Java
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Certification – Java – pbkdf2 and hmacsha256 as PRF
I was given the task of creating a login API for our project. I should use pbkdf2 and hmacsha256 as PRF The plaintext …… -
Java – error: unable to determine the type parameter of T during Maven installation
I have this feature that throws strange errors when I try to do an "MVN installation" public <T> T get(final AN_…… -
Java – dump the state of a variable in case of an exception
I want to know if there is a way to dump the state of all local variables when an exception occurs, so as to better un…… -
Java – use request Getsession () as the lock object?
I have some java code to get and set a session property: Object obj = session.getAttribute(TEST_ATTR); if (obj==null) …… -
Java – ArrayList containing different objects of the same superclass – Methods for accessing subclasses
Hi, I want to know if there is a simple solution to my problem, I have an ArrayList: ArrayList <Animal> animalLi…… -
Java – how to inject beans into ApplicationContext before loading from a file?
I have a filesystemxmlapplicationcontext. I want the bean defined in XML as a constructor parameter, a bean that is no…… -
Java expression compilation error
See English answers > why is n + + + n valid while N + + + n is not? one int x=-3; System.out.println(x-----x);…… -
java – Short toHexString
There is a method integer Tohexstring() and long toHexString(). For some reason, they did not implement short toHexStr…… -
Java – save treeviewer state before setinput()
I tried to save the Jface treeviewer extension state to refresh it after calling the setinput () method I tried the se…… -
Java – spring – constructor injects and overrides the parent definition of nested beans
I read the resources for spring 3 in inheriting bean definitions, but I'm confused about what's possible and impossibl…… -
Java – compare and exchange
As the title indicates, I am looking for a comparison and exchange implementation, but it is relatively large: if(newV…… -
Java – how to initialize BigInteger after creating an instance (constructor cannot be called)
Imagine an instance of BigInteger, so how do you initialize it after you create it? For example: BigInteger t = new Bi…… -
Java – interfaces and concrete classes
Below I have a person interface, an implementation class and a driver class, which initializes person with a name and …… -
Java – create a directory, if it does not exist, and then create the files in that directory
The condition is that if a directory exists, you must create files in that specific directory and create a new directo…… -
Using “forbidden” classes in Java?
My employer needs an extension org eclipse. rse. core. subsystems. The Java class of subsystem for eclipse plug - ins …… -
Java – use the super keyword in subclasses to access private fields of superclasses
For coding projects, I have a class that contains nested classes Nested classes subclass in the same external class It…… -
Java – generics and classes >, EnumSet. allOf(class)vs class. getEnumConstants()
I have the following beanvalidation code that works properly and allows you to validate a bean annotation with: @EnumV…… -
Java – jcombobox itemstatechanged event is called twice at a time
@H_ 419_ 2@resultCombo = new JCombo@R_611_2419 @(); resultCombo. addItemListener(new ItemListener() { @Override public…… -
Java annotation values are provided dynamically
I want to provide comments for some values generated by some methods I've tried so far public @interface MyInterface {…… -
Java – passing subclass instances as superclasses using JAXB
I have a set of Java classes representing message types (close to 25) They all inherit the message class that they wan…… -
Java – is it OK to add the default implementation to the method representing the listener’s interface?
A library is used in my project This library has an interface with about 15 methods The purpose of this interface is t…… -
Strange default method behavior with different Java versions
Suppose I have the following class hierarchy: interface Collection<E> { Collection<E> $plus(E element)…… -
Java – annotation processor – how to get the class it is processing
I'm trying to write a custom annotation processor public class AnnotationProcessor extends AbstractProcessor { .....…… -
How do you feel about JavaFX?
I have done a lot of work in ActionScript 3.0, and I also like programming in Java Is JavaFX right for me? What is the…… -
Java – what happens to its iterator when I sort a list?
Suppose I have a list object and an iterator for that list Now I use Java util. Collections. Sort() sorts the list >…… -
java – Thread. Getid() global uniqueness problem
If multiple Java applications are running on the system, each thread ID is unique relative to all other Java threads, …… -
Java – could ThreadLocal be useful?
So I just saw someone try to use a ThreadLocal < atomicinteger > in some java code And it always seems useless: …… -
java – WebSphere 7. Inject EJBs from another application
I tried to inject EJB with @ EJB annotation: >When I inject an EJB into another EJB in the same ear, it works norma…… -
Java – dynamic change persistence unit – JPA
persistence. The persistence unit in XML is created during the construction of the application Since I want to change …… -
Zero padding and left padding integers in Java (non decimal format)
Has been answered for integers printed in decimal format, but I'm looking for an elegant way to do the same with integ…… -
Java – unable to create eclipse data source to Oracle 12C. Jar But 11g’s work
When I open the data source Explorer window and try to create a new connection profile, I select "oracle", Oracle thin…… -
Java GetClass () returns a class. How can we get a string?
When I use system out. Println (obj. Getclass()) it doesn't give me any errors Return a class type from getClass () as……