Java
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Java – why does the LinkedHashMap class implement the map interface?
See English answers > Why do many collection classes in Java extend the abstract class and implement the interface …… -
Java conventions for accessible data (public visitors and recipients / naming)
Through the Java API, you can see countless conflicting naming and practices, which is really confusing to me For exam…… -
Java – how do I format numbers in the expression language?
How do I format and output numbers (such as long or BigDecimal) in El? For example, I want to limit some decimal numbe…… -
How to transfer files between TCP server and TCP client in Java
I have implemented simple TCP server and TCP client classes, which can send messages from the client to the server, an…… -
Java – converts the timestamp length to the normal date format
In my network application, the time of some activities of the user is stored as a timestamp in the database (in the da…… -
Java – Maven: “error reading prototype directory”, not proxy
Command: mvn archetype:generate -DarchetypeArtifactId=maven-archetype-quickstart -DinteractiveMode=false -DgroupId=org…… -
Can bufferedimage be converted into img data URI in Java?
I created a graphic image with the following example code BufferedImage bi = new BufferedImage(50,50,BufferedImage.TYP…… -
Java – the difference between sha256 and RSA and sha256, and then RSA
What is the difference between using the following two methods to calculate a signature? >Use signature GetInstance…… -
Create repeated timer reminders in Java
I want a class that changes its private variables every 2 seconds I know if I do something import java.util.Timer; //.…… -
What is the correct action to take when closing a window in Java / swing?
I wrote this test code in my customuipanel class: public static void main(String[] args) { final JDialog dialog = …… -
How to initialize dynamic arrays in Java?
If I have a class that needs to return a string array of variable dimensions (and the dimension can only be determined…… -
Java – “package should contain content type part [m1.13]”
I tried to write to an excel file, but I kept getting an error: According to my understanding, I missed a jar file Any…… -
Java – thread / handler error – the specified message queue synchronization barrier flag has not been published
I received this error – As a relative newcomer to Java / Android, there is no doubt that I missed something, but what …… -
JavaFX IllegalStateException when processing jfxpanel in swing
I just came across something strange about JavaFX and swing When processing a JavaFX panel that has been added to a JF…… -
Java – how to populate with a list?
I have a list < string > in the controller I pass to the view I need to fill in < form: Select > with thes…… -
Using classpathxmlapplicationcontext in a stand-alone Java class
I haven't touched spring yet I saw the following code in a separate java project in my system You can help me understa…… -
Spring – JPA and Dao – what is the standard approach?
I am developing my first application using JPA / Hibernate and spring My first attempt in Dao class looked like this: …… -
Java – why do anonymous classes access non final class members of closed classes
We know that the final local variables can only be accessed in anonymous classes. Here is a good reason: Why are only …… -
JUnit – select the specific test run in gradle
I'm trying to solve our chaotic test run. Unfortunately, I've just graduated We currently have TestNG and JUnit, and I…… -
Using java zip files: are there any restrictions?
I am creating backup routines for Java applications I'm also testing Apache commons compression to tar GZ, but its fil…… -
Java – Maven: compile and test at different source levels
I am currently developing a project to run on embedded devices The device runs Java ME JRE (equivalent to Java 1.4) Be…… -
Java – restore the old style of NetBeans 7.2 bookmark navigation in any way?
NetBeans 7.2 changed the way bookmarks work Before Ctrl Shift and Ctrl Shift Move the focus up and down in the same fi…… -
Java – after the authentication needs window pops up 7u21 and is updated
I've been working on a project for the past six months For this project, I have a GlassFish server instance in which w…… -
Java – how to pass a variable number of parameters to ant Exec
I have an ant target that accepts some variable parameters that can be passed to the exec task Using the old mechanism…… -
Java – fail fast iterator implementation
There are similar questions, but not exactly what I want to ask This link says that its implementation exists in the a…… -
Java – the data source JMX MBean cannot be unregistered when the spring boot application is closed
I have a simple spring boot application using org apache. commons. dbcp2. Basicdatasource as a datasource bean The dat…… -
Java – how to use the string list in namedparameterjdbc template to get the result
Try spring JDBC I use this as a reference I'm trying to get an actor with the same name Running this code gives me the…… -
Java – align swing components across panels
We have a JPanel that contains multiple jpanels containing jcomponents (let's say jlabels and jlabels) JText@R_540_241…… -
Java – remove the “Z” section from xmlregistry calender
When I like it below, GregorianCalendar calendar = new GregorianCalendar(TimeZone.getTimeZone("UTC")); calendar.setTim…… -
Java – change the default XML namespace prefix generated using jaxws
I am using jaxws to generate a web service client for the Java application we build When jaxws builds its XML for use …… -
Avoid multiple if statements in Java
I have written such a method But I think it should be refactored private String getMimeType(String fileName){ if(fil…… -
java – SimpleDateFormat String
I have this code block, where dateformat The format parameter will always be a string, which is why I do this ToString……