Recent Posts
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Java – warn: failed to register destroy callback
This warning message appears a lot in my log For each managed bean, as long as it expires After the given time, becaus…… -
Maintain the map (Collection) of inserted orders in Java
I need to use maps for Android Application in Java But the problem is that the list is sorted automatically How to use…… -
Java – can jmenubar be added to the decoration window of JFrame?
I want to know if I can add jmenubar to the decoration window of JFrame or jrootpane, or if I can include the border i…… -
Java – Atomic increment of long variables?
If the long variable is declared as: – Long counter = 0; Now, if I use the pre increment operator to increment it, is …… -
Java – polymorphism of member variables I know it’s impossible. I don’t understand the specific situation
I know this behavior, but I'm not 100% sure why it happened class Animal{ String name = "Animal"; public voi…… -
Java – Hibernate: delete many to many associations
I have two tables associated with many to many – DB segment: Load ID name Meeting Id date sessionsloads LoadId SESSION…… -
Does the java compiler optimize repeated mathematical calculations?
The java compiler optimizes simple repetitive mathematical operations, such as: if (prevX / width != curX / width) { …… -
java – org. junit. Assert. Assert is better than org hamcrest. MatcherAssert. assertThat？
I am new to JUnit and hamcrest and want best practice advice, so I can decide which documents to study first For begin…… -
Java – getters / setters of classes with maps
What are the best practices for implementing / providing getters / setters for courses with maps? The most common impl…… -
Java – write a method to replace all spaces in a string
I have a question about programming, starting with gayl laakmann McDowell's "cracking the code interview" in the fifth…… -
Java URL protocol: classpath: /?
I see some spring code that uses the classpath: / some / path / to / resource URL protocol to read configuration files…… -
Vector creation and VEC! Macros contain different capacities
I have a vectormatrix_ a. It contains three vectors and is initialized with VEC! Macro Because VEC:: with_ Capacity (D…… -
Java – what is “VM recurring task thread”?
I can see this thread in my thread dump: "VM Periodic Task Thread" prio=10 tid=0x00007fc23000e800 nid=0x49e6 waiting o…… -
Java – mockito – a method that stores the object returned by the mock object method
Suppose I have a mock object. I don't want to stub any of its methods, but I want to store a method of the returned ob…… -
Java – is the root cause of log4jlogger missing or unavailable?
I have commons - logging in the classpath Jar (v1.0.4) and log4j-1.2 8. Jar and get the following runtime error: Cause…… -
Java – convert a for loop to a concat string of a lambda expression
I have the following for loop to traverse a string list and store the first character of each word in StringBuilder I …… -
Java – partial JSON serialization at runtime (for restful queries)
I'm trying to convert Java objects in Tomcat to JSON (currently using Jackson) Based on the fields in the restful requ…… -
Java – used to define the disadvantages of non static recorders
How do you reduce Java logging boilerplate code? It is strongly recommended not to use recorders as instance member va…… -
Logical solution algorithm (applicable to Sudoku in Java)
I have a problem with my logic algorithm It solves the problem of a large number of hints, which is only a problem wit…… -
Java – how to extract values from JSON
I get a response string from the server, as shown below {"name":"Json","detail":{"first_name":"Json","last_name":"Scot…… -
Mp3 coding in Java
I need an opensource API in Java that can convert * WAV and * Au format is encoded as MP3 and vice versa I have evalua…… -
Extend a Java ArrayList
I want to extend ArrayList to add several methods for a specific class, and its examples will be saved by the extended…… -
Java – name a loop
While browsing through questions and answers on this forum, I found that a piece of code was given loops to use them f…… -
Java – sometimes it takes 45 seconds to close RandomAccessFile
In my program, close Java util. RandomAccessFile sometimes takes 45 seconds (almost exactly between 44.998 and 45.003 …… -
java – Optional. Ofnullable and method links
I'm interested in optional The ofnullable method surprised me One day I wrote a function that should return an optiona…… -
Java: why is there no warning when referencing a field before defining it?
Static fields cannot be referenced until defined or initialized: static Integer j = i; /* compile error */ static fina…… -
What is the smallest Java Web MVC framework?
I am looking for a java web framework that requires minimal configuration for a very small application Struts is defin…… -
Extend a Java ArrayList
I want to extend ArrayList to add several methods for a specific class, and its examples will be saved by the extended…… -
Will an assertion error be found in the catch block of the Java exception?
Code:- try { Assert.assertEquals("1","2"); } catch (Exception e) { System.out.println("I am in error block"); …… -
Java generates and parses instance code for XML format files and strings
1. Basics: there are generally four methods for parsing XML in Java: DOM, sax, JDOM and Dom4j. 2. Introduction to DOM …… -
Java uses JDBC to operate database example sharing
package dao; import java. sql.*; public class BaseDao { //oracle // private static final String Dirver="oracle.jdbc.dr…… -
Implementation of Java design pattern object pool pattern example sharing
Objectpool Abstract parent class