URLConnection/getOutputStream in Applet init/start

I have attempted to make a URLConnection to a servlet at the same address as the servlet that launched an applet(I have confirmed the address via getDocumentBase, both are on my PC) in the applet's init and start methods.  The connection appears to work but when I do a getOutputStream (also in the applet's init and start methods) on the URLConnection I get a SecurityException (cannot access localhost).  An URLConnection/getOutputStream to the same servlet works in a method that executes after init and start have completed.
Who is Participating?
Ravindra76Connect With a Mentor Commented:
Applet has no constructors:- ( We won't use but we can use and not recommonded..)

>The browser invokes your constructor, then setStub, then init(). Hence when your constructor is
invoked, the AppletStub (and through it the AppletContext) is not yet available. Although in principle you
can do things in the constructor that don't  rely (even indirectly) on the AppletStub or AppletContext, it is
less error-prone to simply defer all setup to the init method. That way you know that anything that needs
the stub/context will have it available.
Visit this for more info



int servletport = 8080; //Replace Ur servlet port
URLConnection con = new URL("http://"+getCodeBase().getHost()+":"+servletport+

i.e just replace



SDeprezAuthor Commented:
getCodeBase returns the directory that the applet was loaded from (i.e. file://D:/Projects/projectname).  In this case, getCodeBase().getHost() isn't returning anything.  getDocumentBase returns the URL for the servlet that loaded this applet (i.e. http://localhost:8080/servlet/servletname).  The servlet I'm connecting to has the same URL for the exception of the servletname.
Cloud Class® Course: Microsoft Windows 7 Basic

This introductory course to Windows 7 environment will teach you about working with the Windows operating system. You will learn about basic functions including start menu; the desktop; managing files, folders, and libraries.

Note one point:-

      The only way the applet will connect to servlet unless it is signed is with

      server name as getCodeBasse().getHost().

Since U are not using webserver , U are getting d:\..\..\.

Don't run applet like that.

Load Your applet from webserver

Then only it will work.

Applet when executing in browser will feel localhost as also as remove server.
It won't know that that is the server from which it is downloaded.
SDeprezAuthor Commented:
Adjusted points from 50 to 75
SDeprezAuthor Commented:
Then why does this work ok when I put the URLConnection/getOutputStream in an applet method other than init or start?

Are U using Browser or AppletViewer??

IE or NEtscape ??
I told all the matter for browsers.
SDeprezAuthor Commented:
I'm using IE with servletrunner.  

I'm afraid I don't totally understand your answer.  Are you saying that since init and start are invoked by the browser (and the other methods are not) that the URLConnect/getOutputStream work differently?  

I do appreciate your assistance!!!
once an applet connected to servlet,

it won't connect again. It will give U exception.

getCodeBase() like functions are available after applet is inited.
SDeprezAuthor Commented:
I think you just answered my question.  Let me know if I understand you correctly.  In a nutshell, getCodeBase, URLConnection, etc. are not available until after an applet's start and init methods have completed?  
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.