I’m trying to run DMelt programs (http://jwork.org/dmelt/) program using Java9 (JDK9), and it gives me errors such as: How can I fix it? I was trying to add –illegal-access=permit to the last line of the script “dmelt.sh” (I’m using bash in Linux), but this did not solve this problem. I’m very frustrating with this. I … Read more
Of course the “You shall not instantiate an item of this class” statement has been violated, but if this is the logic behind that, then we should all throw AssertionErrors everywhere, and that is obviously not what happens. The code isn’t saying the user shouldn’t call the zero-args constructor. The assertion is there to say that as far as … Read more
In Java, What exactly is Parsing? Why are they used? For example: Integer.parseInt(…), and parsing a string?
// index.jsp In backend.jsp what does request.getParameter(“one”); return? request.getParameter(“one”).getClass().getName(); returns java.lang.String, so it must be a String right? However I cannot do or This is obvious, because variable one does not return null. Is only way to go, or are there better solutions or a better approach? I am considering both solutions to be on … Read more
On a Mac, by default, mysql is installed to /usr/local/mysql/ The path to the binaries (mysql, mysqladmin, etc.) should therefore be /usr/local/mysql/bin
If you try to decrypt PKCS5-padded data with the wrong key, and then unpad it (which is done by the Cipher class automatically), you most likely will get the BadPaddingException (with probably of slightly less than 255/256, around 99.61%), because the padding has a special structure which is validated during unpad and very few keys … Read more
Cloning the objects before adding them. For example, instead of newList.addAll(oldList); Assuming clone is correctly overriden inPerson.
You can try using System.arraycopy() But, probably better to use clone() in most cases:
A nice way to do this is using Apache commons IOUtils to copy the InputStream into a StringWriter… something like or even Alternatively, you could use ByteArrayOutputStream if you don’t want to mix your Streams and Writers
The two operands (1 and 3) are integers, therefore integer arithmetic (division here) is used. Declaring the result variable as double just causes an implicit conversion to occur after division. Integer division of course returns the true result of division rounded towards zero. The result of 0.333… is thus rounded down to 0 here. (Note that the processor … Read more