Java
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Java – JIT optimization and weak references
I have the following code: private final List<WeakReference<T>> slaves; public void updateOrdering() { …… -
Why is the scope of switch statements in Java unlimited?
Why in Java, the scope of variables is limited to switch blocks rather than case blocks For example, // Scope limited …… -
java – SimpleDateFormat. Parse () – generates incorrect dates for different date formats
Here is my code for parsing dates using the simpledateformat pattern: String pattern = "yyyy-MM-dd"; SimpleDateFor…… -
Java – how to make good GUI design in swing
Hello stackoverflow family I developed a Java Swing application, but I want to improve the design of my swing framewor…… -
Java – spring rest security – protects different URLs in different ways
I use the rest API for basic authentication under spring 4 These rest services are located under / API / V1 / * * URL …… -
I shouldn’t do ` string s = new string (“a new string”)` In Java, even automatic string practice?
Well, this problem is an extension of this problem Java Strings: “String s = new String(“silly”);” The above question …… -
Java – order of static initialization blocks
I found a lot of posts on the static initialization block, but I tried to better understand the execution order and wh…… -
Is there a ‘checked’ keyword equivalent to c# in Java?
Yes, this is a very simple piece of code, but I still want to know if there is a built-in alternative This is the code…… -
Java – unable to connect to SQL Server database using JDBC
I am trying to connect to an existing database in SQL Server 2012n using NetBeans 8 Using the connection wizard, I sel…… -
Why is the runtime exception “unchecked” in Java?
Why are runtime exceptions unchecked meaningful (not if they are checked)? Solution If you do not, you must use the tr…… -
Swing – why does eventlistenerlist traverse backwards in firefooxxx()?
I don't understand the basic principle of this code, which is taken from javax swing. event. Eventlistenerlist documen…… -
Java – regular expression patterns match all uppercase letters after colons
I need a pattern that matches words like apple: or pear: [A-Z] [:] will match R: but not the whole word, so it will gi…… -
Java – Jackson, serializing a referenced attribute
When serializing Java objects with other object references, I only need to serialize one attribute of the nested objec…… -
How to create a reordering tableview in JavaFX
I have a JavaFX tableview I want to allow users to click and drag to reorder table rows I can't seem to find any way t…… -
How to use webdriver selenium to get the value of the “style” element
I want to check whether the value of a style element is greater than a specific value (that is, is it > 666px?), Bu…… -
java. Lang. class and equal
According to the Javadoc of the class But when I ran down there int[] intArray = { 1,2 }; out.println(intArray.getClas…… -
Java – set the most important bit by bit
I want to find the most important bit set to 1 I've tried all possible ways from & oring all bits from 1 to 31, it…… -
Java – how to generate an IP address range given the start and end IP addresses?
How do I generate a series of IP addresses from the start and end IP addresses? Network example "192.168.0.0/24": Stri…… -
Java – should I always use generics?
I created a unit test: new Callable() { @Override public Object call() throws ..... I received a warning in E…… -
Java – invariance and readability
So I have been reading effective java written by Joshua Bloch and noticed two points I encountered in my work Point 1:…… -
Close the Java program correctly when jdialog is the main window
I have a jdialog as the main window in my application (initially it was a JFrame, but it showed in the taskbar that I …… -
Java – how to split without regular expressions
In my java application, I need to use the same "target" to find the index and split the string in both cases The goal …… -
Layout – how do I get the buttons to populate the JavaFX gridpane?
Java swing has a GridLayout that allows you to specify the size of an array of widgets, such as 3x4 The widgets then p…… -
Java – improved main screen algorithm
I'm trying to make a good java program to generate prime numbers from 1 to n (mainly for project Euler problems) At pr…… -
Java – null is a good way to check a long list of parameters
Suppose that all parameters of the same type for some methods are long I have similar operations on each parameter (if…… -
Generate Java dump when OUTOFMEMORY
I have a program that should eventually generate OUTOFMEMORY public class VeryLargeObject implements Serializable { …… -
Java – mockito throws an outofmemoryerror in a simple test
I try to use mockito to simulate the database pool (only for retrieving data), but it will run out of memory when runn…… -
Java gets the file extension without substring
How to get a file extension in Java without using stupid lastIndexOf ('.') and so on? Solution The Apache commons libr…… -
Java – get button name from actionlistener?
I have browsed the Internet, but I can't find the answer I am using the for loop to create 36 buttons called A1, A2, e…… -
Why does Java’s schedulewithfixeddelay use runnable instead of futuretask Packaging runnable?
Why does Java's schedulewithfixeddelay use runnable instead of futuretask to wrap runnable? It can be easily displayed…… -
Java: scheduling tasks at random intervals
I'm new to Java. I'm trying to generate a task that runs every 5 to 10 seconds, so any time interval between 5 and 10,…… -
Java – using the comparable vs TreeSet list
Option 1: create a list that implements comparable and use collections. Net each time you add a value Sort (List L) so……