Java
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Java – RMI server exception
When I try to run a server using a remote registry, I get the following exception from RMI The registry code of my mai…… -
Java – the difference between classes and packages
What is the difference between classes and packages in Java? Solution Class is a declaration (usually an implementatio…… -
java – Integer. Parseint() does not resolve large negative numbers
When I try integer Why is numberformatexception thrown when parseInt ("80000010", 16)? This is a 32 - bit number, whic…… -
Java – Android replaces multiple characters from a string
I know it may be an amateur problem, but for some reason, I don't remember how to do it String s ="["; String q ="]"; …… -
Is the result of mathematical operation on Java – double completely repeatable?
I have a complex data processing algorithm, using java 8 and double as the data type Given the same input (hundreds of…… -
Java — on doubles and equality
I have a method that returns a double When I tested this method as part of JUnit, I noticed the following oddities: St…… -
Java – is an if else tree the best approach in the following situations?
What am I doing: I'm creating a simple calculator in Java that reads a string written in postfix notation (for example…… -
Thread problem in Java HashMap
Something happened that I'm not sure should work Obviously it's because I've seen it, but I need to find the root caus…… -
Java – a naming convention for variables that work like constants
I have a variable that I'm using like a constant (it never changes) I cannot declare it as a constant because the valu…… -
Where can I find Java main functions
Is public static void main (string [] args) a built-in or user-defined or overridden function of some classes provided…… -
Java – how to avoid instanceof calls?
I defined this simple method: public static boolean isBorder(int x,int y) throws CollisionDetectionException { …… -
Java – what is system in
Consider this scanner input example Scanner user_input = new Scanner( system.in ); The scanner is class user_ Input is…… -
Java string Split() deletes trailing empty entries
I'm trying to parse some pipe delimited records I have this Code: public class Test { public static void main(Stri…… -
Inconsistent Java performance
I have an interpreter written in Java I tried to test the performance results of various optimizations in the interpre…… -
Can Java 10 compiled classes run on 9?
See the English answer > can Java 8 code be compiled to run on Java 7 JVM? 5 Is my hypothesis correct? Solution Thi…… -
How to use file. XML in Java Mkdirs () writes elegant code?
I need a directory to save the file, but I'm not sure if it exists File saveDir = new File("/tmp/appname/savedir/"); i…… -
Java – clarification of “int” numbers starting with 0
public class Test { public class Test { public static void main(String[] args) { int i = 012; Sys…… -
Declare the initial value of BigDecimal array in Java
I want to declare a BigDecimal array with an initial value of 0, as follows: BigDecimal[] val = {0,0}; But it doesn't …… -
Java – matrices does not work in OpenGL
I am trying to create an orthogonal matrix and an appropriate model and view matrix to view a simple triangle just to …… -
Try to create a hash table in java with string as the key and double as the value
In the following procedure: import java.util.*; public class HashTableStringdouble { // private Hashtable<String,…… -
Java – Test thymeleaf custom dialect with mockito
I recently wrote a custom dialect and a custom processor for thymeleaf to handle some custom tags and replace them wit…… -
Java – how to establish websocket connection in Android service?
I've been trying to create an Android service that will allow me to maintain a websocket connection and send some data…… -
Unable to create service com parse. PushService：java. lang.NullPointerException
I'm using the service https://www.parse.com Push notification My code: ParseCrashReporting.enable(this); …… -
JBoss logging for Java unit testing?
I inherited some java code explicitly implemented using JBoss logging I know this is usually configured as JBoss subsy…… -
Java – tolower case (char) method?
Obviously, there is a method that accepts a char and returns a char: http://download.oracle.com/javase/6/docs/api/java…… -
Java – Tomcat JDBC connection resource not published
I have a project using Tomcat JDBC connection pool According to JDK specification, connection The close () method shou…… -
How to convert XML to JSON in Java and avoid the parser trying to parse strings into numbers
I'm using org json. XML library to parse XML into JSON http://www.json.org/javadoc/org/json/XML.html In my XML documen…… -
Java – cannot add to ArrayList “misplaced construct (s)”
I have a simple ArrayList setting, but I can't seem to add objects import java.util.ArrayList; public class Inventor…… -
Java – update database in JSP
I wrote this java code for my JSP page to update the user's current login details The code does not show any errors or…… -
Java – use the long string in JSON (> 1 show) of Jackson token stream
I'm trying to write some code to process JSON documents, which contain extremely long string values (more than 1 billi…… -
How about Printing Java maps?
See English answers > How do I effectively iterate over each entry in a Java map? 38 I created the following maps: …… -
Java – error trying to create hive table using custom serde
I have a file that contains the data that needs to be uploaded to the hive table I wrote a custom serde (which is basi……