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Android open json file

Содержание
  1. Android — How to Read and Write (Parse) data from JSON File ?
  2. Kotlin Android – Read JSON file from assets using Gson
  3. Where to put assets folder and JSON file
  4. Create Data Class
  5. Create function for reading JSON file from assets
  6. Parse JSON using Gson
  7. Gson.fromJson() method
  8. Add Gson to Android project
  9. Parse JSON string to Kotlin object
  10. Conclusion
  11. Java Android – Read JSON file from assets using Gson
  12. Where to put assets folder and JSON file
  13. Create Java Data Class
  14. Create function for reading JSON file from assets
  15. Parse JSON using Gson
  16. Gson.fromJson() method
  17. Add Gson to Android project
  18. Parse JSON string to Java object
  19. Conclusion
  20. Android — JSON Parser
  21. JSON — Elements
  22. JSON — Parsing
  23. Example
  24. How To Open A JSON File On Windows, Mac, Linux & Android
  25. What Is A JSON File Format?
  26. Advantages Of JSON Format
  27. Uses Of JSON File
  28. How To Open JSON File?
  29. A) Windows
  30. #1) File Viewer Plus
  31. #2) Altova XMLSpy
  32. #3) Microsoft Notepad
  33. #4) Microsoft WordPad
  34. #5) Notepad++
  35. #6) Mozilla Firefox
  36. B) Mac
  37. #1) Apple TextEdit
  38. #2) BBEdit
  39. #3) MacVim
  40. C) Linux
  41. #1) Vim
  42. #2) PICO
  43. #3) GNU Emacs
  44. D) Android
  45. #1) File Viewer for Android
  46. Conclusion

Android — How to Read and Write (Parse) data from JSON File ?

Mar 15, 2020 · 4 min read

How to Insert, Update and Delete the data available in JSON File in Android ?

Android provides several ways of dealing with app data within the system or local storage. We are going to be dealing with app-specific storage of data in directory available in Internal or External Storage of system.

  • Internal Storage : Sensitive data, No other application access it.
  • External Storage : Other application can access it like Images.

What we are going to do ?

We will generate a JSON file, which will be stored in Internal storage of application. From android application user will add( WRITE) data, which will be converted into JSON format(JSON Object) and then stored in JSON file.

We w i ll access( READ) the data from JSON file and converted into app usable format like string, arrays etc.

We will also UPDATE the data from JSON file and save it back to JSON file.

We will also perform the DELETION operation on JSON file data/Objects.

Data will be taken in terms of Java Object and transferred to JSON File.

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Kotlin Android – Read JSON file from assets using Gson

In this Kotlin-Android tutorial, I will show you how to read and parse JSON file from assets using Gson.

Where to put assets folder and JSON file

You will need to create the assets folder inside src/main, next to your java and res folder. Then make sure that your JSON file is within your assets folder.

For example, bezkoder.json file contains list of people data like this.

Create Data Class

Let’ create Person class with 3 fields: name, age, messages.

Create function for reading JSON file from assets

We’re gonna create a Utils class and add the function that will read JSON file from assets.

The function has 2 parameters: context & fileName .
– We get AssetManager object from context by context.assets , then use AssetManager.open() method to open a file in assets folder using ACCESS_STREAMING mode, it returns an InputStream .
– Then bufferedReader() creates a buffered reader on the InputStream and readText() helps us to read this reader as a String.

Parse JSON using Gson

Gson.fromJson() method

com.google.gson.Gson package provides fromJson() for deserializing JSON.

  • T : type of the desired object
  • json : could be a JsonElement object, a Reader object or a String
  • classOfT : class of T
  • typeOfT : specific genericized type

Add Gson to Android project

Gson is a Java/Kotlin library for converting JSON string to an equivalent Java/Kotlin object.
Open build.gradle file and add Gson library.

Parse JSON string to Kotlin object

In your activity, import Gson library and call getJsonDataFromAsset() .

Check Android Logcat, you can see:

In the code above, we use Gson.fromJson() method to parse JSON string to List

For more details about ways to parse JSON to Data Class object, to Array or Map , please visit:
Kotlin – Convert object to/from JSON string using Gson

Conclusion

Let me summarize what we’ve done in this tutorial:

  • put assets folder & JSON file in the right place
  • create data class corresponding to JSON content
  • use AssetManager to open the File, then get JSON string
  • use Gson to parse JSON string to Kotlin object

Источник

Java Android – Read JSON file from assets using Gson

In this Java-Android tutorial, I will show you how to read and parse JSON file from assets using Gson.

Where to put assets folder and JSON file

You will need to create the assets folder inside src/main, together with java and res folder. Then put JSON file inside assets folder.

For example, bezkoder.json file contains list of people data like this.

Create Java Data Class

Let’ create User class with 3 fields: name, age, messages.

Create function for reading JSON file from assets

Let’s a Utils class and add a static function that will read JSON file from assets.

You can see that getJsonFromAssets() function has 2 parameters: context & fileName .
– We get AssetManager object from context by context.assets , then use AssetManager.open() method to open a file in assets folder using ACCESS_STREAMING mode, it returns an InputStream .
– Then we use InputStream.read() to read data into byte[] buffer and readText() to transform the buffer into a String.

Parse JSON using Gson

Gson.fromJson() method

com.google.gson.Gson package provides fromJson() for deserializing JSON.

