Java
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Java – CPU usage and object wait
I use jpprofiler to analyze my application, so in the "CPU view" section, it shows that more than 40% of CPU time is s…… -
What is the best way to deal with low memory in Java?
We have an application that generates a new JVM and executes code on behalf of our users Sometimes, there is not enoug…… -
Javafx2 – poor performance when dynamically adding custom (fxml) panels to grid boards
problem My attempt I tried to expand from the pane public class Celli extends Pane{ public Celli() throws IOExcept…… -
Java – should the constructor of a private inner class be declared public or private?
Is there any practical difference public class OuterClass { private class InnerClass { public InnerClass()…… -
Java – interruptedexception cancel file open dialog box – 1.6 0_ twenty-six
The output of the following code is: java.vendor Sun Microsystems Inc. java.version 1.6.0_26 java.runtime.versi…… -
Java – width of jcombobox
I've created one jCombo@R_231_2419 @, but it requires the full width of the frame How to set a fixed width For the fra…… -
Java – why return null (Boolean value required) as the result of ternary operator compilation?
See English answers > Booleans, conditional operators and autoboxing I'm not allowed to write public boolean x() { …… -
Java – volatile semantics relative to other fields
Suppose I have the following code private volatile Service service; public void setService(Service service) { this.…… -
Java – a collection behaves like a queue, but allows me to get multiple elements at once?
I'm looking for a data structure that behaves like a queue (it may be a queue implementation), but allows me to get mu…… -
Java – what is the Maven coordinate of the Tomcat JDBC connection pool?
What is the Maven coordinate of Tomcat JDBC connection pool? Solution Through the improved search function on the Mave…… -
Java – where to use callable and runnable interfaces?
I am a novice in Java. I am reading the concept of multithreading. I have experienced these two concepts in various im…… -
Java – how to set the distance between vertically sorted elements?
I have this Code: JPanel myPanel = new JPanel(); myPanel.setLayout(new @R_778_2419@Layout(myPanel,@R_778_2419@Layo…… -
Java – @ cacheable breaks dependency injection
I stumbled upon a case in which the AOP proxy created with @ cacheable was created in spring 3.1 Dependency injection …… -
Java – why must an abstract method be implemented by the first concrete class rather than a further chain?
I'm curious why abstract methods must be overridden by the first concrete implementation class rather than hierarchy c…… -
Return ArrayList from WebService in Java
I have a problem returning ArrayList from Web Service (Java) I have written a test web service and client that consume…… -
Is there an alternative HTTP tunnel using RMI in Java 9?
So I see that the HTTP tunnel through RMI has been deleted in Java 9 We sell commercial Java software running in Tomca…… -
Document – get the global coordinates of the node in JavaFX
How to get the actual location of nodes in the scene Absolute position, regardless of any container / conversion For e…… -
Java – run each JUnit test using a separate classloader (no, really)
How can I have JUnit use a separate classloader for each test class it executes? I'm writing a JUnit testrunner for a …… -
java – ResultSet. getTimestamp(“date”)vs ResultSet. getTimestamp(“date”,Calendar.getInstance(tz))
java. util. Date,java. util. Timetamp seems to have caused great confusion to many people There are so many problems i…… -
Java – executable can be called Jar file instead of using its full path?
I have one Jar file, I want to be able to call it without using the full file path to its location For example, if The…… -
Java – how to publish files using jsoup?
I use jsoup to publish values using the following code: Document document = Jsoup.connect("http://www......com/....PHP…… -
Java – get the inserted ID in the same statement
There is already an answer to this question: > how to get the insert ID in JDBC? six Thanks for your help. John pol…… -
How to delete elements in ArrayList from the indicated index
As shown in the figure, after running one method at a time, I want to delete the old item and prepare for the next cal…… -
Java – case insensitive checking of roles in HttpServletRequest
javax. servlet. http. The HttpServletRequest class has a method named isuserinrole I use it to check whether the user …… -
How to suppress the “picked up java_tool_options: – javaagent: / usr / share / Java / jayatanaag. Jar” message
I use Ubuntu 15.04 and Java 1.7 After updating to 15.04, whenever I enter any Java command, I will receive the followi…… -
Confusing the use of synchronization in Java: patterns or antipatterns?
I'm doing a code review of changes to Java products I don't own I am not a Java expert, but I strongly doubt that this…… -
Java – number of processor cores and size of thread pool
Many times, I've heard that the number of threads maintained in the thread pool is better than the number of cores in …… -
Multithreading – multi core CPUs share MMus and page tables?
On a single - core computer, one thread executes at a time At each context switch, the scheduler checks whether the ne…… -
Java – persistence. 0 was not found during Maven testing xml
I'm trying to load the test database in the test database for the Maven build process of integration testing persisten…… -
Java – JSF CDI: dialog scope bean [S] best practices
I am currently learning JSF 2.0 and am very happy with the existence of this session scope function, which is very use…… -
Algorithm – track the median of the extended array
Interview questions: The following edit gives you an array You make 2 stacks, one minheap and the other maximum heap N…… -
Java – persistent connection with JDBC to MySQL
I have an application that uses JDBC to connect to MySQL In some cases, the JDBC connection is idle for hours (or even……