Unexpected output from URLEncoder in Java - java

I am trying to encode a URL parameter.
For example when I am encoding
qOddENxeLxL+13drGKYUgA==\n
using URL Encoder tool
It gives the following output which works when I request API
qOddENxeLxL%2B13drGKYUgA%3D%3D%5Cn
But when I am encoding URL from my Java code (Android) using URLEncoder.encode("qOddENxeLxL+13drGKYUgA==\n", "UTF-8");
It gives me the following result
qOddENxeLxL%252B13drGKYUgA%253D%253D%250A
I tried using other Encoding schemes too but could not produce the same result.

The issue is because the \n is being interpreted as a new line character. Java will treat \ inside a string as starting an escape sequence.
You have to escape it in order to get the same thing as in the URL you provided.
System.out.println(URLEncoder.encode("qOddENxeLxL+13drGKYUgA==\\n", "UTF-8"));
This will provide the same result:
qOddENxeLxL%2B13drGKYUgA%3D%3D%5Cn

The issue is that you are feeding \n to the URLEncoder tool, which doesn't understand it as an escape sequence and so gives you %5Cn, and to the Java compiler inside a string literal, which does understand it and so gives you 0x0A.

Figured out the issue, here string was getting encoded two times.
While passing parameter to Retrofit call it is getting encoded automatically by retrofit and I was passing encoded parameter to retrofit so it got encoded again.
BTW thanks for the explanations. :)

Related

Illegal base64 character "a" using java.util.Base64 from within Scala

Suppose I have the following Base64 encoded String from a github API call to a file: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As far as I see, this encoding is correct and only contains the standard alphabet of characters for a Base64 encoding. If I decode this encoding here, I get a correct translation. However, I tried various approaches to decode it programmatically and did not find a solution yet.
Let contentEncoded be the string containing the encoded file. I tried the following:
java.util.Base64.getDecoder.decode(contentEncoded)
java.util.Base64.getDecoder.decode(contentEncoded.getBytes)
java.util.Base64.getDecoder.decode(contentEncoded.getBytes(StandardCharsets.UTF_8))
java.util.Base64.getUrlDecoder.decode(contentEncoded))
java.util.Base64.getUrlDecoder.decode(contentEncoded.getBytes(StandardCharsets.UTF_8))
java.util.Base64.getMimeDecoder.decode(contentEncoded.replaceAll("\\n", "").replaceAll("\\r", ""))
However, all of them resulted in an error message: java.lang.IllegalArgumentException: Illegal base64 character a.
My question is: Am I not seeing something obvious? Are there some hidden control characters? Has anybody had similar issues and was able to fix them?
Just remove line breaks and it should work.
contentEncoded.replace("\n", "")
The following snippet decodes the encoding correctly:
val decodedWithMime = java.util.Base64.getMimeDecoder.decode(contentEncoded)
val convertedByteArray = decodedWithMime.map(_.toChar).mkString
as pointed out by comments, the error message Illegal Base64 character a corresponds to the hex value for the newline character \n. Using the Mime Decoder it is possible to decode the string without removing the newline characters beforehand.

Documenting JSON in URL not possible

In my Rest API it should be possible to retrieve data which is inside a bounding box. Because the bounding box has four coordinates I want to design the GET requests in such way, that they accept the bounding box as JSON. Therefore I need to be able to send and document JSON strings as URL parameter.
The test itself works, but I can not document these requests with Spring RestDocs (1.0.0.RC1). I reproduced the problem with a simpler method. See below:
#Test public void ping_username() throws Exception
{
String query = "name={\"user\":\"Müller\"}";
String encodedQuery = URLEncoder.encode(query, "UTF-8");
mockMvc.perform(get(URI.create("/ping?" + encodedQuery)))
.andExpect(status().isOk())
.andDo(document("ping_username"));
}
When I remove .andDo(document("ping_username")) the test passes.
Stacktrace:
java.lang.IllegalArgumentException: Illegal character in query at index 32: http://localhost:8080/ping?name={"user":"Müller"}
at java.net.URI.create(URI.java:852)
at org.springframework.restdocs.mockmvc.MockMvcOperationRequestFactory.createOperationRequest(MockMvcOperationRequestFactory.java:79)
at org.springframework.restdocs.mockmvc.RestDocumentationResultHandler.handle(RestDocumentationResultHandler.java:93)
at org.springframework.test.web.servlet.MockMvc$1.andDo(MockMvc.java:158)
at application.rest.RestApiTest.ping_username(RestApiTest.java:65)
After I received the suggestion to encode the URL I tried it, but the problem remains.
The String which is used to create the URI in my test is now /ping?name%3D%7B%22user%22%3A%22M%C3%BCller%22%7D.
I checked the class MockMvcOperationRequestFactory which appears in the stacktrace, and in line 79 the following code is executed:
URI.create(getRequestUri(mockRequest)
+ (StringUtils.hasText(queryString) ? "?" + queryString : ""))
The problem here is that a not encoded String is used (in my case http://localhost:8080/ping?name={"user":"Müller"}) and the creation of the URI fails.
Remark:
Andy Wilkinson's answer is the solution for the problem. Although I think that David Sinfield is right and JSONs should be avoided in the URL to keep it simple. For my bounding box I will use a comma separated string, as it is used in WMS 1.1: BBOX=x1,y1,x2,y2
You haven't mentioned the version of Spring REST Docs that you're using, but I would guess that the problem is with URIUtil. I can't tell for certain as I can't see where URIUtil is from.
Anyway, using the JDK's URLEncoder works for me with Spring REST Docs 1.0.0.RC1:
String query = "name={\"user\":\"Müller\"}";
String encodedQuery = URLEncoder.encode(query, "UTF-8");
mockMvc.perform(get(URI.create("/baz?" + encodedQuery)))
.andExpect(status().isOk())
.andDo(document("ping_username"));
You can then use URLDecoder.decode on the server side to get the original JSON:
URLDecoder.decode(request.getQueryString(), "UTF-8")
The problem is that URIs have to be encoded as ACII. And ü is not a valid ASCII character, so it must be escaped in the url with % escaping.
If you are using Tomcat, you can use URIEncoding="UTF-8" in the Connector element of the server.xml, to configure UTF-8 escaping as default. If you do this, ü will be automatically converted to %C3%BC, which is the ASCII representation of the \uC3BC Unicode code-point (which represents ü).
Edit: It seems that I have missed the exact point of the error, but it is still the same error. Curly braces are invalid in a URI. Only the following characters are acceptable according to RFC 3986:
ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-._~:/?#[]#!$&'()*+,;=%
So these must be escaped too.

