Java
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Java – why does getcanonicalpath throw a checked exception while getabsolutepath does not?
I read some relevant texts to understand the difference between the two But I wonder why getcanonicalpath () throws a …… -
Java – inject mock @ service for spring unit test
I'm testing a class that uses @ Autowired injection service: public class RuleIdValidator implements ConstraintValidat…… -
Java – get a file from a remote mercurial repository
Is there a way to programmatically download a single file from a Java Remote mercurial repository? I asked a very simi…… -
Java – converts MIDI counts to names and octaves
Does anyone know anything in the Java world that maps MIDI note numbers to specific note names and octaves For example…… -
Java – multi level static nested classes produce incorrect output
When you run the following code, "x.q" instead of "a" will be printed as required by the language specification Soluti…… -
Do you need a defensive copy of Java enumeration types?
People should return so - called "defensive copies" of private reference types This is to avoid returning references t…… -
Java – play 2.5 3: Use dependency injection to get configuration values
I tried to migrate a play framework application from 2.4 to 2.5 3, and I have questions from application Conf file get…… -
Java – how to serialize classes?
When I insert the list into mongodb, there is a problem: Exception in thread "main" java.lang.IllegalArgumentException…… -
Commercial Java analyzers have an advantage over free ones The one in NetBeans?
Occasionally, I have to do some analysis of Java code. What I want to know is why my boss will investigate in business…… -
How to convert floating point numbers to 4 bytes in Java?
I haven't been able to convert such things: byte[] b = new byte[] { 12,24,19,17}; Become something like this: float my…… -
Java – httpurlconnection conn.getrequestproperty returns null
I'm trying to push some data to the URL of BES (mds_cs) @ h_ 502_ 2 @ when I set some request headers in my code and s…… -
Java – jtextarea auto wrap resize
So, I'm at JPanel (@ r_104_ 2419@Layout ）Jtextarea. On I also have @ R_ 104_ 2419 @ the stuffer fills the rest of the…… -
Matching non spaces in Java
I want to detect strings that contain non white space characters Now I'm trying: !Pattern.matches("\\*\\S\\*",city) Bu…… -
Java – how do I create a treemultimap from an Iterable / collection?
I'm pruning a tree Multimap and returning the same structured tree Multimap (but pruning) For example, I have differen…… -
Is there any way to force a class to use the public static final field in Java?
Is there any way to force classes in Java to have public static final fields (through interfaces or abstract classes)?…… -
java – Float vs Double
Is there a case where compare (equals()) between two floating-point values returns false if they are compared to doubl…… -
How to create JSON arrays in Java
I have a JSON structure as follows How do I create this array structure programmatically? JSON structure: { "Employee…… -
Unit test code and Java 8 Lambdas
I've been using java 8 for several months, and I've started using lambda expressions, which is very convenient in some…… -
Java – how to select from HQL
I am a novice to HQL and have an SQL expression that I need to convert, but I cannot select an SQL statement: select S…… -
Java – how to install the Tomcat plug-in in eclipse
I use eclipse as my SDK for web project, and I need Tomcat integration with eclipse I'm on my Ubuntu machine How do I …… -
Using multiple consecutive commas to separate strings in Java
See English answers > how to split a comma delimited string into an array of empty strings1 String abc = "a,b,c,d,"…… -
Java – image rotation
I tried to rotate the image I use this java code: BufferedImage oldImage = ImageIO.read(new FileInputStream("C:\\works…… -
Java – how does this division approximation using displacement operations work?
In Java util. In dualpivotquicksort, the following line of code appears: // Inexpensive approximation of length / 7 in…… -
Java Generator for Poisson and Uniform Distributions？
According to my understanding, the standard generator is used for normal distribution I have to generate random number…… -
Help is needed to find the vid / PID of the USB driver connected to the system through Java code
I need to find the supplier ID and product ID of the USB driver connected to the system through Java code. Any suggest…… -
Java – servlet forward response caller / previous page
I tried to forward the servlet response to the same page it came from (a.k.a: Previous page, or "servlet" caller) I've…… -
Java – can I select null as the column value in the HQL query?
I need a list of three columns Columns 1 and 3 have values, while column 2 is empty I need something like this: select…… -
Java – compilation failed; For more information, see compiler error output
When I try to compile build XML file, the following error is: BUILD Failed C:\Users\workspace\testrepo\src\build.xml:3…… -
Java – change JSP button click
I have a question I have three JSP pages The first is a menu with two buttons When I click the first button, I want to…… -
Java – is there any special reason for eclipse generated equals to use the values of 1231 and 1237 as Boolean values?
The title basically explains everything I tried Google search, but returned a lot of false positives I think I just wa…… -
Java – are local variables in static methods also static?
I wonder if we declare them statically, all local variables will become static? For example: public static void A(){ …… -
Strange floating point behavior in Java programs
See English answer > is floating point math broken? 29 0.0 + 0.04 = 0.04 0.04 + 0.04 = 0.08 0.08 + 0.04 = 0.12 0.12……