我在AttachedFiles.jsp页面中收到以下错误：
SEVERE: Servlet.service() for servlet [jsp] in context with path [/da8] threw exception [java.lang.IllegalStateException: getOutputStream() has already been called for this response] with root cause
java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.catalina.connector.Response.getWriter(Response.java:678)
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:213)
at org.apache.jasper.runtime.JspWriterImpl.initOut(JspWriterImpl.java:125)
at org.apache.jasper.runtime.JspWriterImpl.flushBuffer(JspWriterImpl.java:118)
at org.apache.jasper.runtime.PageContextImpl.release(PageContextImpl.java:194)
at org.apache.jasper.runtime.JspFactoryImpl.internalReleasePageContext(JspFactoryImpl.java:126)
at org.apache.jasper.runtime.JspFactoryImpl.releasePageContext(JspFactoryImpl.java:80)
at org.apache.jsp.jsp.AttachedFiles_jsp._jspService(AttachedFiles_jsp.java:786)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)
我以前的版本有：
fileIn.close();
outStream.flush();
outStream.close();
，但我认为在finally块中关闭所有对象是一个好习惯。 我还读到close（）也刷新了OutputStream。
在我做出这个改变后，我遇到了上述错误：/
AttachedFiles.jsp
FileInputStream fileIn = null;
ServletOutputStream outStream = null;
try
{
File fileToDownload = new File(file);
response.setContentType("APPLICATION/OCTET-STREAM");
String fileName = request.getParameter("fileName");
if(fileName == null) fileName = "";
String disHeader = "Attachment; Filename=\""+fileName+"\"";
response.setHeader("Content-Disposition", disHeader);
fileIn = new FileInputStream(fileToDownload);
outStream = response.getOutputStream();
byte[] outputByte = new byte[(int) fileToDownload.length()];
//copy binary contect to output stream
while(fileIn.read(outputByte) != -1)
{
outStream.write(outputByte);
}
}
catch (IOException e)
{
e.printStackTrace();
}
finally
{
try
{
outStream.close();
if (fileIn != null)
fileIn.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
有谁知道我收到此错误的原因？
如果是这样，我应该在写入outputStream后立即在while循环中刷新吗？
答案 0 :(得分：0)
JSP编译成Servlet。它已经在生成的Servlet中准备了它的隐式对象：
你可以用来写。但是出来是一个作家，所以它写的字符。您可能想要写二进制文件。
如果将代码重写为 Servlet ，那将会很酷。它会更清洁。
否则，要解决一个JSP内部问题，可以说这里的内容很糟糕......不会很酷。