【发布时间】：2013-04-04 12:16:05
【问题描述】：
我想从数据库中检索图像并将其显示到 jsp 页面。所以我创建了一个jsp页面，但我尝试了很多错误但无法修复它。 我可以在 servlet 中轻松做到这一点，但我需要在 jsp 中
<%@ page import="java.sql.*" %>
<%@ page import="java.io.*" %>
<%@page import ="DB.*" %>
<%// declare a connection by using Connection interface Connection connection = null;
/* Create string of connection url within specified format with machine
name, port number and database name. Here machine name id localhost
and database name is mahendra. */
Blob image = null;
Connection con = null;
Statement stmt = null;
ResultSet rs = null;
DataBaseConnection db= new DataBaseConnection();
ServletOutputStream out1 = 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) {
out1.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;
}
%>
错误是
HTTP Status 500 - java.lang.IllegalStateException: getOutputStream() has already been called for this response
type Exception report
message java.lang.IllegalStateException: getOutputStream() has already been called for this response
description The server encountered an internal error that prevented it from fulfilling this request.
exception
org.apache.jasper.JasperException: java.lang.IllegalStateException: getOutputStream() has already been called for this response
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:585)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:465)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
root cause
java.lang.IllegalStateException: getOutputStream() has already been called for this response
org.apache.catalina.connector.Response.getWriter(Response.java:639)
org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:214)
org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:125)
org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:118)
org.apache.jasper.runtime.PageContextImpl.release(PageContextImpl.java:190)
org.apache.jasper.runtime.JspFactoryImpl.internalReleasePageContext(JspFactoryImpl.java:126)
org.apache.jasper.runtime.JspFactoryImpl.releasePageContext(JspFactoryImpl.java:80)
org.apache.jsp.retrieveImage_jsp._jspService(retrieveImage_jsp.java:123)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.37 logs.
Apache Tomcat/7.0.37
【问题讨论】：
标签： java mysql image jsp servlets