Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Articles by raja
Page 25 of 38
What are the different startup scripts in JShell in Java 9?
JShell is an interactive Java Shell tool that executes code from the JShell and instantly displays an output. JShell is the REPL (Read-Evaluate-Print-Loop) tool that can run from the command-line prompt.In JShell, there is an option to load a script on startup that includes some special predefined options. These can be specified using the "--startup" flag passing in either a filename or one of DEFAULT, JAVASE, and PRINTING. We can use "/list -start" comamnd to see all startup snippets to be evaluated.DEFAULT: It loads the default behavior. This acts the same as if this is not specified at all.JAVASE: It ...
Read MoreWhat are the different "/edit" commands in JShell in Java 9?
JShell is a command-line tool introduced in Java 9 that evaluates declarations, statements, and expressions without the main() method. JShell can set up a text editor called JShell Edit Pad, which allows us to modify the code very easily, and it can be launched using the "/edit" command.Below are the different "/edit" commands used in Jshell./edit /edit [ID] /edit [Code_Name]/edit: This command can be used without an argument, the "/edit" command displays all the active code in the text editor./edit [ID]: This command displays in the text editor the code corresponding to the ID entered./edit [Code_Name]: This comamnd displays in the ...
Read MoreHow to get JShell documentation in Java 9?
Java 9 introduced a new interactive tool called JShell. This tool can be used to execute expressions, classes, interfaces, enums, and etc.The detailed documentation can be available in JShell with full information, as well as the use of its internal commands with the various options. This documentation can be accessed using two commands: "/help" and "/?". JShell's documentation is not only limited to information regarding its internal controls, and also includes Javadoc.In the below code snippet, the result can be obtained by using the "/help" command.jshell> /help | Type a Java language expression, statement, or declaration. | Or ...
Read MoreHow can we implement Flow API using Publisher-Subscriber in Java 9?
Flow API (java.util.concurrent.Flow) has introduced in Java 9. It helps to understand different ways in which the Publisher and Subscriber interfaces interact to perform desired operations.Flow API consists of Publisher, Subscriber, Subscription, and Processor interfaces, which can be based on reactive stream specification.In the below example, we can implement Flow API by using Publisher-Subscriber interfaces.Exampleimport java.util.concurrent.Flow.Publisher; import java.util.concurrent.Flow.Subscriber; import java.util.concurrent.Flow.Subscription; public class FlowAPITest { public static void main(String args[]) { Publisher publisherSync = new Publisher() { // Create publisher @Override public void subscribe(Subscriber
Read MoreHow to modify the default editor of JShell in Java 9?
JShell implements REPL (Read-Evaluate-Print Loop) that reads the code from the command-line, evaluates the given snippet, and prints the result back to us.In JShell, it's possible to edit code from the default JShell editor by using JShell Editor Pad. We can also use the "/set" command to modify the default editor in order to define another one. When launching the "/edit" command, this editor can be used. In order to perform this operation, we can simply launch the "/set editor [editor]" command.Suppose we want to set the Notepad application as the default program for editing code, then just type the ...
Read MoreHow can we modify an existing module in Java 9?
The module is a named, self-describing collection of code and data. The code has been organized as a set of packages containing types like Java classes and interfaces. The data includes resources and other kinds of static information. We need to declare a module then add module-info.java at the root of the source code.Below is the template of the "module-info.java" file.module { requires ; requires ; exports ; exports ; exports to }We can use certain command-line options that help us to modify existing modules and add dependencies to them, export ...
Read MoreWhat are the different "/vars" commands in JShell in Java 9?
JShell is an interactive command-line tool introduced in Java 9. It is also called a REPL tool that takes input, evaluates it, and prints output to the user.In the JShell tool, it's possible to list all variables created by using the internal command "/vars". We have different "/vars" commands available in the JShell tool as listed below./vars /vars [ID] /vars [Variable_Name] /vars -start /vars -all/vars: This command allows to us display the list of all active variables of the current session./vars [ID]: This command displays the variable and its value, corresponding to the entered ID. This ID corresponds to the ...
Read MoreHow can we create a Service Provider interface in Java 9?
A module that provides the implementation for the Service interface contains a "provides" statement in the module descriptor file. If the module doesn’t have the "provides" statement in the module descriptor file, the service loader can't load that module.We can create the Service Provider Interface by using below steps:We create a new Module com.tutorialspoint.serviceproviderinterface.In the src/main/java directory, we create "module-info.java" file.Inside our source directory, we create the package com.tutorialspoint.serviceproviderinterface.spi.Finally, we create the interface ServiceProviderInterface that contains a method: printServiceName() to be implemented.In the below, we can define Service Provider Interface.package com.tutorialspoint.serviceproviderinterface.spi; public interface ServiceProviderInterface { void printServiceName(); }
Read MoreWhat is the importance of jmod format in Java 9?
Java 9 has introduced a new format called "jmod" to encapsulate modules. The jmod files can be designed to handle more content types than jar files. It can also package local codes, configuration files, local commands, and other types of data. The "jmod" format hasn't support at runtime and can be based on zip format currently. The jmod format can be used at both compile and link time and can be found in JDK_HOME\jmods directory, where JDK_HOME is a directory. The files in jmod format have a ".jmod" extension.Java 9 comes with a new tool called jmod, and it is located in the ...
Read MoreWhat are the different "/types" commands in JShell in Java 9?
JShell tool has introduced in Java 9 version. It is also called a REPL(Read-Evaluate-Print-Loop) tool that allows us to execute Java code and getting immediate results. We need to list out the declared types like class, interface, enum, and etc by using the "/types" command.Below are the different "/types" commands in JShell./types /types [ID] /types [Type_Name] /types -start /types -all/types: This command lists all active types (class, interface, enum) created in JShell./types [ID]: This command displays the type corresponding to the id [ID]./types [Type_Name]: This command displays the type corresponding to [Type_Name]./types -start: This command allows us to list the ...
Read More