Question

我用doPost方法创建了一个简单的jython servlet文件。我试图发布一个表单但是在servlet中我没有得到帖子值。以下是我尝试使用的代码。

Test.html
---------
<form action='Index.py' method='post'>
   <input type="text" name="username" value="ifti" />
   <input type="text" name="password" value="ifti1233" />
   <input type="submit" name="Submit" value="Submit" />
</form>

Index.py
--------

from javax.servlet.http import HttpServlet
import cgi, cgitb, os, sys, shutil
import urllib2
import org.python.util.PyFilter

cgitb.enable();

class Index(HttpServlet):
    def doPost(self,req,res):   
        res.setContentType("text/html")
        form = cgi.FieldStorage()
        out = res.getWriter()
        keys = form.keys()
        keys.sort()
        pageContent = "<br />number of keys: "+str(len(keys))
        for key in keys:
               pageContent += fieldStorage[ key ].value
        out.println(pageContent)

Answer 1

cgi.FieldStorage期望来自流程的标准输入或其环境的输入。这就是Web服务器和CGI请求处理程序协作以提供HTTP请求的方式。

然而，

Servlet使用不同的协议将原始HTTP请求从Web服务器传输到请求处理程序，并且不能从标准输入/环境中读取HTTP请求。这就是为什么cgi.FieldStorage()没有检测到任何帖子字段的原因。相反，已处理的请求在传递给HttpServletRequest的{{1}}对象中提供。您可以调用doPost()上的方法来获取帖子字段和标题，例如

HttpServletRequest

使用您的测试表单，您应该看到与此类似的输出：

import cgi
from pprint import pformat
from javax.servlet.http import HttpServlet

class Index(HttpServlet):
    def doPost(self,req,res):
        res.setContentType("text/html")
        out = res.getWriter()

        out.println('<strong>Headers</strong>')

        headers = {}
        for n in req.headerNames:
                headers[n] = req.getHeader(n)
        out.println('<pre>')
        out.println(pformat(headers))
        out.println('</pre><br />')

        out.println('<strong>Form fields</strong>')

        # get the POST data fields
        form = {}
        for field in req.parameterMap:
                form[field] = list(req.parameterMap[field])

#        # Alternative - if you *really* want a FieldStorage object, construct
#        # one from the request body, headers and faked environment variables.
#        # N.B. assumes that the request body is one line of POST data only.
#        from StringIO import StringIO
#        request_body = req.reader.readLine()
#        form = cgi.FieldStorage(fp=StringIO(request_body),
#                    headers=headers,
#                    environ={'REQUEST_METHOD': 'POST',
#                             'CONTENT_LENGTH': len(request_body)})

        out.println('<pre>%s</pre><br />' % pformat(form))

为什么在Jython Servlet post请求中fieldStorage为空

1 个答案: