I’m trying to use prepared statements to set a table name to select data from, but I keep getting an error when I execute the query. The error and sample code is displayed below. Any thoughts on what might be causing this? Answer A table name can’t be used as a parameter. It must be hard coded. So…
Tag: java
How to encrypt String in Java
What I need is to encrypt string which will show up in 2D barcode(PDF-417) so when someone get an idea to scan it will get nothing readable. Other requirements: should not be complicated it should not consist of RSA, PKI infrastructure, key pairs, etc. It must be simple enough to get rid of the people snoopin…
Shrinking an ArrayList to a new size
Do I really need to implement it myself? Answer Create a sublist with the range of elements you wish to remove and then call clear on the returned list. This approach is mentioned as an idiom in the documentation for both List and ArrayList. Here’s a fully unit tested code example!
How do I print the class structures in a jar file using the javap tool?
I want to list the methods of the class files in the jar using the javap tool. How do I do it so that it lists the methods and members of all the class files in the jar. Right now I am able to do it for just one class at a time. I am expecting something like if I
What is the simplest way to convert a Java string from all caps (words separated by underscores) to CamelCase (no word separators)?
The title pretty much says it all. What’s the simplest/most elegant way that I can convert, in Java, a string from the format “THIS_IS_AN_EXAMPLE_STRING” to the format “ThisIsAnExampleString”? I figure there must be at least one way to do it using String.replaceAll() and a regex.…
How to escape a square bracket for Pattern compilation?
I have comma separated list of regular expressions: I have done a split on the comma. Now I’m trying to match this regex against a generated password. The problem is that Pattern.compile does not like square brackets that is not escaped. Can some please give me a simple function that takes a string like…
How to rotate text in a spreadsheet cell using Apache POI?
How can I rotate the text within an HSSFCell class of Apache POI? Answer Use HSSFCellStyle, that class has a method called setRotation(short rotation) which will rotate the text. All you do is apply the cell style to a cell:
Making a JPanel manually resizable
I have a JFrame with BorderLayout as the layout manager. In the south border, I have a JPanel, I want this JPanel’s size to be adjustable by the user, i.e. the user can click on the edge of the border and drag it up to make it larger. Is there any way you know that I can do this? Answer
Determine the size of an InputStream
My current situation is: I have to read a file and put the contents into InputStream. Afterwards I need to place the contents of the InputStream into a byte array which requires (as far as I know) the size of the InputStream. Any ideas? As requested, I will show the input stream that I am creating from an upl…
How to display X-Bar statistics symbol in Java Swing label?
What’s the best way to insert statistics symbols in a JLabel’s text? For example, the x-bar? I tried assigning the text field the following with no success: Answer Html codes will not work in Java. However, you can use the unicode escape in Java Strings. For example: Also, here is a cool website f…