Java
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Java – Android replaces multiple characters from a string
I know it may be an amateur problem, but for some reason, I don't remember how to do it String s ="["; String q ="]"; …… -
Is the result of mathematical operation on Java – double completely repeatable?
I have a complex data processing algorithm, using java 8 and double as the data type Given the same input (hundreds of…… -
Java — on doubles and equality
I have a method that returns a double When I tested this method as part of JUnit, I noticed the following oddities: St…… -
Java – is an if else tree the best approach in the following situations?
What am I doing: I'm creating a simple calculator in Java that reads a string written in postfix notation (for example…… -
Thread problem in Java HashMap
Something happened that I'm not sure should work Obviously it's because I've seen it, but I need to find the root caus…… -
Java – a naming convention for variables that work like constants
I have a variable that I'm using like a constant (it never changes) I cannot declare it as a constant because the valu…… -
Where can I find Java main functions
Is public static void main (string [] args) a built-in or user-defined or overridden function of some classes provided…… -
Java – how to avoid instanceof calls?
I defined this simple method: public static boolean isBorder(int x,int y) throws CollisionDetectionException { …… -
Java – what is system in
Consider this scanner input example Scanner user_input = new Scanner( system.in ); The scanner is class user_ Input is…… -
Java string Split() deletes trailing empty entries
I'm trying to parse some pipe delimited records I have this Code: public class Test { public static void main(Stri…… -
Inconsistent Java performance
I have an interpreter written in Java I tried to test the performance results of various optimizations in the interpre…… -
Can Java 10 compiled classes run on 9?
See the English answer > can Java 8 code be compiled to run on Java 7 JVM? 5 Is my hypothesis correct? Solution Thi…… -
How to use file. XML in Java Mkdirs () writes elegant code?
I need a directory to save the file, but I'm not sure if it exists File saveDir = new File("/tmp/appname/savedir/"); i…… -
How do I embed java code in JSF pages?
I have: In this JSF page, I have a login form Inside the managebean, I have a logincheck function public void loginChe…… -
Java – optimal solution of maximum single sales profit algorithm
The input array is: A[0] = 23171 A[1] = 21015 A[2] = 21123 A[3] = 21366 A[4] = 21013 A[5] = 21367 The mission is t…… -
Java generic problem
Can I write a method that can create an instance of any specified type? I think Java generics should help, so it might…… -
Java 8 avoids a large number of if / else statements
I have something that looks like this: public boolean isValidObject(SomeObject obj){ if(obj.getField() == null){ …… -
Use AutoCAD Library in Java to read DWG file?
Are there any open source Java or JavaScript libraries available for parsing DWG file and get objects from it I want t…… -
Java for loop problem
I'm making a java program to calculate Simpson's integral rules This is my code Note the second column of numbers in t…… -
C command line strings like Java?
Is there any way to get the C string from the command line, just like in Java? public static void main(String[] args) …… -
Deprecated in Java 1.6
In Java 1.5, to discard a method, you will: @Deprecated int foo(int bar) { } Compiling in Java 1.6 results in the foll…… -
Java – a simple leap year logic problem
public class LeapYear { public class LeapYear { public static void main(String[] args) { int year = Int…… -
Java – how to print arrays easily?
See English answer > What's the simple way to print a Java array? 32 System.out.print("["); for(int i = 0; i < a…… -
Java – reverse loop for array countdown
I received an error Exception in thread "main" java.lang.Arrayindexoutofboundsexception: 10 at Reverse.main(Revers…… -
Check the existence of Java in the file
I want to create a text file, but if the file already exists, I should not create a new file, but attach the text to t…… -
Java – load the keystore on OSX lion from the file created using keytool
I have a keystore whose key pairs are generated by the following command: keytool -genkeypair -v -alias test-agent -ke…… -
How to generate random numbers using Java in a given number list
Suppose I have a number / vector number, such as 1,3,7,9, and then I need to guess the number in this list at random U…… -
Java – business logic of the client
Why do people say that business logic should be implemented on server-side code (such as EJB) rather than on client-si…… -
Why does BigInteger’s stackoverflowerror in Java end up as an integer in the 19635th Fibonacci sequence
I use the following code to calculate the Fibonacci sequence to any large number The code worked as expected until I a…… -
Java – find the largest palindrome made by the product of two 3-digit numbers
package testing.project; package testing.project; public class palindromeThreeDigits { public static void main(S…… -
Java – when comparing two equal integers in a while loop, does the equal operator fail?
I post two examples below Example 1: Integer myVar1 = 42985; Integer myVar2 = 1; while (true) { if (myVar2 …… -
Java regular expression performance
I'm trying to parse links with regular expressions in Java But I think it's getting too slow For example, to extract a……