Java
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Java – accessing private fields of another object in the copy constructor – is that really a problem?
In my java application, I have some such copy constructors public MyClass(MyClass src) { this.field1 = src.field1;…… -
Java – missing preview tab in birt layout
A new version of birt 4.0 has just been installed in eclipse x. The preview tab was not found in the layout window Sol…… -
Fast and constant get () mapping with Java 7
When using the HashMap provided by Java 7, I encountered a problem, that is, get() evolved from O (1) to o (n), as des…… -
Java – what makes HashMap Putifabsent is faster than containskey?
topic How can the HashMap method putifabsent conditionally execute put faster than before calling containskey (x)? For…… -
Java – anonymous variable (?) Advantages?
I want to know something suddenly came to my mind yesterday We can do this (in Java): ObjA instanceA = new ObjA(); Obj…… -
Java – use beans to send mail from JSF pages
I am using JSF and primefaces to create a web application. My problem is how to send e-mail through the contact form o…… -
JavaFX 8 datepicker function
I just started using the new JavaFX 8 control datepicker In datepicker user experience documentation, it claims that i…… -
How do you use CouchDB change notifications to make continuous changes from Java?
I'm trying to use CouchDB (continuous) change API in Java and find that after exhausting the current change list, the …… -
Java – how do I manage optional spaces in ANTLR?
I tried to parse the data file in ANTLR – it has optional spaces 3 6 97 12 15 18 The start and end positions of t…… -
How do I inform users that a specific tab in jtabbedpane needs attention?
Suppose you have a user interface with five or more tabs and you need to notify the user that tab "2" needs attention …… -
Java – change date format
If the input is 01-01-2015, it should be changed to 2015-01-01 //Class to change date dd-MM-yyyy to yyyy-MM-dd and vic…… -
How to protect methods in Java (overflow, etc.)
I have to write a "watchdog" in Java to ensure that threads do not take long to execute There is no problem with objec…… -
Java – I can have the ArrayList string in the realm object Android
Since we don't have any list data types in the domain, how can we use ArrayList < string > to create objects in …… -
Java – use transferhandler to drag jlabel (drag and drop)
I'm using the transferhandler to transfer data from JPanel to jtextarea as a jlabel (click somewhere in the left panel…… -
Java – generic type parameters depend on itself
I encountered the following situations: I understand this: In the type parameter part of the class, if s is the bounda…… -
Java – Apache beam – integration test of unbounded pcollection
We are building integration tests for the Apache beam pipeline and have encountered some problems For background infor…… -
Java – Android Google Maps V2 – SD card as tile provider
I am using Google Maps API V2 to develop an Android application. I have to use offline tiles. I have all tiles of the …… -
Add two vectors by name
I have two named vectors v1 <- 1:4 v2 <- 3:5 names(v1) <- c("a","b","c","d") names(v2) <- c("c","e","d") I…… -
Java – checks at run time whether a class has a specific constructor that uses generics
Hello:) I'm trying to choose the correct constructor in the class This is the code: Constructor[] constructors = targe…… -
Java – JPA – delete children from the onetomany relationship
In the @ onetomany relationship, if I want to delete a child, do I need to explicitly delete the child from the parent…… -
Java – spring boot devtools gets ClassCastException from the cache
I'm having trouble getting value from the cache java.lang.RuntimeException: java.lang.ClassCastException: com.mycom.ad…… -
Suggestions for finding end-to-end Java CPU profilers [closed]
What good end-to-end CPU analyzers exist in Java? Quick list I'm looking for: >Offline analysis – no user interacti…… -
Java – signal / slot mechanism
For people with relatively new Java ecosystems, is there a fairly lightweight way to perform the processing of their s…… -
Java – how to read line by line using FileReader
Thank you for your attention I created a program and I am using the login form and registration form Once users regist…… -
java – EJB3 / JPA @Transactional
Is there an EJB or JPA annotation equivalent to spring's @ transactional? Solution The equivalent EJB 3 attribute is j…… -
Java – how to make jtidy format HTML documents well?
I'm using jtidy v.r938 I'm using this code to try to clean up the page final Tidy tidy = new Tidy(); tidy.setQuiet(fal…… -
Is there a data structure / library in the memory OLAP / pivot table in Java / Scala?
Related issues This question is very relevant, but 2 years old: in memory OLAP engine in Java background I want to cre…… -
Jpa-2.0 – JPA cascading persistence – many to one
I have a one - on - one relationship and I'm trying to stick to a sub - entity public class Office { public int id; pu…… -
Java unchecked / exception clarification
I've been reading about unchecked and checked questions, and no online resource really knows these differences and whe…… -
Java – overrides tostring() using overridden tostring()
Basically, that's what I want to achieve classname @ address(？) [original tostring()], the name of the object and the…… -
Java – where can I find the base64encoder class?
Hi, I saw an example with this code on stackoverflow: String encoding = Base64Encoder.encode ("test1:test1"); HttpPost…… -
Java 8 – zoneddatetime is not equal to another zoneddatetime
I created two zoneddatetime objects, which I think should be the same: public static void main(String[] args) { Zo……