Recent Posts
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Java – restlet client repeatedly calls restlet server suspend
I am using restlet to implement web services The client (also using restlet) makes several consecutive calls to the se…… -
Java implicit conversion
Use the following code: Float a = 1.2; There is an error because it takes decimal as the value of double, which is a l…… -
Java: text strings
class A { class A { String s4 = "abc"; static public void main(String[]args ) { String s1 = "abc"; …… -
Java – why is static final slower than new at each iteration
Why is code snippet 14 times slower than code snippet B? Code snippet A: import java.awt.geom.RoundRectangle2D; publi…… -
How to use JfreeChart to display dates on the X axis of a line chart
I tried to display the line chart with time (HH: mm: SS) as X axis and number (as y axis) for (Row row : sheet) { …… -
“No select item” on JavaFX combo box?
stay Combo@R_705_2419 @What is the correct way to place items with null values in? Exception in thread "JavaFX Applica…… -
java. sql. Sqlexception: no suitable driver found
I tried to use the following dbquery The Java class performs a simple query, which uses the dbconnector to obtain a co…… -
Java – displays JPA SQL statements when using play framework 2
I am developing a web application using play framework and JPA / hibernate For debugging purposes, I'm glad to see the…… -
Java – how to read the heap dump file created by jconsole?
I call com. through jconsole. sun. management. Dumpheap operation of hotspotdiagnostic mxbean to manually perform heap…… -
Displaying opencv mat using JavaFX
I want to display the mat object in opencv directly with JavaFX I've seen that the mat object can be converted to buff…… -
Java does not have information about all IANA time zones
I'm trying to map the value from the front end to the zoneid class, as follows: Optional.ofNullable(timeZone).map(Zone…… -
Jbpm6 service task execution java code
I'm new to jbpm6 My scenario is like this. I want to use jBPM service task to execute some java code From the document…… -
How to capture Ctrl mousewheel events using inputmap
I have implemented some hotkeys for swing applications that use inputmap getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW…… -
Java – should the mandatory utility class be final and private constructors?
By creating private constructors, we can avoid instantiating classes from anywhere outside By making the class final, …… -
java – joda. time. Datetime deserialization error
I tried to deserialize a class with datetime as attibute: import org.joda.time.DateTime; import com.fasterxml.jackson.…… -
Unit testing – use arquillian and powermock in the same JUnit test
I want to use the functions of arquillian and powermock in the same JUnit 4 test The problem is that both products are…… -
Java – how to call onCreateOptionsMenu from code
I want to call onCreateOptionsMenu from my code, because if I use: menu.setGroupEnabled(0,false); Attached: public Men…… -
Java – how does the behavior differ between these two synchronous usages in the list?
List<String> list = new ArrayList<String>(); List<String> list = new ArrayList<String>(); list…… -
Java – errors in eclipse are unprovoked
I'm building an Android application I was working on my application today and suddenly I saw all the items in the work…… -
Java Preparedstatement and on duplicate key update: how do I know if a row has been inserted or updated?
With the following code, how do I know whether the execute () method causes insertion or update?: Connection c = Drive…… -
Java comparator: violation of general contracting
So I have this comparator: import java.util.Comparator; public class SolutionComparator implements Comparator<Expr…… -
Java – in eclipse, can you find all methods that take a certain parameter type in the project?
So this is basically my problem I convert all methods ArrayLists to hashmaps in the parameterized method, but I don't …… -
JUnit – missing branch when using asserttrue instead of assertNull
In Java / JUnit, I need to test null with some objects There are many ways to test a condition, but I've been using as…… -
Java – why use volatile members to generate JPA2 metamodels?
I just used org apache. openjpa. persistence. Meta. Annotation processor 6 generates a Metamodel for my JPA2 entity @j…… -
Java – spring @ Autowired field – which access modifier, private or package private?
Suppose we use @ Autowired annotation on each field in the class, and we can set the setter or constructor of the fiel…… -
Java – add elements to 2D ArrayList
I know that for arrays, you can add an element to a two-dimensional array as follows: array[0][1] = 17; //just an exam…… -
How to use the world wind Java SDK offline
I'm trying to use world wind. It's very good and easy to edit But in my case, the application needs to run offline So …… -
Java – add / modify suggestoracle after building suggestbox in GWT
I can do it for you Suggest@R_804_2419 @All the information found by and multiwordsuggest Oracle shows that the only w…… -
Generics – lambda and anonymous classes
I have the following code: eventBus.subscribe(new EventBusListener<NavigationEvent>() { @Override public…… -
java – StringBuilder vs. . Concat vs. “is the relative performance of operators in eclipse different from the command line?
I'm reading about how, where possible, the java compiler will compile strings connected with the '' operator to an ins…… -
Java – sqlexception: Protocol conflict in Oracle
I received a "breach of agreement" Oracle version used: jdbc driver used by Oracle 11g R2 (11.2.0.3.0): 12.1 Java used…… -
Java code implementation of library management system
This example shares the specific code of Java library management system for your reference. The specific contents are ……