import org.jfree.util.Rotation;
@WebServlet(name = "usagePieChart", urlPatterns = { "/reportImage" })
public class PieChartServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
resp.setContentType("image/png");
ServletOutputStream os = resp.getOutputStream();
PieDataset dataset = createDataset();
JFreeChart chart = createChart(dataset, "OS Usage");
RenderedImage chartImage = chart.createBufferedImage(400, 300);
ImageIO.write(chartImage, "png", os);
os.flush();
os.close();
}
你有什么想法,为什么它不会显示图片?
答案 0 :(得分:2)
src
代码的img
属性需要指向有效的网址
e.g。
<img src="/mywebbApp/reportImage" />