Java
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How to store Java types and allow only some specific types?
Suppose I want to have a class descriptor for records, where each record has a set of properties Each attribute has a …… -
Undiluted date, with additional numbers in Java
What's wrong with this code? I try to parse the date format between months and months import java.text.SimpleDateForma…… -
Severe: Java class not found util. Message body writer for ArrayList and mime media types application / JSON
I'm testing the restful service. When I execute, I get an exception. Although there are the following jars in my class…… -
Java – generics and CompareTo () methods
I'm trying to create a skiplist. I have a method using common data types: public void add(E key,Integer value) { N…… -
Java – why does jmh run different forks?
I use the jmh benchmark framework（ http://openjdk.java.net/projects/code-tools/jmh/ ）Run the benchmark on my code My…… -
Java – how to use POI to set the author name as an excel file
I am using poi (Java) to create an excel (. Xlsx) file After I created the excel file, I saw the excel file as "Apache…… -
Java executorservice pauses / resumes a specific thread
Is there any way to use executorservice to pause / resume a specific thread? private static ExecutorService threadpool…… -
Java – why are we in JSP instead of system out. Write out in println() println()？
I started learning JSP. I saw that if we want to print something in JSP, we must write out Println () instead of syste…… -
Java – recursive BeanUtils describe()
Is there a version of BeanUtils Describe (customer) recursively calls the describe () method to the complex attribute …… -
Java – how to get the line number of a method?
Can I get the line number of using reflection or other magic methods? Solution I want to do the same thing. After some…… -
Java – logger slf4j does not have the level configured with logback
My log record is through logback Configuration of logback using groovy files Now, when my Maven POM project aggregates…… -
Java – what should developers know before developing mobile applications?
I want to start making Android mobile apps as my first choice, but not the only one I have 10 years of experience in J…… -
Java: programmatically determine the names of all packages loaded on the classpath
Any suggestions on how to handle how to find the list of package names that exist in the current classpath? This needs…… -
Java – logger slf4j does not have the level configured with logback
My log record is through logback Configuration of logback using groovy files Now, when my Maven POM project aggregates…… -
java – Objects. Requirenonnull (t obj) instead of null check and throw illegalargumentexception manually?
Whenever I check whether the given parameter of a method is not null, if the null check fails, I use it to write a nul…… -
Java robot keyboard command key
VK of command key on MAC_ [key] what is the code? I tried to get a Java robot to press the command key I'm using the c…… -
Java – Maven plugin build failed when using Lambdas
I wrote a maven plugin / mojo to generate some code The plug-in runs well and has built-in Java JDK 1.8 I see some str…… -
Java generics and wildcards are compiled in eclipse, but not in javac
As a follow-up Java genetics compile in eclipse, but not in javac, I released another code segment compiled and runnin…… -
Java – smack client – the user is still online even though the connection is aborted
I use smack to build a small XMPP client / BOT to experience a very strange behavior I set up a connection and a conne…… -
Multiply by two vectors – I want a scalar, but I get a vector?
This is my code: a <-c(1,2,3) b <-t(a) print(a*b) I expect the result to be 14, because the multiplication of th…… -
Java – returns a string from JMS
I'm writing an independent main method that calls a producer (pushing data into a queue) and then calls a consumer who…… -
Array – the goal of combining LinkedList with string reverse is to understand LinkedList
I tried to use a link list program to display the reverse string entered by the user Here is my program to reverse the…… -
Java – use Apache POI to read the contents of the drop-down list from excel
I need to create a drop-down list (data validation) on a specific cell in the excel worksheet and read it back With th…… -
ORM – non destructively delete entities in symfony2
Is there a good, clean and simple way to delete entities non destructively in symfony 2? I want the administrator to h…… -
How to monitor available memory (including cache and cache) in Java?
I have searched for possible solutions, such as how to monitor the computer's CPU, memory, and disk usage in Java But …… -
Java – how do I associate a string with each member of an enumeration?
Suppose I have some enumerations as follows: enum Towns { Rome,Napoli,Modena } I want to associate a string with each …… -
Java – can I double or BigDecimal overflow?
Java 8 gave us math Addexact() is an integer, but not a decimal Can double and BigDecimal overflow? According to doubl…… -
Java process memory grows infinitely Memory leak?
We have a java process running on Solaris 10, serving about 200-300 concurrent users Administrators have reported that…… -
Java – publish AAR files to Maven central, gradle does not work
Publishing a file to Maven central and gradle still doesn't work: OK, let's restate all the steps I follow and try to …… -
. Net – naudio tone conversion
I'm using the naudio DLL. I'm looking for sample code for tone conversion sound Solution In the open source Skype Voic…… -
Java – generate warnings for auto boxing usage
I want to generate warnings for all auto boxing and unboxing Has anyone found an effective way? Eclipse captures basic…… -
Java – unable to generate classes from JAXB in Maven environment
I used the xjc plug-in in the Maven environment and tried to generate classes from schema [ERROR] null[5,30] org.xml.s……