Java
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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(…… -
Is the Java – VIM editor smart?
I program in C or Java So I want to use the VIM editor because it is very flexible I heard I can configure the VIM edi…… -
Java anonymous classes and synchronization and “this”
I'm dealing with a competitive condition that I believe in my java GUI I have some methods to create an "anonymous met…… -
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 – Tomcat can’t find my servlet and throw an exception, but why?
I tried to get into Java Web development, but it seems to be running into a strange problem with Tomcat and a very sim…… -
@Elementcollection Java persistence (hibernate) causes duplicate instances to be loaded
When @ elementcollection is used, multiple instances of all objects being loaded are loaded More specifically, it is l…… -
Is there a quick way to convert Java XML objects to scala XML objects?
Scala has its own XML library and provides built - in support However, one of the main features of the language is cal…… -
Java – lists and lists
Why lose type security when using list and use list < Object >? Aren't they basically the same? Editor: I found …… -
JPA – @ onetoone unidirectional and bidirectional
I have two examples, the first is @ onetoone one-way mapping and the second two-way mapping In one-way mapping, the ow…… -
Java – JPS cannot connect to remote jstatd
I'm using jstatd to query a remote JVM using JPS so that I can eventually monitor it using visual VM I use jstatd to r…… -
Java – create a command console
I have an unusual question: how to use swing to create a "command console"? What I want is the console where the user …… -
Java – default timeout for httpcomponent client
I can't find any documents on the default httpparams of httpclient 4.1? What is the default socket timeout when I do a…… -
Java – type A has defined an error
I tried to search for a solution, but I found that I didn't know how to apply it in this case Please help me correct m…… -
Java – how does akka implement the relationship before JMM?
In the official akka document, they refused: For details, please refer to the doc I wonder how akka did it I just pass…… -
Java – incompatible types and fresh type variables
I get the following compilation message: [javac] ... error: incompatible types [javac] exceptionClassHolder …… -
JavaFX – how to make ComboBox hgrow?
I have JavaFX (8), H@R_509_2419 @, Combo@R_509_2419 @And hgrow This is my fxml Code: <?xml version="1.0" encoding="…… -
Java – you can mark interfaces, such as serializable, which contains default methods?
I don't think it can, because the principle of markup interface is that there is no method, but I don't know because t…… -
Java – should you report the message text of the exception?
Consider some code that can throw a check exception (an exception of type exception) Of course, your code catches exce…… -
java – Make Enum. Tostring() localization
I'm developing an Android application and I want to know if I can set enum Tostring() multilingual I'll use this enume…… -
Java – when to use servicetracker and servicereference
I've just started using OSGi programming, and I've encountered two ways to listen to activated services The first meth…… -
Parallelism and plan view in Java 8 streams
Hey, I have a problem with parallelism when I use flatmap IntStream.of(-1,1).parallel().flatMap(i->IntStream.range(…… -
Java – why do you get a NullPointerException when comparing a string with null?
My code uses NullPointerException to break in the following line: if (stringVariable.equals(null)){ Before this statem…… -
java – com. w3c. dom. Document does not have
I'm using the following code to create com. Com from string w3c. dom. Document： DocumentBuilderFactory docFactory = D……