Java
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How do I store and reuse key pairs in Java?
I want to generate the key pair once and reuse it public static KeyPair generateKeyPair() throws Exception { K…… -
Java – spring boot jsr-303 / 349 configuration
In my spring boot 1.5 In the application, I am trying to configure support for JSR - 303 / JSR - 349 authentication I …… -
Java – in Hadoop map reduce, will any class see the entire key list after sorting and before partitioning?
I'm using Hadoop to analyze very uneven data distribution Some keys have thousands of values, but most have only one F…… -
Does Java – akka’s event bus guarantee message order?
I want to keep the sequence of events entering the bus The problem is that if this order is guaranteed, whether on clu…… -
Java generic return type is not used in parameter
In the Java library, I encountered a method that uses a generic return type, which is not used in any way in the param…… -
java – Deflater. Deflate and small output buffers
I saw a strange situation, using java 8u45's small output buffer and Java util. Deflater. When the deflate (byte [] B,…… -
Java – how to use the expectedexception rule to test multiple exceptions in a test?
There are questions about the usage of JUnit's expectedexception rule: As suggested here, the JUnit expectedexception …… -
Is there any library that provides a smooth way to build Java format strings?
The syntax of Java format strings may become complex, for example: "|%1$-10s|%2$-10s|%3$-20s|\n" Someone has created a…… -
Multithreading – the QApplication thread is frozen due to another qthread
In my QT application, I created a qthread, which should perform some heavy computing tasks regularly The main Q applic…… -
Java – deserialization with @ jsonsubtypes without value – missing attribute error
I deserialize jsons like this: { "type":"a","payload" : {...} } The type of payload depends on the type My class: pu…… -
Using selenium 2.0 webdriver in practice
I want to write selenium test cases in JUnit and test my project in multiple browsers. I want to take advantage of the…… -
Use the new standard javax JSON serializes POJOs into JSON
I like the idea of using JSON serialization standard in Java, javax JSON is a big step forward. You can create an obje…… -
How to understand the wait and notify methods in java thread?
I am very confused about these two descriptions: >"Wait method blocks the calling thread and relinquishes the monit…… -
Java: preparing statements without connections
I'm trying to generate some SQL files in my java application I want to use Java sql. Preparedstatement creates my stat…… -
Java: how to store references to all instances of a class?
I'm used to C. to get a list of all instances of a class (this is a library class that can be extended by users), I us…… -
Java – does AspectJ not capture all events in the spring framework?
My project is based on spring framework 2.5 4. I try to add aspects to some controllers (I use AspectJ 1.5.3) I'm at a…… -
Java – how to use a custom runner when using categories in JUnit?
I have a bunch of JUnit tests that extend my basic test class basetest, which in turn extends assert Some of my tests …… -
Java – spring utilities cannot be resolved
I'm trying to use one of the Oracle GUI examples of spring utilities But eclipse gave me errors and could not resolve …… -
Build a process pipeline using processbuilder in Java 7
I've been trying to figure out how to manage some processes in Java using the new process builder I can't find a suita…… -
Multithreading – how to limit to asynchronous SEQ in f# Number of threads created by map operation?
The current setting is like this array |> Seq.map (fun item -> async { return f item}) |> Async.Parallel |>…… -
Java NiO zip filesystem is equivalent to Java util. zip. Setmethod() in zipentry
I have some existing code to create a zip file in ePub 2 format, which works properly When trying to update my code to…… -
java – System. Is the value returned by currenttimemillis() affected by the day light savings and leap second adjustments?
I know system Currenttimemillis () gives the millisecond time since the era, and it is very sensitive to the system wa…… -
Java – what is the best way to test this? Binary number with 4 positions
Consider the four input fields a, B, C and D on the web surface. Users can fill in any of these There are 16 combinati…… -
Java – how to make two classes share the same variable definition
What I really need is to be able to declare regular variables in the interface and implement the interface in two clas…… -
Java – direct field access in spring MVC 3
I want to use direct field access for "command objects" in spring MVC 3 Solution You can use the @ initbinder annotati…… -
Java: disk based fast hash set
I need to store a large hash set that can contain up to 200 million 40 bit values It is acceptable to store it as a va…… -
Java – clean up projects and regenerate class files in eclipse
After I cleaned up a project in eclipse, I didn't see the class file generated in the output folder "bin". Although th…… -
Java – how to include all modules in a POM project
I'm looking for a way from another POM XML contains all the modules in the project So in my case, I have a parent POM …… -
Java – read the newline character in CSV, which is referenced in the file in flatfileitemreader of spring batch
I tried to parse CSV files with flatfileitemreader This CSV contains some referenced line breaks, as shown below email…… -
Get split value after Java string splitting
I have a dynamically generated string I need to split the string according to the relational operator To do this, I ca…… -
Java – XHTML to PDF how to cache CSS using fly saucer
In my production pipeline, I need to generate hundreds of PDFs from HTML In this case, I first convert HTML to XHTML D…… -
Java – unable to understand class objects
The Oracle Java documentation on internal locks and synchronization says: I don't fully understand the concept of clas……