Java
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What is the guarantee of generic drugs in Java?
Although I know, generics are used to make our code more general and flexible But what is the guarantee of cast iron i…… -
Why does Java forkcomb not cause stackoverflowerror?
I'm a new programmer. I'm trying to teach myself what causes stackoverflow I play with loops and cause errors, but the…… -
Java: large integer error
I want to use the following mathematical formula in Java: (44334*(220*220))+ (81744*220) + 39416) When I enter the sam…… -
Java – load using applet DLL and use it on the client
I can load from the server to the client in the applet, and then call the load on the client DLL (using JNI)? Solution…… -
Java regular expressions remove SQL comments from strings
I hope someone can help me solve this problem! I have an SQL file that looks like this: CREATE TABLE IF NOT EXISTS use…… -
Java – Convert byte array to double array
I encountered some problems with WAV files in Java WAV format: PCM_ Signed 44100.0 Hz, 24 bit, stereo, 6 bytes / frame…… -
Java – use generics to return multiple types
I have this method – public List<Apples> returnFruits(String arg1){ List<Apples> fruits = new ArrayList<…… -
Java – do we have all the original types of pools in the permgen area of the heap?
I know the concept of string pool in permgen area of heap So when we do something like this String firstString = "Stac…… -
Java: how to communicate with multiple clients in a single thread
I have a list of sockets belonging to a single thread But I wonder if there is a feasible way to communicate (read / w…… -
Dropwizard / Jersey returns the Java list as JSON without a root node
I'm using the dropwizard using plain knit fabric for Jason My problem is that when I return a list, it does not specif…… -
Java – XML error due to servlet file. The declaration of the element cannot be found, and the referenced file contains an error
I don't know why these mistakes happen. Someone can explain how I solve them – > cvc-elt. 1: Element 'Web' not foun…… -
Java – HibernateException: the proxy handle is no longer valid after the database violation error
I have a loop to hold several objects Invoke the service method in the loop and catch the exception. The service saves…… -
Java – how to programmatically launch Apache Derby jar files?
I have a Java application that uses Apache Derby Using the eclipse export option, I export it as a jar file When I run…… -
Java – OOP design – Private modifier
I thought I knew when to use the private keyword Encapsulation is the reason for this, so I try to keep all methods as…… -
Java – @ entity entity cannot be resolved to a type
Learn spring MVC and hibernate import javax.persistence.Column; import javax.persistence.GeneratedValue; import javax.…… -
Java character set / character encoding
I have a Spanish file, so it is full of the following characters: á é í ó ú ñ Ñ Á É Í Ó Ú I have to read the document,…… -
Java – how to wait for all callables to complete execution before continuing?
I have the following hash code: public class MyCallable implements Callable<Long> { @Override public Lon…… -
Loop stop Java
For the following code, when "n" is about 100000, it will stop running I need it to run to a million I don't know what…… -
Java – JNI local reference table summary (512 entries)
I have more than 10000 city names that I want to display in listview I store these names as cities in the RES / values…… -
Java monitoring: JMX and servlets
In the past few years, I have learned a lot about JMX and built some very beautiful MBeans for my web applications But…… -
The try catch block cannot suppress Java lang.NullPointerException
I got Java Lang.nullpointerexception, I don't know why I tried to use the try catch block, but it didn't work Can anyo…… -
How to compare two string arrays without Java utils
Check whether array Arr1 contains the same elements as arr2 in the same order in Java For example: isTheSame({"1","2",…… -
Java Swing: add jlabel to JPanel
I just want to add jlabel to the existing JPanel It looks simple. I searched everywhere I think this is right, but the…… -
Hexadecimal enumeration types use java to return wrong values?
I use the following enumeration types in the following code: public static enum PanelType { PAS8((byte)0xA6),PAS83…… -
Java – concurrent HashMap document description
Concurrent HashMap is fully interoperable with hashtable in programs that depend on its thread safety but not on its s…… -
Correcting Java program code snippets
I'm a beginner. I learn Java and modify my exam by answering the questions in the past exam papers. There's another qu…… -
Set vs alphabetical order in Java list
Arent lists ordered collections and is not ordered? So why does this program sort strings alphabetically instead of li…… -
Java – arrange swing components by edge
Can swing components be arranged? You can see a subtle difference that I find very annoying I know that all jlabels [B…… -
Java Object. equals
Can someone tell me why this returns true? Please tell me under which topic I can find more information about this beh…… -
Java observer update function
I have a class that implements the observer. Of course, it needs to have the update function: public void update(Obser…… -
Java – common code when rewriting abstract methods – Design Problems
I have an abstract class like this public abstract Stuff { public abstract void doStuff(); } Several classes are e…… -
Improve performance when working with images in Java
I'm writing a program that includes an image folder (usually about 2000 JPEG images) to resize them and add them to th……