Java
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Java – how do I get a subclass recorder?
I have a subclass and a superclass In superclasses, I have a way to record something When I create an instance of a su…… -
Java – nested bounded wildcards
When I try to compile the following code: LinkedList<List<? extends Number>> numList = new LinkedList<L…… -
Java – vector graphics in IText pdf
We use iText to generate PDF from Java (based in part on the suggestions on this website) However, embedding an image …… -
Java – forces JTable to model “commit” data while still in edit mode
I have a JTable as follows Therefore, when JTable is still in edit mode (a keyboard cursor flashes in the divide colum…… -
Java – random and uniform distribution
I know that if I use the random generator in Java and generate numbers with nextint, the numbers will be evenly distri…… -
Java – what is the difference between length and length?
See English answer > length and length () in java7 arrayone.length; However, for things like array lists or strings…… -
How to get the root node attribute on Java
I have an XML file, as shown below I want to get the latitude and longitude attributes of the pharmacy node I can get …… -
Datetime – dome minutes using java 8
So I was lucky to use Java 8 and the new time API, but I didn't see any rounding function Basically, if the time is 20…… -
Java – spring security and LDAP authentication
I'm trying to set up LDAP authentication. This is my spring security XML file: <?xml version="1.0" encoding="UTF-8"…… -
Nesting enumerations in Java
I want to nest some enumerations The object I represent is flags, with type and value There are discrete types, each w…… -
Java – why does one loop throw a concurrentmodificationexception while the other does not?
I encountered this problem when I was writing a travel salesman plan For the inner loop, I tried one for(Point x:Array…… -
Cassandra Java driver: how many touchpoints are reasonable?
In Java, I connect to the cussandra cluster as follows: Cluster cluster = Cluster.builder().addContactPoints("host-001…… -
Java – why (long) 9223372036854665200d give me 9223372036854665216?
I know the strange things of precision error, but I can't understand it, Why did the (long) 9223372036854665200d give …… -
Java – hibernate noob fetch join problem
I have two classes test2 and test3 Test2 has a property test3, which is an instance of test3 In other words, I have a …… -
Java – mockito style anyxxx unit test method
When unit testing some methods, some situations may occur. The value of some parameters is not important and can be an…… -
Java – sqlitedatabase multi thread locking mode
I use this class to manage connections to the underlying SQLite database public class BasicDataSource { protected…… -
Java – string decoding UTF-8
How do I decode a UTF-8 string on Android? I tried to use this command, but output the same input: URLDecoder.decode("…… -
Java – transaction. In hibernate What is commit()?
transaction. What does commit () do? Account account = new Account(); account.setId(100); account = (Account) session.…… -
Java: the difference between collections and “data structures”
In Java, I don't understand the relationship between sets and "data structures" In my opinion, set refers to list, set…… -
Java – automatically generate source code and document jars in NetBeans
Is there any way to automatically generate source code and Javadoc jars in NetBeans? Ideally, I want to put my source …… -
Java – the contents of the window disappear when minimized
I have a simple class that draws a line when the mouse is dragged or a point when the mouse is pressed (released) When…… -
How to extract dates from UUIDs using Java?
How to convert UUID to date format 2011-04-22? For example, I have such a UUID 118ffe80-466b-11e1-b5a5-5732cf729524. H…… -
Java – ArrayList warning- warning:[unchecked] does not select Add (E), nor does it run the file. Please help?
I've been trying to make this code feel like an era at this stage It is to calculate prime numbers in a range, and I h…… -
How to use java code to find the distance between two Zipcodes?
My request is similar to this question, except for the fact that I am prohibited from using latitude and longitude val…… -
Java – delete elements from copyonwritearraylist
I received an exception when I tried to delete an element from copyonwritearraylist using an iterator (from http://dow…… -
Java – how to get offline tokens and refresh tokens and automatically refresh access to Google APIs
I am developing an application that uses oauth2 and Google client library (located in appengine and GWT btw) to access…… -
Using javax Tool for cascade memory compilation
Eclipse's JDT compiler provides an interface inameenvironment, which defines the method findtype (...), enabling you t…… -
Sparksql and explode on dataframe in Java
Is there a simple way to use array column explosion on sparksql dataframe? It's relatively simple in Scala, but this f…… -
Java – HashSet adds duplicate entries, although hashcode() and equals() are implemented
I have the following categories: class Point { double x,y; // .... constructor and other functions here …… -
Java – how to resolve conflicting attributes if multiple profiles are activated
Maven profiles documentation does not mention this, which may be a sign of wrong design in the construction process, b…… -
Java – convert a triangle to another triangle
Hi, I'm trying to create an affine transformation, let me turn one triangle into another I have the coordinates of two…… -
Java – why does TreeSet throw ClassCastException
In the following code, I try to add two employee objects Set<Employee> s = new TreeSet<Employee>(); s.add(……