Java
-
Java – why is there no exception in this byte?
I initialized a byte as follows: byte b = (byte) 0b11110000000; Since a byte is 8 bits in size, I expect it to throw s…… -
Lambda – the Java 8 stream is composed of three fields and aggregated by sum and count to produce single line output
I know that similar problems have been raised in the forum, but none of them seem to have completely solved my problem…… -
Java – array initializers are not allowed here
I have some model classes. I try to declare a list with them, but I get that the array initializer is not allowed here…… -
Java – cut and stack arrays
I have an int array as input The length of the array is always 2 ^ n. I want to cut the array in half and stack it Rep…… -
Java cucumber: obtain @ cucumber options from external sources, such as property files
Whether it can be from Java Get the cucumber option value from the properties file? In this so post, it shows that it …… -
Java – Convert list to map and filter null keys
Using the Java 8 stream, I want to convert the list into a map as described in the solution of Java 8 list < V >…… -
Java — call Runtime. in the onLowMemory method. gc()
Should we use runtime GC () or system GC () to clear the memory in the production code in the onlowmemory () method in…… -
Java Runtime. getRuntime(). Freememory() problem
I searched and saw some threads, but none solved the specific problem I encountered I tried to use runtime getRuntime(…… -
Using java to convert children to parent problems
class Parent { class Parent { int i = 60; } class Child extends Parent { int i = 70; } class Main { pub…… -
Java – how do I use group mapping streams?
I have a long child // ordered by parent.id / child.id Stream<Child> childStream; Say, Child(id = 1,parent(id = …… -
Java – how do I check that the value is equal to at least one field in the list?
I have this method: for (String fieldName : fieldArray) { Query query = new Query(); query.addCriteria…… -
Java – 25 even and even random number generator
I need to generate 25 random numbers and divide them into two arrays, depending on whether they are odd or even This i…… -
How do I scroll down to click an element in Android using appium and Java?
I wonder how to scroll down to click an element in Android using appium and Java? I have a list of elements in "Androi…… -
Java – why does my scanner still need a blank char
Input: 1 2 3 Objective: each number will be filled in the same array Space will be excluded Scanner in = new Scanner(s…… -
Java – JUnit: call @ after to set the object to null
Suppose I have the following simple JUnit test private Person person; @Before public void createObject() { String …… -
Java – if the return type of the rewriting method is original (such as double), can we change the return type of the rewriting method (such as int, char)?
As follows: Method to override: double add (int a,int b){ } Method of covering the above method: int add(int a,int …… -
Java-8 – pass the Java 8 stream mapping function as a parameter
I have a comma separated string that I want to convert to an array But in some cases, I need integer parsing, and some…… -
Java – how to visualize recursion
I try to understand recursion in Java through visualization I've taken some tutorials on youtube and used one of the e…… -
Repeated projection of Java nested mapping
Why does the actor work? import java.util.HashMap; import java.util.Map; public class TestMap { public static voi…… -
Java 8 lambda specifies the map type and makes it immutable
I have the following code, generated using Lambdas for several months Map<Integer,String> tempMap = new LinkedHa…… -
Java 8 stream – merge two sets to make them unique in a specific field [copy]
See English answers > java 8 distinct by property 20 This is the best I can do in Java, but it collects unique name…… -
Java – how do I wait for the alert box to perform an action in selenium?
I press the Cancel button than check some text according to my code In chrome and Firefox, it works normally, but in i…… -
Java – should hibernate use a unique sequence for each table?
I have several entities using automatic key generation strategies with hibernate and Postgres @Id @GeneratedValue(stra…… -
Pass checkstyle to Java Hello World
So I'm a novice using checkstyle. For my simple HelloWorld Java program, I received a lot of errors that I don't under…… -
Convert an existing c# synchronous method to asynchronous using async / await?
Starting with the synchronous I / O binding method (shown below), how do I use async / await to make it asynchronous? …… -
java – android. support. v7. app. ActionBarImplICS. Getthemedcontext NullPointerException in Android
Please help me get Java lang.NullPointerException java.lang.NullPointerException at android.support.v7.app.ActionBarIm…… -
Java – eclipse / ant creates a jar in version 1.9, even if everything seems to be set to 1.8
I have a project built using ant and eclipse, and I want it to be compatible with Java 8 When I try to run jar using j…… -
Java – where does Maven search for log4j Properties file?
I am using log4j with Maven to face problems I have a properties file, log4j Properties, I put this file in the POM. N…… -
Java 8: default method for automatically synthesizing multiple interfaces
I have classes that implement multiple interfaces with the same default methods I want to know how to synthesize defau…… -
Java – spring: you cannot connect to JMX server from behind the firewall using RMI
My spring application runs on the machine behind the NAT firewall (pfsense) The internal IP of the machine is a.b.c.d …… -
Java – @ datetimeformat not recognized
I tried to annotate a localdatetime object with @ datetimeformat My main idea is that once a string is received in the…… -
Match two very large vectors with tolerance (fast! But workspace reserved)
Consider that I have two vectors One is the reference vector / list, which includes all values of interest and a sampl……