包含标签：Java 的文章
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Java – why link string Will trim () throw an exception?
Sorry, if this is a stupid question, but I can't find an explanation I have a string like this: String str ="This is 5…… -
JavaFX – how to add a container in the anchor pane
I have a simple project that contains fxml. XML with a splitter So fxml is like this: <AnchorPane id="AnchorPane" p…… -
Java – how many elements does ArrayList add when it resizes itself?
Java's ArrayList dynamically extends itself when needed How many elements will it add when the extension occurs? Does …… -
Java – breaks a string into two at a hyphen
I get the string variable from the request String issueField = request.getParameter("issueno"); This may or may not ha…… -
java – Codingbat- Recursion1- count7
Anyone can program the next question for me (from codingbat – recursion1 – count7) Given a nonnegative int n, the numb…… -
Java – under what circumstances thread Is sleep () the best way to pause a thread?
Thread. Sleep () seems like a very useless concept to me, because the only way I see it work is in the following scena…… -
Override the list result type in Java
I want to compile some variations of this code in Java class X { List<X> getvalue(){...}; } class Y extends…… -
Java – get the class name with generic information
In the Java serialization problem, I want to save some class names. I have some problems with generic classes Any idea…… -
Get metadata information of file owner using java
I am trying to retrieve the owner of the file using the following code: Path file = Paths.get( fileToExtract.getAbsolu…… -
Java – override generic methods using non generic implementations
I was trying generics in Java and thought of this example If I have classA < T >, I can override it with Subclas…… -
Java – VTD – XML parsing performance (key factor of speed) Request feedback / comments
I'm about to use VTD XML (in http://vtd-xml.sourceforge.net/ Found), but I'm interested in getting feedback on any act…… -
Java – how to create CSV files using servlets?
I want to download the CSV file from the servlet Data from object [] obj = search getSearch(); I have a data object []…… -
Java – when we change to bytes, why is the result – 2 when 127 * 2?
This is my code: public class test { public static void main(String[] args) { byte a=(byte)127,b=2; byt…… -
Java – rest Service on wildfly pathparam is empty
I am building a rest service using Jee 7 and deploying it on wildfly 8 With the exception of pathparam, everything see…… -
Algorithm – search for the 7th largest element in the largest heap?
So my friend and I don't agree on this issue It requires the time complexity of searching the 7th largest element in t…… -
Java monthly timer
I'm trying to create a timer / TimerTask that will run on the same day of each month I can't schedule a repeat timer b…… -
Java Concurrent HashMap
I want to convert concurrenthashmap to treemap Can I do that? Solution If you need a sorted concurrentmap, please chec…… -
Accessing subclass fields from a base class in Java
I have a base class called geometry, in which there is a subclass sphere: public class Geometry { String shape_name;…… -
Java – refresh the Android viewpager fragment on refresh
I'm new to Android. I really don't understand why the dynamically added fragment content (such as some images added af…… -
How to truncate PostgreSQL tables from JDBC
I have a PostgreSQL database. I want to truncate some tables using JDBC What do I do? This is what I've tried, but the…… -
Detect pending Linux shutdown
Since I install pending updates for my Ubuntu server as soon as possible, I have to restart my Linux server frequently…… -
Java [unchecked] unchecked case warning
Well, I've been looking around and doing a lot of Google searches, but I still can't find a way to avoid this warning …… -
How to use mockito to simulate a for loop
I'm new to mockito My question is how to use mockito to simulate a for loop? For eg: This is the main class: import ja…… -
Java – intentional Android contact information update?
I can use putextra to transfer information as additional data to create a new contact with intent. Can I use informati…… -
How to implement (x POW y) in Java, where x and y are double?
I want to calculate the power of X, y, x, y are double values Why did Java give me a compilation error? What is the be…… -
Get the location from the execution location of the Java code
I have a swing Java application that can save a lot of data (for example, you can consider games and their saving) The…… -
Does Java’s split overwrite the length of the array, even if it is pre initialized?
String [] arr = {" "," "," "}; // String arr = new String[4]; String [] arr = {" "," "," "}; // String arr = new Str…… -
Java: Refactoring static constants
We are refactoring some code We developed a feature in one project and we want to use it in other projects We are extr…… -
Java – calling the run method directly is not a good practice
In most cases, I want to run a piece of code in a new thread, which will take some time, but in some cases, I want to …… -
ORM – primary key – native, sequence or GUID key?
When I read this and this, and then read this (which ironically quotes the other two), I found that I wanted to know h…… -
Where is the Union () method of the Java – spark dataframe class?
I am using Spark's Java connector and want to combine two dataframes, but the strange thing is that the dataframe clas…… -
Java – method. Java is called when a parameter in an array invoke()
I have the following interfaces: interface Foo { void bar(String a,int b); } I want to call foo reflexively Bar (on ……