DEV Community: abhisheks-12

Adding SSL Certificate to JVM in order to access HTTPS

abhisheks-12 — Tue, 12 Jul 2022 13:12:33 +0000

1. Export Certificate from url.

1) Click on view site information icon.

2)Click on connection is secure icon .

3) After that click on Certificate is valid.

4) Now go to certificate and click on details tab.

5) Click on Copy to File and then okay. After that Certificate Export Wizard will open , now click on Next button.

6) Now select DER encoding and click on next.

7) Provide file path. Where you want to export and then click on next.

8) Now click on finish to complete export.

2. Add certificate to java key store

1) Now rum cmd as administrator.
2) Navigate to java bin folder.

3) Now Enter following commands on cmd -
keytool -importcert -file <filepath of certificate> -alias <certificate name> -keystore "C:\Program Files\java\jdk-11.0.13\lib\security\cacerts"

4) Example -
keytool -importcert -file C:\Demo\ssl.cer -alias ssl -keystore "C:\Program Files\java\jdk-11.0.13\lib\security\cacerts"

5) Now after entering command it will ask for password and password is changeit.

6)Now restart your JVM.

Java Script Array Methods

abhisheks-12 — Sat, 16 Oct 2021 17:51:21 +0000

Array is data structure in which we store different collection of data. Now we are going to see array methods.

1) ForEach- For looping over array we use ForEach method,
it will access every element individually and it takes callback function.

2) Map - It will create new array without changing original array. Suppose we want multiply each number by two from given array and push it in new array , we can do it easily with help of map.

3) Filter - with help of filter method we easily filter some elements from array . suppose we want to take numbers only smaller than 2.

4) Reduce - Suppose we have array which contains number and we want sum of those numbers. Here we can use reduce method which takes call back function and accumulator. We add accumulator and current number and at end of loop it takes accumulators value

5) Push - It will add element at end of array.

6) Pop - It will remove last element of array.

7) Indexof - It simply gives index of given element

8) Reverse - It will reverse array.

9) Includes - If value is present in array it will give us true else false.

10) Join - It will join array and convert it into string

Read Data From Firebase Firestore (V9)

abhisheks-12 — Sat, 16 Oct 2021 13:25:31 +0000

For reading data from firestore database we will need some starter files so clone this repo https://github.com/abhisheks-12/Blog-dev-to

1) Go to https://firebase.google.com/ then click on Go to console.

2) Now create project with name parking system and after that turn off google analytics.

3) After that click on </> icon which represents web app.

4) Register app with any name , then copy firebase configuration and if you don't have firebase install firebase first.

5) After that go to your editor open src/Firebase/config.js
and paste configuration here

6) Again go to firebase click on firestore database.

7) Click on start collection and create your data base like this
picture

8) Now come back to your text editor open src/App.js.

9)Import following statements

10) Now we will fetch data from firestore so we will use async function so first see this code

11) Here we are using getData function to fetch data ,now we will save data in parkingData first console log parkingData after logging we will find doc value in this value there will be objects of our data.

12) In setCars we are setting data in array using map method . All properties will come in different objects so we are destructuring
this properties into one object with unique id .

15) Now we have data and now we are going to loop over that data
using map and access every property and set it in our html .

16) Here is final code https://github.com/abhisheks-12/Blog-dev-to/tree/final/src

React useState

abhisheks-12 — Sun, 10 Oct 2021 18:05:35 +0000

Hey guys this is my first blog...

Suppose we have to render name in react app . We can save that name in simple variable and render that name .

But what if we want to change name to Alfred after clicking Change Name button , so let's pass changeName function . In changeName function if we change value of variable name to Alfred that's not going to work.

So here we use useState hook .
for using useState hook first we need to import it from react.
Example-
1.import { useState } from "react";

With help of useState we set two variables like

Here name variable represents Bruce , after that in changeName function we use setName variable to set name to Alfred.

now after click name will change to Alfred. We can pass different type of data in useState hook.