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How to upload files to server using JSP/Servlet?
...TML <input type="file"> field in the form. As stated in the HTML specification you have to use the POST method and the enctype attribute of the form has to be set to "multipart/form-data".
<form action="upload" method="post" enctype="multipart/form-data">
<input type="text" name=...
What is the difference between pluck and collect in Rails?
...ill only query the particular field. See this.
When you do:
User.first.gifts.collect(&:id)
You have objects with all fields loaded and you simply get the id thanks to the method based on Enumerable.
So:
if you only need the id with Rails 4, use ids: User.first.gifts.ids
if you only need ...
Is there a function to deselect all text using JavaScript?
...
Try this:
function clearSelection()
{
if (window.getSelection) {window.getSelection().removeAllRanges();}
else if (document.selection) {document.selection.empty();}
}
This will clear a selection in regular HTML content in any major browser. It won't clear a se...
Custom Python list sorting
...d takes optional arguments for controlling the
comparisons.
cmp specifies a custom comparison function of two arguments (list
items) which should return a negative, zero or positive number
depending on whether the first argument is considered smaller than,
equal to, or larger than the ...
Find an element in a list of tuples
...
If you just want the first number to match you can do it like this:
[item for item in a if item[0] == 1]
If you are just searching for tuples with 1 in them:
[item for item in a if 1 in item]
...
Value of type 'T' cannot be converted to
...
Even though it's inside of an if block, the compiler doesn't know that T is string.
Therefore, it doesn't let you cast. (For the same reason that you cannot cast DateTime to string)
You need to cast to object, (which any T can cast to), and from there to...
Convert data.frame columns from factors to characters
...
Just following on Matt and Dirk. If you want to recreate your existing data frame without changing the global option, you can recreate it with an apply statement:
bob <- data.frame(lapply(bob, as.character), stringsAsFactors=FALSE)
This will convert al...
When to use Preorder, Postorder, and Inorder Binary Search Tree Traversal strategies
I realized recently that while having used BST's plenty in my life, I've never even contemplated using anything but Inorder traversal (while I am aware of and know how easy it is to adapt a program to use pre/post-order traversal).
...
Get Android API level of phone currently running my application [duplicate]
...s various pieces of information about the Android OS a system is running.
If you care about all versions possible (back to original Android version), as in minSdkVersion is set to anything less than 4, then you will have to use android.os.Build.VERSION.SDK, which is a String that can be converted t...
How can I perform a culture-sensitive “starts-with” operation from the middle of a string?
... of many<->one/many casemappings first and separately from handling different Normalization forms.
For example:
x heiße y
^--- cursor
Matches heisse but then moves cursor 1 too much. And:
x heisse y
^--- cursor
Matches heiße but then moves cursor 1 too less.
This will apply to an...