SEARCH KEYWORD -- import
What is the use of empty struct in GoLang
In Go, an empty struct struct{} is a struct with no fields that may appear to be of little use, but in reality, it can be useful in certain situations and become a simple and efficient solution in code. As a semaphore or lock Because the empty struct has no fields, it can be conveniently used to implement some concurrency control functions, such as mutex locks, read-write locks. We can use chan struct{} to implement an unbuffered channel for controlling concurrent access. package main import ( ...
GOLANG,EMPTY STRUCT 2024-04-05 23:54:03
Ensuring Go Interface Implementation: A Quick Guide
Introduction Go's simplicity and power shine in its interface system, offering a clean way to define contracts between types. However, when it comes to checking whether a struct satisfies an interface, Go's static typing philosophy means there isn't a direct runtime check. In this concise guide, we'll explore practical methods, including some lesser-known tricks, to verify whether a struct implements an interface. Method 1: Type Assertion and a Dummy Method package main import "fmt" type MyInt...
INTERFACE,GOLANG,IMPLEMENTS 2023-11-25 21:36:01
Java AbstractMethodError explained and demonstrated
According to Oracle Java API documentation, AbstractMethodError is a kind of runtime error where the application is having some incompatible changes which leads to a missing implementation of an abstract method. Below is the official description. Thrown when an application tries to call an abstract method. Normally, this error is caught by the compiler; this error can only occur at run time if the definition of some class has incompatibly changed since the currently executing method was last co...
JAVA,ABSTRACTMETHODERROR 2016-07-22 22:03:20
Comparable and comparator in Java
Comparable and comparator are two similar interfaces used to compare objects in Java. When we want to sort a list of objects such as Employee or User etc, we may need to implement these interfaces to make them comparable as we want. However, there are some differences between comparable and comparator interface.ComparableA comparable object is capable of comparing itself with another object. The class itself must implements the java.lang.Comparable interface in order to be able to compare its in...
Java,Comparable,Comparator,Sort 2012-07-04 12:06:15
The magic of go:linkname
When writing Go program, there is frequent need on using time.Sleep() function to pause the logic for some time. And if jumping to the definition of this function, can see below definition: // Sleep pauses the current goroutine for at least the duration d. // A negative or zero duration causes Sleep to return immediately. func Sleep(d Duration) I's strange that there is no function body defined here. What happened? The actual definition of the function body is residing at runtime/time.go&nb...
TRICKS,GO:LINKNAME,GOLANG 2022-04-10 08:39:00
Generate certificate in Java -- Self signed certificate
This is the first post in this series which I will show you how to generate SSL certificate in Java programmatically. Certificates are frequently used in SSL communication which requires the authentication of server to client. This is to make the client to trust that the server is actually the one it claims. Certificates are really important on the Internet. All HTTPS communications on the Internet need the server side to present their certificates signed by trusted CAs. The basic flow of a requ...
Java,Certificate,X509 2014-07-30 07:42:18
static nested and non-static nested class in Java
Nested classes are divided into two categories: static and non-static(inner). Nested classes that are declared static are simply called static nested classes. Non-static nested classes are called inner classes. Static class can be defined as : class OuterClass{ static class StaticNestedClass{ //OTHER STUFF } } Static nested classes are accessed using the enclosing class name: OuterClass.StaticNestedClass For example, to create an object for the static nested class, use this synta...
Java,static nested class,inner class 2014-04-23 07:11:44
Finding selected checkbox items in a JSF dataTable
This is one of those problems that I couldn’t find a complete example for when I needed it, so hopefully this will save somebody else the extra time it took me to piece it together. We frequently need to have data tables in our UI, and allow the user to select a subset of those items for action. In JavaServer Faces, this means having a DataTable, each row having its own checkbox. But when the action is triggered, how to we find which items the user has selected. The first step is to ...
JavaServer Faces,JSF,Datatable,Checkbox,Example 2012-01-03 03:02:46
Can two new objects point to the same memory address in GoLang?
Do you have any idea what the output will be for below GoLang snippet? package main import ( "fmt" ) type obj struct{} func main() { a := &obj{} fmt.Printf("%p\n", a) c := &obj{} fmt.Printf("%p\n", c) fmt.Println(a == c) } Many people would think that a and c are two different object instances which have different memory addresses. Hence a == c will be false. But if you try to run the above program, you would see below output 0x5781c8 0x5781c8 true To get to know the reason wh...
GO,GOLANG,VARIABLE ESCAPE,ZEROBASE 2019-04-06 01:19:52
Be careful about nil check on interface in GoLang
nil check is frequently seen in GoLang code especially for error check since GoLang's special error handling convention. In most cases, nil check is straight forward, but in interface case, it's a bit different and special care needs to be taken. Take a look at below code snippet and guess what the output will be. package main import ( "bytes" "fmt" "io" ) func check(w io.Writer) { if w != nil { fmt.Println("w is not nil") } fmt.Printf("w is %+v\n", w) } func main() { var b *bytes.B...
INTERFACE,GOLANG,NIL CHECK,NIL TYPE,NIL VALUE 2019-04-06 07:47:07
RECENT
- The Role of Coding Skills in Advancing Tech Careers
- Tips for Socializing With Friends During College
- Proximity Cards Do More Than Just Open Doors
- How to choose quality painted auto parts
- Oval engagement rings from MoonOcean: Elegance of form and individual approach
- Hologres vs AWS Redshift
- GoLand connect to Hologres
- A journey to investigate a goroutine leakage case
- Understanding Slice Behavior in Go
- Breaking Barriers: How 3D Printing is Democratizing Product Development
- more>>