Java
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Java – copy excel tables using Apache poi
How do I use Java Se and Apache POI to copy an entire excel table into another excel table in the same workbook? Solut…… -
Java – why do I get a non convertible type error?
If I use this class: public class BooleanTest { public static void main(String args[]) { final Object[] ob…… -
Java static members in subclasses accessed through generic parent classes
This seems like a new problem, but the last time I use Java, the language has no generics I have a class hierarchy (ch…… -
Java – how to draw images to JPanel or JFrame?
I have read the Oracle tutorial on how to draw images to JPanel or JFrame, but I can't seem to do it correctly I need …… -
Java – is there any reason why some methods in file use Boolean values to indicate its success (not just throwing exceptions)?
The file class in java contains methods that use Boolean values to indicate the success of the operation being perform…… -
Java – JSON and Moshi formatting
Does anyone know how to make Moshi generate multiline JSON with indentation (for human use in the context of config. J…… -
Multithreading – why is Google Chrome renderer multiprocessing rather than multithreading?
Every time I load browser tags in chrome on my Mac, the application forks out to another process This seems to work di…… -
Java – problem downloading file using content disposition
I want my program to have a pop-up window to save as a window option before the file starts downloading, but when I ru…… -
Java – an elegant way to use flatmap in flatingby
So I have a piece of code. I'm iterating over a data list Each is a reportdata, which contains a case with long caseid…… -
Cost per class in a Java application – fewer large classes or several smaller classes
What is the memory cost for each new class added to a Java application? >Is it better to have 5000 large lines or s…… -
How to use Xdebug and eclipse IDE for PHP
Hello, my PHP project is set up on the remote test machine I need to use the eclipse IDE for debugging How can I impro…… -
Java HashMap detected a collision
Is there a way to detect collisions in Java hash maps? Anyone can point out that there are many collisions where some …… -
Java – volatility of reference types – does it always avoid publishing references due to JMM?
Suppose this lesson: public class AmIThreadSafe { private int a; private int b; AmIThreadSafe(int a,int …… -
How to add JDBC Properties to spring / Hibernate?
I encountered the following error when trying to pass the value from the properties file to spring, so I don't have to…… -
Occurs before the relationship in the JAVA memory model
With regard to JLS ch17 threads and locks, it says "if an action occurs before another action, the first action is vis…… -
Java – continue statement marked in the while loop
The following simple example causes compile - time errors But it is not clear why public static void main (String[] ar…… -
The Java synchronization thread did not work as expected
The following code does not work properly: import java.util.ArrayList; import java.util.List; import java.util.Random;…… -
Java shutdown function not executed
In main () of my application, I have the following code to back up the data so that it will not be lost when the syste…… -
Confirm the Java LinkedList “foreach” loop
nice day, Someone can confirm the content at the bottom of the Java – iterating a linked list post. The post mentioned…… -
Java – there is no bean named ‘sessionfactory’ defined after opensessioninview filter
Well, because lazyinitializationexception, I need it on my web Add "opensessionviewinfilter" in XML and use the follow…… -
Java – why doesn’t implicit conversion happen here?
I'm looking to convert a char array to a set of characters Logically, if I write something like how to convert an arra…… -
Java – throw multiple exceptions from a method
How to throw multiple exceptions from one method at a time? Example: public void doA() throws Exception1,Exception2{ …… -
Java – immutable classes and subclasses
I'm trying to learn variable / immutable classes. I met this post Some of the answers provided are: @ h_ 419_ 3@ OK, I…… -
Java – asynchronous HTTP client (ning) create more threads?
I am using Ning async HTTP client to realize the advantages of non blocking Doing an apple to Apple test (non blocking…… -
Java – inherited protected member behavior
I have some questions about the protection identifier In the first chapter of K. Sierra's sun certified java programme…… -
Java – you cannot deploy a simple spring boot web application to openshift
I have one War file. When I copy it to the webapps folder in my local instance of Tomcat 9, it will be successfully de…… -
Java – pass variables from servlet to JSP
I have seen other problems similar to this problem, but none of them helped me solve my problem Basically, I'm trying …… -
Java swing JFrame size returns a larger screen size
When investigating some problems in my application, I found something strange Basically, the sscce should prove this p…… -
Java – spring managed transaction, eclipse link JPA, custom isolation level
I doubt it's embarrassing. I made a mistake in a terrible way, but please wait for me patiently I have a spring applic…… -
Java – JSF 2.1.0 not found 13 custom component: tag library supports namespace: but no tag is defined for Name:
problem I am using JSF 2.1 Create a prototype to demonstrate the benefits of JSF to the webapp we currently build usin…… -
Java 8 maps the collection. If the collection is empty, add the default value
I have a use case, and I must return a set containing at least 1 element The incoming collection may contain 0 or more…… -
Java – pdfbox coded symbol currency euro
I use Apache PDF@R_745_2419 @The library creates a PDF document My problem is to encode the euro currency symbol when ……