java.lang.NullPointerException: Attempt to invoke virtual method on a null object reference
Your app is crashing at: because mPlayer=null. You forgot to initialize Player mPlayer in your PlayGame Activity.
java
Exception in thread “main” java.util.NoSuchElementException: No line found
The API document of readLine() method says as below You are supposed to handle this exception or just use the hasNextLine() method to avoid the exception.
Which HTML Parser is the best?
Self plug: I have just released a new Java HTML parser: jsoup. I mention it here because I think it will do what you are after. Its party trick is a CSS selector syntax to find elements, e.g.: See the Selector javadoc for more info. This is a new project, so any ideas for improvement are very welcome!
What is the significance of load factor in HashMap?
The documentation explains it pretty well: An instance of HashMap has two parameters that affect its performance: initial capacity and load factor. The capacity is the number of buckets in the hash table, and the initial capacity is simply the capacity at the time the hash table is created. The load factor is a measure of how … Read more
Lombok and Maven
This should work as is, and has nothing to do with IntelliJ idea. But I would: make sure the @Data annotation is the lombok one remove the repository definition (maven central is fine) use a recent lombok version (1.16.0 as of this writing) rebuild (mvn clean package) I think the lombok jar is not found by maven in … Read more
How to split a string in Java
Just use the appropriate method: String#split(). Note that this takes a regular expression, so remember to escape special characters if necessary. there are 12 characters with special meanings: the backslash \, the caret ^, the dollar sign $, the period or dot ., the vertical bar or pipe symbol |, the question mark ?, the asterisk or star *, the plus sign +, the opening parenthesis (, the closing … Read more
Double array initialization in Java
I was reading a book on Java and came across an example in which an array of type double was initialized in a way that I haven’t seen before. What type of initialization is it and where else can it be used?
how to iterate in List> in java and set their values as we do in a normal int a[i][j] matrix type [duplicate]
I think what you’re asking is how to do this: If you’re unfamiliar with lists in general, reading the answer here should provide valuable information on when to use which type of list
How can I properly compare two Integers in Java?
I know that if you compare a boxed primitive Integer with a constant such as: a will automatically be unboxed and the comparison will work. However, what happens when you are comparing two boxed Integers and want to compare either equality or less than/greater than? Will the above code result in checking to see if they are the … Read more