Java Snippet

In programming, the snippet is a piece of code that resolves a bunch of problems with a few lines of code. Also, reduces the line of code and make programmer more knowledgeable. In this section, we will discuss what is a snippet in Java, its uses, and example. Also, we will focus on the Java Snippet class, methods, and nested subclasses.

Before moving to the snippet in Java, first, we have to understand JShell (Java Shell).

JShell

JShell is abbreviated for the Java Shell tool. It is an interactive tool that helps programmer to learn Java programming language and prototyping of the Java code. It is a Read-Eval-Print Loop (REPL) that evaluates declarations, statements, and expressions as they are entered and immediately shows the results. The tool can be run from the command line.

Uses of JShell

JShell tool allows programmers to enter program elements one at a time and at the same time one can see the result. Also, allows us to make adjustments accordingly. Typically, a general Java program development involves the following process.

Write any Java program
Compile it, fix errors (if any)
Run the program
Getting correct output. If no, figures out what is wrong with it
Edit it
Repeat the above process

Apart from the above, it helps the programmer to try out code easily and also explore possible options for our program. Another benefit of using JShell is that it allows us to test an individual statement, try out various versions of a function, and more.

Once we develop the program, paste code into the JShell tool to try it out. After that, paste the working code into the program editor or IDE from JShell tool.

What is a snippet in Java?

As we discussed above JShell accepts statements, variables, methods, expressions, class definitions, and imports. These fragments (part or pieces) of Java code are called snippets. In general, the snippet is a section or piece of Java source code that save in XML format.

Example of Snippet

Suppose, we have to create a Java program to calculate the factorial of a number. Instead of writing complete Java source code, we can write the logic (main section of the source code) section, as follows.

The following code snippet depicts the recursive function for calculating the factorial of a number.

int factorial(int n) {
 if (n <= 1)
 return 1;
 else
 return (n * factorial(n ? 1));
}

Note: Snippet and pseudo-code can be used in the same context but both are different in meaning. Pseudocode just represents principle, but doesn't use real, usable syntax. While snippet uses proper syntax.

Components of a Snippet

Each snippet contains the following four components:

Name of the snippet: Snippet name make it unique from different snippets.
Prefix: The keyword which generates current snippets in the program.
Body: It represents the actual code (logic) that we bind into snippets contained in the body.
Description:Information about the snippet contains in a snippet.

Format of the Snippet

The snippet of particular code implemented in the java.json file that uses JSON format.

"Name_of_the_snippet ":
{					
"prefix": "prefix_of_the_snippet",		
"body": [
		// Actual code of the snippet
		],
"description": "description_about_the_snippet"
}

Creating Snippets in Java

There are the following two steps involved in creating a snippet of Java code.

Create a Java class for which you want to create a snippet.
Create a snippet of this Java class.

Create a .java file. In our case, we have created a file in which we have calculated factorial.

FactorialExample.java

public class FactorialExample
{  
static int factorial(int n)
{    
if (n == 0)    
return 1;    
else    
return(n * factorial(n-1));    
}    
public static void main(String args[])
{  
int i,fact=1;  
int number=4;//It is the number to calculate factorial    
fact = factorial(number);   
System.out.println("Factorial of "+number+" is: "+fact);    
}  
}  

Output:

Factorial of 4 is: 24

Create a Snippet of the Java File

In order to generate snippets, we will use VS Code text editor. The editor supports development operations and a version control system.

Note: Moving ahead, ensure that VS Code editor is properly installed in your system.

Follow the steps given below:

Step 1: Open VS Code in a folder to be created.

Step 2: Click on the Setting icon placed at the bottom left corner. It shows a pop-up menu. From the menu, click on the User Snippets option.

Step 3: In the search box, type java.json and press enter.

After hitting the Enter key, it opens the java.json file. It looks like the following.

Step 4: Now, go to Google and search Snippet generator. It is a tool that converts Java code into snippets. The tool looks like the following.

Step 5: Paste your Java code into the left block. In our case, we have pasted Java code that calculates the factorial of a number.

FactorialExample.java

class FactorialExample
{  
 static int factorial(int n){    
  if (n == 0)    
    return 1;    
  else    
    return(n * factorial(n-1));    
 }    
 public static void main(String args[]){  
  int i,fact=1;  
  int number=4;//It is the number to calculate factorial    
  fact = factorial(number);   
  System.out.println("Factorial of "+number+" is: "+fact);    
 }  
}  

After pasting the Java code, the window looks like the following.

Also note, in the above window there are the boxes one is for Description and the second for Tab trigger. In the description box, we have written CalculateFactorial which denotes the name of the snippet. In the Tab trigger box, we have written FindFactorial which represents keywords to generate.

Step 5: At last, copy the snippet of the Java code by clicking on the Copy snippet button and paste it into the java.json file (that we have searched in Step 3) in VS code.

java.json

"CalculateFactorial": {
  "prefix": "FindFactorial",
  "body": [
    "class FactorialExample",
    "{  ",
    " static int factorial(int n){    ",
    "  if (n == 0)    ",
    "    return 1;    ",
    "  else    ",
    "    return(n * factorial(n-1));    ",
    " }    ",
    " public static void main(String args[]){  ",
    "  int i,fact=1;  ",
    "  int number=4;//It is the number to calculate factorial    ",
    "  fact = factorial(number);   ",
    "  System.out.println(\"Factorial of \"+number+\" is: \"+fact);    ",
    " }  ",
    "}  "
  ],
  "description": "CalculateFactorial"
}

In the same way, we can also generate snippets for other Java source codes.

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