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jsp页面画线总是报错啊!

摘要: jsp页面画线总是报错啊!

大家好,我想在jsp页面里面画条线,但是总是报错啊!下面是我的jsp页面代码:
<%@ page language="java" import="java.util.*" pageEncoding="GB2312"%>
<%@ page contentType="image/jpeg"%>
<%@ page import="java.awt.Graphics" %>
<%@ page import="java.awt.image.BufferedImage" %>
<%@ page import="javax.imageio.ImageIO" %>


<%
BufferedImage buffer=new BufferedImage(60,20,BufferedImage.TYPE_INT_RGB);

Graphics graphics=buffer.getGraphics();
graphics.drawLine(0,0,60,20);
ImageIO.write(buffer,"JPEG",response.getOutputStream());
%>

下面是tomcat服务器报的错误啊:

2006-4-22 19:02:48 org.apache.catalina.core.StandardWrapperValve invoke
严重: Servlet.service() for servlet jsp threw exception
java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.catalina.connector.Response.getWriter(Response.java:606)
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:195)
at org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:124)
at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:117)
at org.apache.jasper.runtime.PageContextImpl.release(PageContextImpl.java:191)
at org.apache.jasper.runtime.JspFactoryImpl.internalReleasePageContext(JspFactoryImpl.java:115)
at org.apache.jasper.runtime.JspFactoryImpl.releasePageContext(JspFactoryImpl.java:75)
at org.apache.jsp.image_jsp._jspService(org.apache.jsp.image_jsp:68)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:97)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:322)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148)
at org.apache.coyote.http11.Http11AprProcessor.process(Http11AprProcessor.java:831)
at org.apache.coyote.http11.Http11AprProtocol$Http11ConnectionHandler.process(Http11AprProtocol.java:652)
at org.apache.tomcat.util.net.AprEndpoint$Worker.run(AprEndpoint.java:1203)
at java.lang.Thread.run(Thread.java:595)

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这错误很容易,你的jsp不能有任何空格或回车符

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response.getOutputStream();
jsp中的response没有次方法
你要继承<%@page extends="javax.servlet.Servlet"%>

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楼上的大哥,我按照你们二个人说的做了,还是有问题,没有解决啊,能不能搞个简单的例子啊?

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