Mergesort in java

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I am new to Java and have tried to implement mergesort in Java. However, even after running the program several times, instead of the desired sorted output, I am getting the same user given input as …

Many to many with Hibernate and annotations for self referencing

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My brain is starting to hurt thinking about this, is it as simple as: @ManyToMany(mappedBy = “following”, cascade = CascadeType.ALL) private Set followers = new HashSet(); @…

Tags: any java set

Good way to get *any* value from a Java Set?

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Given a simple Set, what is a good way (fast, few lines of code) to get any value from the Set? With a List, it’s easy: List things = …; return things.get(0); But, with a Set, …


implementing a lazy Supplier in java

What is the right paradigm or utility class (can’t seem to find a preexisting class) to implement a lazy supplier in Java? I want to have something that handles the compute-once/cache-later behavior …


Get Username from Amazon Access Key in Java

Is there a way to get the User Name attached to the Access Key for the credentials you’re using to access AWS via Java? I would like to be able to get the User Name that’s defined in the IAM Users …


How to Check if A Git Clone Has Been Done Already with JGit

I learning git and using JGit to access Git repos from java code. Git by default does not allow to clone to a non-empty directory. How do we figure out that a git clone has already been done for a …

Size of byte array gets double when it retrieve from Postgres database

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I am using JSF2.0, jetty server and Postgres database. I want to store mp3 file in database in byte array formet. I upload the byte array of mp3 file. But when I retrive same byte array from database …

How to parse a String variable into any data type in Java?

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I want to build a method that can convert a String value to a given Field object data type through Java Reflection. Here is my code: String value = …; Class clazz = …

How to match any combination of letters using regex?

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How can I match letters a,b,c once in any combination and varying length like this: The expression should match these cases: abc bc a b bca but should not match these ones: abz aab cc x

JFileChooser change default directory in Windows

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I want to change the default directory of my JFileChooser to “My Music” on Windows. This directory is C:UsersFreMusic on my account because my username is Fre The default is set on C:UsersFre…