Java
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Java string to int
I have a string of about 150 numbers, such as string num = "64513246563....."; I'm trying to add every number of this …… -
Java – if (pause = = null) {does not work
When pause is null, I use if (pause = = null) to perform some operations But I made a mistake For parameter type long,…… -
How to use equalsignorecase() for multiple elements in Java
if(string.equalsIgnoreCase("first") || if(string.equalsIgnoreCase("first") || string.equalsIgnoreCase("second") || s…… -
Java – traverses the array in reverse without minus sign
I was asked this question in today's interview I'm sure it's a very simple technique, but I can't think of it How do I…… -
Java – sort a list of non comparable elements
Today, I was asked this interview question: I know I need to make the person class implement comparable and then overr…… -
Are there tools for documenting Java applications?
I wonder if there is a tool for recording Java applications I mean, if I want to specify in my code what each function…… -
How to set the first day of the week in a Java application calendar
We use a Java application that has a date selection field when you click there to open a small calendar The first day …… -
Java – strange null pointer exception: ternary conditional operators do not use string concatenation
StringBuffer sb=null; StringBuffer sb=null; // Some more logic that conditionally assigns value to the StringBuffer …… -
Java recursive insertion sort?
So I tried to turn the following code into a recursive method to insert sorting, but although I tried, I couldn't Who …… -
Java – why doesn’t my JFrame display?
I'm trying to display a solved Sudoku puzzle in a window with 81 boxes I did this: import java.awt.GridLayout; import …… -
Java – create treemap visualization
I want an algorithm for creating treemap visualization Like this: an easy way to make a treemap The problem is that I …… -
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Java – reproduce simpledateformat non thread safety in testing
I have an application that has this stack trace in the log from time to time: java.lang.Arrayindexoutofboundsexception…… -
Java – an alternative method to compare three ints for equality
int a = 10; int a = 10; int b = 10; int c = 10; I tried to find out if there was an alternative way to compare three i…… -
java – fragment_ display_ Message: My First Android application error
This is my first time developing mobile applications Environment: Eclipse Kepler, Java 1.7 backend: I follow these ste…… -
Java – cannot convert generic set?
I have an interesting problem today Consider the following code public static class Parent {} public static class Chil…… -
Java – good UI Design: how to handle empty listview?
My application connects to the network and populates listview Sometimes nothing is returned What is the best way to no…… -
Java – learn about ArrayList indexoutofboundsexception in Android
I get a lot of indexoutofboundseception from any ArrayList I use Most of the time it works, but sometimes I encounter …… -
Java – can any unused object escape from the garbage collector?
Are there any objects that may not be referenced anywhere and still exist on the heap I mean, an unused object may esc…… -
Java – JSTL and time zone
I have some questions about the time zone We store all dates in UTC time, but we need to display some of them both in …… -
Java code optimization, it will optimize this
For newer compilers, I find myself trying to write more readable code, but if the optimization I want to do under the …… -
Java – Android: how do I get two digits after a decimal value? Do not want to truncate the value
How to get a double precision value with only two digits after the decimal point For example, if a = 190253 8084615384…… -
Java exception handling?
The following code calculates the average of the numbers stored in the text file Solution If necessary, you can use Ja…… -
Java – how to operate on large numbers that cannot be stored in a variable
In Java, I want to be able to operate on very large integers (which cannot be stored for a long time). What should I d…… -
Java – use check boxes to wrap text in a text area
I created a dialog box for editing data in swing It contains a jtextarea, two JButton instances (OK & cancel) and …… -
java. lang.OutOfMemoryError：
I'm trying to create a video file from the bytes retrieved from the database The plan worked well a few hours ago Afte…… -
Java – intelligent garbage collection?
You simply call system GC () can do garbage collection in Java, but sometimes this "delays" the application Collecting…… -
Java – can each thread have a unique static variable?
I have a static variable and I want each thread to be unique Is this the case with all static variables? Or there is n…… -
Java – enabling websecurityconfigurer via @ profile does not work
I think I have a very simple and basic setup for running spring boot webapp with some authentication locally I hope th…… -
What is the best way to use hibernate’s detachedcriteria to limit results in Java?
I use hibernate 3.5.0 in Java 6-Final. Because I can't access hibernate session, I use detachedcriteria So, I want to …… -
How to resolve file names in Java?
I have a java file path /opt/test/myfolder/myinsidefolder/myfile. jar I want to replace the file path with the root pa…… -
Java – how to add padding using container?
I tried to do some padding at the top, but how do I use the container? JFrame frame = super.screen.getFullScreenWindow……