Java
-
JPA – SQL query using Union and select constants equivalent to SQL query
I wrote an SQL query that basically selects from many tables to determine which tables have rows created since a speci…… -
Rescale vector R
Suppose I have an integer vector, for example: > x [1] 1 1 1 4 4 13 13 14 I'm looking for an effective way to …… -
Java – an example of barrier decomposition
I'm reading the Book Java concurrency in practice, Can someone give an example of how it decomposes the problem into m…… -
Java – use generics to return multiple types
I have this method – public List<Apples> returnFruits(String arg1){ List<Apples> fruits = new ArrayList<…… -
Java Swing: add jlabel to JPanel
I just want to add jlabel to the existing JPanel It looks simple. I searched everywhere I think this is right, but the…… -
Java – when using “. Get (0)” in an empty list, I get an out of bounds exception instead of null?
So in my homework, for my error checking test, I made a list < someobject > and I got an indexoutofboundsexcepti…… -
Java – the program does not display the desired string representation of the object
I created a program in Java that should return all orders to the provider This is the procedure: package sakila.ui; i…… -
Java – if you use the Boolean Android statement
I've encountered Boolean problems in if statements all day. Now I'm really bothering me! I've seen other Android threa…… -
Java – how to change the JFrame content to the corresponding click?
I am using java to develop a simple desktop application There is a menu bar. When the user clicks menu item 1, the con…… -
How to disable all network connections in Java
Is there any way to run Java VM (Java. Exe) on Windows Server 2008 and disable all network connections using command l…… -
Java – J2EE: Singleton vs saving things in a session
When should I keep an object (that is, an application wide property file) in the session instead of creating a singlet…… -
Java – how to find the maximum value in a binary tree
I have to complete the method maxelem (node) in this way, and the method maxelem () returns the maximum value containe…… -
Java – retrieves the number of types in the list
I have a list The list can contain multiple items of the same enumeration type Let's say I have an enumeration: toy is…… -
How do I create a copy of the data type I created in Java?
If I have a class: public class MyType { private List<Integer> data; private boolean someFlag; …… -
Java – Eclipse: some or all of the projects cannot be imported because they already exist in the workspace
Sorry, I know I often ask this question But the non scene suits my problem I use eclipse in Git (in win7) In the GIT b…… -
In Java, can I use conditional expressions to “select” reference types?
Can I use conditional expressions to "select" reference types, as shown below? ??? = isTrue() ? Integer : Double; What…… -
Convert CIDR notation to IP range in Java
See the English answer > converting CIDR address to subnet mask and network address 11 For example, for CIDR 192.16…… -
Java – how to use spring roo to create @ entity without @ version field?
I use spring roo and JPA (hibernate) as my entity model I don't want to have a @ version field in some entities How ca…… -
How to use java to find data in small data sets?
We have to find some data according to three input data fields Search must be fast There are only about 20 possible se…… -
How to override generic list return types in Java
I tried to override a method whose return type is a list in a subclass, as shown in the following example. Due to gene…… -
Strange Java HashMap behavior – no matching object found
When I tried in Java util. When I found a key in HashMap, I encountered some strange behavior. I think I missed someth…… -
Java findbugs: suspicious comparison of long references
Findbugs identified the following error in my code: @ h_ 404_ 7@ if (materialDeFinition.getId() == deFinitionToRemoveF…… -
Java – when deploying spring app in Tomcat 6, an “access denied” message appears
When I tried to deploy my spring application on Tomcat 6, I received an error message java.util.logging.errormanager:4…… -
Java – what did I do wrong with this quadratic formula?
a = 1,b = -7,c = 12 a = 1,b = -7,c = 12 public static void quadratic(double a,double b,double c){ double r1; …… -
Java – a term that distinguishes between “default” and “makeup” classes in OOP
ArrayLists, buffer readers, scanners, etc All default classes that already exist in the language Unlike the public cla…… -
Java – regular expression or exception handling?
Which of the following is better to check whether the string is floating? try{ Double.parseDouble(strVal); }catch(Num…… -
Java – how to add icons to items in the navigation drawer
I want to place icons next to items in my navigation drawer. I have set such icons: Titles = getResources().getStringA…… -
How to use java to find data in small data sets?
We have to find some data according to three input data fields Search must be fast There are only about 20 possible se…… -
Datamapper – doctrine2 best practice, should entities use services?
I answered a similar question: using the data mapper pattern, should the entities (domain objects) know about the mapp…… -
Java – declare anonymous inner classes
rb.addActionListener(new ActionEvent(ae) { rb.addActionListener(new ActionEvent(ae) { public void actionPerformed(A…… -
Java says this method has a constructor name
I want to return the value of my array plus the return value of the recursive call But for some reason, Java doesn't w…… -
Parsing timestamp with time zone in Java?
I'm trying to parse a string of time stamps using the time zone obtained from DB The string is as follows: SimpleDateF……