Develop Reference

Using regex to find chars in a string and replace

When returning a string value from an incoming request in my network based app, I have a string like this
'post http://a.com\r\nHost: a.com\r\n'
Issue is that the host is always changing so I need to replace it with my defined host. To accomplish that I tried using regex but am stuck trying to find the 'host:a.com' chars in the string and replacing it with a defined valued.
I tried using this example www.javamex.com/tutorials/regular_expressions/search_replace_loop.shtml#.VUWvt541jqB changing the pattern compile to :([\\d]+) but it still remains unchanged.
My goal is to replace given chars in a string with a defined value and returning the new string with the defined value.
Any pointers?
EDIT:
Sample of a typical incoming request:
Post http://example.com\r\nHost: example.com\r\nConnection: close\r\n
Another incoming request might take this form:
GET http://example2.net\r\nContent-Length: 2\r\nConnection: close\r\nHost: example2.net\r\n
I want to replace it to this forms
Post http://example.com\r\nHost: mycustomhostvalue.com\r\nConnection: close\r\n
GET http://example2.net\r\nContent-Length: 2\r\nConnection: close\r\nHost: mycustomhostvalue.com\r\n

Use a regex to replace it, like this:
content = content.replaceAll("Host:\\s*(\\w)*\\.\\w*", "Host: newhost.com")
This will replace anything after Host: with newHost.com.
Note: as per comment by cfqueryparam, you may want to usea regex like this to cover .co.uk and such:
Host:\\s*.*?(?=\\\\r\\\\n)

get all values using get paremeters in java

I'm passing the some values url from flex to java example:
URL format:
../mahesh/initUser.do?method=fwdAccDetails&securityId=mUuB3/p/ky5JhZPY5T8Znf01YCcIarIalQiGEXPMMsOkWDX+KtT4fx2gMML+uup8
After I'm tiring to get "securityId" values in java like
request.getParameter("securityId")
But I'm getting following values only
mUuB3/p/ky5JhZPY5T8Znf01YCcIarIalQiGEXPMMsOkWDX KtT4fx2gMML uup8
symbol getting empty space in java side..
Here is my Flex code:
navigateToURL(new URLRequest('../mahesh/initUser.do?method=fwdAccDetails&securityId='+value+'),'_s‌​elf');
I didn't get full values.. any one can help me how I will get correct values in Java..

You should use the encodeURIComponent()-Function to properly encode your securityId.
value = encodeURIComponent(value);
navigateToURL(new URLRequest('../mahesh/initUser.do?method=fwdAccDetails&securityId='+value+'),'_s‌​elf');
That way your String will be correct on the Java side.
If you want to read more about proper escaping, have a look at When are you supposed to use escape instead of encodeURI / encodeURIComponent? (Same arguments apply for Flex and JavaScript).

i just resolve my issue for following code in a javURLDecoder.decode(param1AfterEncoding.replace("+", "%2B"), "UTF-8").replace("%2B", "+")
Now its working fine only.. i dint other special character will work fine.. i will check it later..

401 response when do a POST using scribe oauth java [duplicate]

I am trying to use Twitter OAuth and my POST requests are failing with a 401 (Invalid OAuth Request) error.
For example, if I want to post a new status update, I am sending a HTTP POST request to https://twitter.com/statuses/update.json with the following parameters -
status=Testing&oauth_version=1.0&oauth_token=xxx&
oauth_nonce=xxx&oauth_timestamp=xxx&oauth_signature=xxx&
oauth_consumer_key=xxx&in_reply_to=xxx&oauth_signature_method=HMAC-SHA1`
My GET requests are all working fine. I can see on the mailing lists that a lot of people have had identical problems but I could not find a solution anywhere.
I am using the oauth.py Python library.

I just finished implementing twitter OAuth API from scratch using Java. Get and post requests work OK. You can use this page http://www.hueniverse.com/hueniverse/2008/10/beginners-gui-1.html to check signature and HTTP headers. Just enter your keys and tokens and check output. It seems twitter works exactly as described on this post. Be careful with spaces and UTF-8 symbols, for example Java encodes space as "+" but OAuth requires %20

Make sure your app access type is read & write.
On your app settings page (ex. http://twitter.com/apps/edit/12345) there's a radio button field like this:
Default Access type: Read & Write / Read-only
If you check 'Read-only' then status update API will return 401.

I second the answer by Jrgns. I has exactly the same issue. When reading the example Twitter provides, it's actually clear. However their pseudo code is misleading. In Python this worked for me :
def encodekeyval(key, val):
key = urllib.quote(key, '')
val = urllib.quote(val, '')
return urllib.quote(key + '=' + val, '')
def signature_base_string(urlstr, oauthdata):
sigstr = 'POST&' + urllib.quote(urlstr,'') + '&'
# retrieve "post" data as dictionary of name value pairs
pdata = oauthdata.getpdata()
# need to sort parameters
pstr = '%26'.join([encodekeyval(key, pdata[key]) for key in sorted(pdata.keys())])
return sigstr + pstr

I had the same issues, until I realised that the parameters need to be encoded twice for the base string. My GET requests all worked fine, but my POSTs, particularly status updates, failed. On a hunch I tried a POST without spaces in the status parameter, and it worked.
In PHP:
function encode($input) {
return str_replace('+', ' ', str_replace('%7E', '~', rawurlencode($input)));
}
$query = array();
foreach($parameters as $name => $value) {
$query[] = encode($name) . '=' .encode($value);
}
$base = encode(strtoupper($method)) . '&' .encode($norm_url) . '&' .
encode(implode('&', $query));
Notice the encode function around the names and values of the parameters, and then around the whole query string. A Space should end up as %2520, not just %20.

