Oreilly servlet String Value manupulation - string

I am trying to truncate a string using Oreilly servlet classes.
My problem is that I don't want to use the whole string but a part of it. paramPart.getStringValue()
will give the value uncut but I have a scenario which requires I get a part of the string.
for example: The String value could be "xxxyyyy ,,," while I only require to work with "xxxyyyy". I hope my problem is clear to that point.. Any help will be highly appreciated.
Pss
Am using com.oreilly.servlet classes on my jsp application.

I found a solution to my problem which worked just fine, using java's substring() method.
first I got the value by String value = paramPart.getStringValue();
then I went ahead and created another variable String valuetrucated = value.substring(0, value.length() - 2);
this will truncate the string value to the 3rd char from the end of the string...

Related

Concatenation with empty string raises ERR:INVALID DIM

In TI-BASIC, the + operation is overloaded for string concatenation (in this, if nothing else, TI-BASIC joins the rest of the world).
However, any attempt to concatenate involving an empty string raises a Dimension Mismatch error:
"Fizz"+"Buzz"
FizzBuzz
"Fizz"+""
Error
""+"Buzz"
Error
""+""
Error
Why does this occur, and is there an elegant workaround? I've been using a starting space and truncating the string when necessary (doesn't always work well) or using a loop to add characters one at a time (slow).
The best way depends on what you are doing.
If you have a string (in this case, Str1) that you need to concatenate with another (Str2), and you don't know if it is empty, then this is a good general-case solution:
Str2
If length(Str1
Str1+Str2
If you need to loop and add a stuff to the string each time, then this is your best solution:
Before the loop:
" →Str1
In the loop:
Str1+<stuff_that_isn't_an_empty_string>→Str1
After the loop:
sub(Str1,2,length(Str1)-1→Str1
There are other situations, too, and if you have a specific situation, then you should post a simplified version of the relevant code.
Hope this helps!
It is very unfortunate that TI-Basic doesn't support empty strings. If you are starting with an empty string and adding chars, you have to do something like this:
"?
For(I,1,3
Prompt Str1
Ans+Str1
End
sub(Ans,2,length(Ans)-1
Another useful trick is that if you have a string that you are eventually going to evaluate using expr(, you can do "("+Str1+")"→Str1 and then freely do search and replace on the string. This is a necessary workaround since you can't search and replace any text involving the first or last character in a string.

issues while serializing to YAML file

I have started using .net API for yaml and it seems to be helpful. However I have few questions and wondering if you can provide some sample/work around for the same.
(1) I have an object consisting 4 strings I would like to serialize its collection (List or String[]). I wrote a helper method to return me the strings in the format I want, however it adds an extra single quote before and after the string. So I am getting
-'{str1: str2, str3: str4}'
-'{str5: str6, str7: str8}'
instead of
-{str1: str2, str3: str4}
-{str5: str6, str7: str8}
Can you suggest any workarounds?
(2) I am trying to insert xaml as a string in a yaml document. My xaml is well formed xml but when I serialize it, it cuts before 3rd last element. Any idea why?
Regarding the first question, if you are serializing an array of strings, then it is normal that each element is quoted because it starts with a '{'. In this case, you should be serializing the list of objects directly instead of converting them to string first.
Regarding the second question, you should add some code to the question to clarify what you are doing.

Is it possible to store a binary string to memcached and then get it back in application?

In my project i want to store a binary string (string like "010101010101") to memcached and then retrieve it back when needed,
it seems that i can store the string successfully to memcached as "get xxx" gives me a result similar to original one,
but when i use "memcached_get" function to get the result in my code, the return string is not the same to the original binary string,
the length of the return string is much shorter than the original one.
Who can tell my why, is it possible to store binary string to memcached?
Thank you and looking forward your replies~!
Daniel.
Hi Joachim and rekire,
I have solved the problem yet.
I used libmemcache c++ client in my code, the return of "memcache_get" call is char*, i just used string value = string(xxx) to convert the char* to a string.
But actually the binary string contains '\r\n' thus i just got the string before the first '\r\n' and lost the rest data, that's the key point to the problem.
Now i just used string.append(xxx, length) to get the whole binary sequence.
rekire, thanks for your tips, the cause of the problem is similar to your suggestion.
Thank you~!

Quick variable question

I have an EditText object (et_travel) on my screen that's asking for miles traveled. I grab that data like this:
float travel = Float.parseFloat(et_travel.getText().toString());
if(travel > 40000){
I just discover that if someone puts 40000 in the EditText, everything works fine, but if they put 40,000 (adding a comma to the number), I force close on the float travel = ...statement.
How can I evaluate the number without having a problem from the user adding a comma?
Is this in Java? It appears to be, but I'm wondering if I'm mistaken. Regardless, I would suggest you remove all of the characters from the string that are not of a numeric type. A way to do this may be using a regular expression.
A way to do this in Java may be the following:
String input = et_travel.getText().toString();
input = input.replaceAll("[^0-9]", "");
float travel = Float.parseFloat(input);
...
This way, you strip anything that is a non-numeric value from the string first, and then attempt to do your work. Obviously do some error checking before this (like input is not null and such). One change that is needed however is that you may need to maintain the '.' character (if you're given non-integer values). This would require changing the first regex a bit.
Check here: http://download.oracle.com/javase/1.5.0/docs/api/java/lang/String.html#replaceAll(java.lang.String, java.lang.String)
What you need is some validation on the input. Before converting the string into a float parse the string. If there are any ','s then remove them. If there is just junk then reject the input, otherwise someone could put a word or anything else in the input and cause havoc in your program.
Check out
inputType to restrict user input
android:inputType="number"

How do I pass a String into a function in an NVelocity Template?

I'm using the NVelocity Templating engine to produce a fixed-length field output - you know the kind of thing:
Field Start Pos Field Length Notes
---------- --------- ------------ ---------
Supplier 1 7 Leading Zeros
GRN 8 9 -
...
e.g.
>0001234 123A<
The problem is I'm trying to call String.PadRight() with the overload to specify the leading zero, and NVelocity is having none of it..
This works:
$Document.SupplierCode.PadRight(7)
But this doesn't:
$Document.SupplierCode.PadRight(7,"0")
I've tried:
Single Quotes ('0')
Double Single-Quotes (''0'')
Double Quotes ("0")
Double Double-Quotes (""0"")
Escaping the quotes for all of the above (\"0\")
No Quotes!
All I've found to work from is the NVelocity Homepage, and the Velocity Templating Language Reference page, niether are pointing me at a solution.
Sorry I'm unable to supply or point you somewhere where you can test out your ideas for yourself, but any suggestions you may have will be most welcome!
Thanks for your help ;o)
I'm coping with the same problem at the moment, as far as I understand it is due to the fact that PadLeft and PadRight functions of String class receive the second parameter, the leading "0", as a char, not as a string.
NVelocity allows you to specify the parameter as a string using '0', but in this way internally it generate a cast exception (or something similar), because the parameter is expected as char.
I haven't found yet (I'm just using NVelocity since 1 hour!) a way to specify the parameter as char, at the moment I have just a dirty solution such as applying a Replace(" ", "0") after the PadLeft / PadRight, so the template becomes
$Document.SupplierCode.PadRight(7).Replace(' ', '0')
One solution that a colleague has come up with is to create another property in the Document object that returns the formatted String:
E.g.
Public ReadOnly Property SupplierCodeFormatted() As String
Get
Return Supplier.Code.PadLeft(7, "0")
End Get
End Property

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