URLDecoder giving unexpected value on UTF-8 url parameter

I'm using java.net.URLDecoder to decode a URL parameter that is supposed to be encoded in UTF-8. A quick test reveals I'm getting ? instead of ∩ in the output. Here's the code:
System.out.println(java.net.URLDecoder.decode("A%E2%88%A9B%0AYour+answer+is%3A+3", "UTF-8"));
And as output I'm getting:
A?B
Your answer is: 3
When I plug the string A%E2%88%A9B%0AYour+answer+is%3A+3 into web decoders (e.g. here or here), they get it right:
A∩B
Your answer is: 3
Does anyone know what I'm doing wrong. Is this not actually UTF-8? The string is coming from com.google.gwt.http.client.URL.encodeQueryString(), which claims UTF-8 encoding.
As Siguza and VGe0rge pointed out, the Java code was running correctly, but Eclipse's console will not display in UTF-8 by default. A solution to that issue can be found here.

getParameter special characters

I'm trying to get an url parameter in jee.
So I have this kind of url :
http://MySite/MySite.jsp?page=recherche&msg=toto
First i tried with : request.getParameter("msg").toString();
it works well but if I try to search "c++" , the method "getParameter()" returns "c" and not "c++" and i understand.
So I tried another thing. I get the current URL and parse it to get the value of the message :
String msg[]= request.getQueryString().split("msg=");
message=msg[1].toString();
It works now for the research "c++" but now I can't search accent. What can I do ?
EDIT 1
I encode the message in the url
String urlString=Utils.encodeUrl(request.getParameter("msg"));
so for the URL : http://MySite/MySite.jsp?page=recherche&msg=c++
i have this encoded URL : http://MySite/MySite.jsp?page=recherche&msg=c%2B%2B
And when i need it, i decode the message of the URL
String decodedUrl = URLDecoder.decode(url, "ISO-8859-1");
Thanks everybody
Anything you send via "get" method goes as part of the url, which needs to be urlencoded to be valid in case it contains at least one of the reserved characters. So, any character will need to be encoded before sending.
In order to send c++, you would have to send c%2B%2B. That would be interpreted properly at the server side.
Here some reference you can check:
http://www.blooberry.com/indexdot/html/topics/urlencoding.htm
Now the question is, how and where do you generate your URL? According to the language, you will need to use the proper method to encode your strings.
if I try to search "c++" , the method "getParameter()" returns "c" and not "c++"
Query parameters are treated as application/x-www-form-urlencoded, so a + character in the URL means a space character in the parameter value. If you want to send a + character then it needs to be encoded in the URL as %2B:
http://MySite/MySite.jsp?page=recherche&msg=c%2B%2B
The same applies to accented characters, they need to be escaped as the bytes of their UTF-8 representation, so été would need to be:
msg=%C3%A9t%C3%A9
(é being Unicode character U+00E9, which is C3 A9 in UTF-8).
In short, it's not the fault of this code, it's the fault of whatever component is responsible for constructing the URL on the client side.
Call your URL with
msg=c%2B%2B
+ in a URL mean 'space'. It needs to be escaped.
You need to escape special characters when passing them as URL parameters. Since + means space and & means and another parameter, these cannot be used as parameter values.
See this other S.O. question.
You may want to use the Apache HTTP client library to help you with the URL encoding/decoding. The URIUtil class has what you need.
Something like this should work:
String rawParam = request.getParameter("msg");
String msgParam = URIUtil.decode(rawParam);
Your example indicates that the data is not being properly encoded on the client side. See this JavaScript question.

Escaping & in a URL

I am using jsps and in my url I have a value for a variable like say "L & T". Now when I try to retrieve the value for it by using request.getParameter I get only "L". It recognizes "&" as a separator and thus it is not getting considered as a whole string.
How do I solve this problem?
java.net.URLEncoder.encode("L & T", "utf8")
this outputs the URL-encoded, which is fine as a GET parameter:
L+%26+T
A literal ampersand in a URL should be encoded as: %26
// Your URL
http://www.example.com?a=l&t
// Encoded
http://www.example.com?a=l%26t
You need to "URL encode" the parameters to avoid this problem. The format of the URL query string is:
...?<name>=<value>&<name>=<value>&<etc>
All <name>s and <value>s need to be URL encoded, which basically means transforming all the characters that could be interpreted wrongly (like the &) into %-escaped values. See this page for more information:
http://www.w3schools.com/TAGS/ref_urlencode.asp
If you're generating the problem URL with Java, you use this method:
String str = URLEncoder.encode(input, "UTF-8");
Generating the URL elsewhere (some templates or JS or raw markup), you need to fix the problem at the source.
You can use UriUtils#encode(String source, String encoding) from Spring Web. This utility class also provides means for encoding only some parts of the URL, like UriUtils#encodePath.

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