I found the solution and it works for me, You must add the following paramters in the request header and it should look like following (c# code), donot use & sign, instead separate parameters by comma(,) sign. and you must add the word "OAuth" in the beginging.
httpWebRequest.Headers[System.Net.HttpRequestHeader.Authorization] = "OAuth oauth_consumer_key=\"hAnZFaPKxXnJqdfLhDikdw\", oauth_nonce=\"4729687\", oauth_signature_method=\"HMAC-SHA1\", oauth_timestamp=\"1284821989\", oauth_token=\"17596307-KH9iUzqTxaoa5576VjILkERgUxcqExRyXkfb8AsXy\", oauth_version=\"1.0\", oauth_signature=\"p8f5WTObefG1N9%2b8AlBji1pg18A%3d\"";
and other parameters like 'status' should be written in the body of the request.

Most likely, the signature is invalid. You must follow the OAuth spec on how to generate the signature( normalized parameters, URLencoding, and cosumerSecret&oauthScret. More on this later ......

Velocity - How to avoid ParseErrorException when using jQuery?

I'm trying to add a jQuery post to some JavaScript on a web page. The entire page is built up of several Velocity templates. Everything has been fine until I've tried to add the jQuery post, now I get:
org.apache.velocity.exception.ParseErrorException: Encountered "," at line 282, column 24 of /WEB-INF/velocity/www/comments.vm
Was expecting one of:
"(" ...
<RPAREN> ...
<ESCAPE_DIRECTIVE> ...
~~~snip~~~
Line 282 is $.post(... and column 24 appears to be the first "," character. Initially I had the JSON on this line, but I moved it up (to the var myJSONObject ... line)as I thought the error related to invalid JSON (tabs at the start of the line gave a misleading column number).
var myJSONObject = {"body": "", "action": "postcomment", "submitted": "true", "ajax": "true"};
myJSONObject.body = $("body").val();
$.post("$!{articleurl}", myJSONObject, function(result){
btn.textContent='Comment sent successfully.';
});
Minor Update
I changed the following lines:
var url = "$articleurl";
$.post(url, myJSONObject, function(result){
~~~snip~~~
The parse exception still focuses on the first ",". I'm assuming the issue is that Velocity thinks it should be able to resolve $.post - when in fact, it's jQuery. I've used jQuery in other Velocity VM templates without any problem. Is there a way to get Velocity to ignore certain lines / statements when parsing?
Update 2
I found this link about escaping references in Velocity, but it does not resolve my issue. Adding a "\" before $.post gives me the exact same error, but the column is one extra, because of the character added at the start of the line.

You can wrap your javascript with #[[ ... ]]# which tells Velocity to not parse the enclosed block (new in Velocity 1.7)
#[[
<script>
...
</script>
]]#

Ok, there appears to be two solutions for this:
First, with jQuery we can just avoid using the global alias $ and instead use the jQuery object directly:
jQuery.post(url, myJSONObject, function(result){
~~~snip~~~
In my case, the above works great. But I suspect in other scenarios (non-jQuery) this may not be possible. In which case, we can 'hide' our character within a valid Velocity reference like this:
#set( $D = '$' )
${D}
Source: http://velocity.apache.org/engine/devel/user-guide.html#escapinginvalidvtlreferences
I'd still like to know why the backslash escape didn't work, but the above will at least get me moving again. :)

I think this is a bug in version 1.6.x, because it works fine in 1.7(If it did not, please tell me, I test it many times..), according to the reference, the $ takes effect only when it is followed by a-zA-Z. I want to try do debug what happened really, but the translation code is generated by Java CC tool, it is too hard to recognize the logic...

you must create a js file with your javascript code
and import your js file into your vm code

I couldn't get it to work with any of the other fixes like escaping "$" in velocity unfortunately. I got it working by loading an external js-file with the jQuery instead of writing jQuery directly in velocity. Worked out for me at least, hope it helps someone :)
/björn

Java -> Apache Commons StringEscapeUtils -> escapeJavaScript

For a very simple ajax name lookup, I'm sending an id from the client webpage to the server (Tomcat 5.5, Java 5), looking it up in a database and returning a string, which is assigned to a javascript variable back in the client (and then displayed).
The javascript code that receives the value is pretty standard:
//client code - javascript
xmlHttp.onreadystatechange=function() {
if (xmlHttp.readyState==4) {
var result = xmlHttp.responseText;
alert(result);
...
}
...
}
To return the string, I originally had this in the server:
//server code - java
myString = "...";
out.write(myString.getBytes("UTF-8"));
Which worked perfectly, if unsafe. Later, I replaced it with:
import org.apache.commons.lang.StringEscapeUtils;
...
myString = "...";
out.write(StringEscapeUtils.escapeJavaScript(myString).getBytes("UTF-8"));
But while safer, the resulting string can't be properly displayed if it contains special chars like "ñ".
For instance, using:
escapeJavaScript("años").getBytes("UTF-8");
sends:
an\u00F1os
to the client.
The question: is there a simple way to parse the resulting string in Javascript or is there an alternate escape function I can use in java that would prevent this issue?

The following works in every browser I've tried:
javascript:alert("a\u00F1os");
Perhaps your string is being escaped twice by mistake.

Actually, now that I read it over, I think I actually don't need to escape the string I'm sending back at all... That is, StringEscapeUtils.escapeJavaScript would be useful if the resulting value was printed in the page, like:
//javascript code with inline struts
var myJavasriptString = "<%=myJavaString%>";
Or am I missing something and there would still be a valid reason to do the escape in the original case? (when it is returned as a series of bytes back to an ajax onreadystatechange handler and assigned to a js variable)