Why do I need to set content-type to html in this Java Servlet?_问答_开发者

Why do I need to set content-type to html in this Java Servlet?

开发者 https://www.devze.com 2023-01-23 14:34 出处：网络

import javax.servlet.http.*; import javax.servlet.*; import java.io.*; import java.util.Date; public class HelloServlet extends HttpServlet

相关专题：servlets xhtml

import javax.servlet.http.*;
import javax.servlet.*;
import java.io.*;
import java.util.Date;

public class HelloServlet extends HttpServlet
{
    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException,IOException
    {
        response.setContentType("text/html;charset=utf-8");
        PrintWriter out = response.getWriter();
        out.println("<html><head><title>only for test</title></head><body>Hello, world!html version</body></html>");
        out.flush();
        out.close();
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException,IOException
    {
        doGet(request, 开发者_如何学Pythonresponse);
    }
}

If I set the content-type to xhtml, then the web-browser would automatically open the save-file dialog. Why would this happen?

First of all, note that the right content-type for xhtml is not xhtml or text/xhtml, but application/xhtml+xml.

Anyway, you'll need to check whether the user agent can actually accept this content-type by examining the Accept HTTP request header. According to the W3C recommendation:

If the Accept header explicitly contains application/xhtml+xml (with either no "q" parameter or a positive "q" value) deliver the document using that media type.
If the Accept header explicitly contains text/html (with either no "q" parameter or a positive "q" value) deliver the document using that media type.
If the accept header contains "/" (a convention some user agents use to indicate that they will accept anything), deliver the document using text/html.

text/xhtml is not a valid content type so your browser won't know how to render it properly.

For XHTML 1.0 the content type is supposed to be text/html http://www.w3.org/TR/xhtml-media-types/#compatGuidelines (See point A.9)

Edit:

This is a better link that specifically discusses XHTML and its various allowed Content-Type's

http://www.w3.org/International/articles/serving-xhtml/

Either:

When you say set the content-type to xhtml you mean literally xhtml or text/xhtml — in which case the problem is that the content type for XHTML is application/xhtml+xml
You are using Internet Explorer 8 or lower, which doesn't support XHTML. Support is being added in IE9 and is only available if you are using the beta.

Its method that take string parameter and returns nothing.