  • T : type of the desired object
  • json : could be a JsonElement object, a Reader object or a String
  • classOfT : class of T
  • typeOfT : specific genericized type
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Add Gson to Android project

Gson is a Java library for converting JSON string to an equivalent Java object.
Open build.gradle file and add Gson library.

Parse JSON string to Java object

In your activity, import Gson library and call getJsonFromAssets() .

Now, open Android Logcat window and you can see:

Conclusion

Let me summarize what we’ve done in this tutorial:

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Android — JSON Parser

JSON stands for JavaScript Object Notation.It is an independent data exchange format and is the best alternative for XML. This chapter explains how to parse the JSON file and extract necessary information from it.

Android provides four different classes to manipulate JSON data. These classes are JSONArray,JSONObject,JSONStringer and JSONTokenizer.

The first step is to identify the fields in the JSON data in which you are interested in. For example. In the JSON given below we interested in getting temperature only.

JSON — Elements

An JSON file consist of many components. Here is the table defining the components of an JSON file and their description −

In a JSON file , square bracket ([) represents a JSON array

In a JSON file, curly bracket (<) represents a JSON object

A JSON object contains a key that is just a string. Pairs of key/value make up a JSON object

Each key has a value that could be string , integer or double e.t.c

JSON — Parsing

For parsing a JSON object, we will create an object of class JSONObject and specify a string containing JSON data to it. Its syntax is −

The last step is to parse the JSON. A JSON file consist of different object with different key/value pair e.t.c. So JSONObject has a separate function for parsing each of the component of JSON file. Its syntax is given below −

The method getJSONObject returns the JSON object. The method getString returns the string value of the specified key.

Apart from the these methods , there are other methods provided by this class for better parsing JSON files. These methods are listed below −

Sr.No Component & description
1

This method just Returns the value but in the form of Object type

This method returns the boolean value specified by the key

This method returns the double value specified by the key

Sr.No Method & description
1
4 getInt(String name)

This method returns the integer value specified by the key

This method returns the long value specified by the key

This method returns the number of name/value mappings in this object..

This method returns an array containing the string names in this object.

Example

To experiment with this example , you can run this on an actual device or in an emulator.

Steps Description
1 You will use Android studio to create an Android application.
2 Modify src/MainActivity.java file to add necessary code.
3 Modify the res/layout/activity_main to add respective XML components
4 Modify the res/values/string.xml to add necessary string components
5 Run the application and choose a running android device and install the application on it and verify the results

Following is the content of the modified main activity file src/MainActivity.java.

Following is the modified content of the xml HttpHandler.java.

Following is the modified content of the xml res/layout/activity_main.xml.

Following is the modified content of the xml res/layout/list_item.xml.

Following is the content of AndroidManifest.xml file.

Let’s try to run our application we just modified. I assume you had created your AVD while doing environment setup. To run the app from Android studio, open one of your project’s activity files and click Run icon from the toolbar. Android studio installs the app on your AVD and starts it and if everything is fine with your setup and application, it will display following Emulator window −

Above Example showing the data from string json,The data has contained employer details as well as salary information.

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How To Open A JSON File On Windows, Mac, Linux & Android

This Tutorial Explains What is a .JSON File Format and Discusses Various Softwares Tools to Open a JSON File in Windows, Mac, Linux & Android:

Most of you must have struggled to open a JSON file at some point in time.

In this tutorial, we will discuss all about the JSON files, what they are, why they are used and how can you open them in detail.

Let’s Explore!!

What You Will Learn:

What Is A JSON File Format?

The structures of simple data sets are stored in JavaScript Object Notation or JSON format. It is based on text, is lightweight, has a format that humans can read, and is a standard data interchange format. It contains a .json file extension and is similar to the XML file format.

It was initially JavaScript subset-based. But it is considered to be a format that is language independent and is supported by many programming APIs. It is used in the programming of Ajax Web application commonly and today it has become a popular alternative to XML.

Although many applications use JSON to interchange data, not many save it. Its because the interchange occurs between the computers that are connected with the internet. But some applications like Google+ make the users be able to save .json files. Google+ uses JSON files to save profile data.

You can download your Profile data by choosing the data liberation page and select the option of downloading your profile data.

Firefox also uses the .json file extension to contain the backup copy of bookmarks that users create. If you lose your bookmark information, you can recreate it using the information from the JSON file.

Advantages Of JSON Format

Enlisted below are some of the advantages of JSON.

  • It is compact.
  • Both people and computers can easily read and write this file.
  • It easily maps onto the data structures that most programming languages use.
  • Almost every programming language contains libraries or some function that can read and write the JSON structures.

Uses Of JSON File

The main purpose of the JSON file was to transmit data between a server and a web application. But today, it serves many purposes.

  • File Configurations: Many JavaScript applications like reactJS, node.js, and others that are server-based use this file to store configuration information.
  • Storing Data: MongoDB and other NoSQL database engines use it to store structured data in their database.
  • Application and Notification: JSON delivers notifications to a server from the web applications. The web applications also use it to download the web application state.

How To Open JSON File?

JSON is a plain text file that can be opened in a text editor. You can easily modify and save it back without any special software. But the chances are that you might break the formatting and any error in formatting will result in failure of the application during the loading of the JSON file.

That’s why we recommend you to use an application to open and edit the file so that you don’t mess with its formatting.

Here are the programs that can help you open the JSON file.

A) Windows

#1) File Viewer Plus

File Viewer Plus is a universal file opener for Windows with which you can view, convert, save, and edit over 300 different file formats. It is easy to use and you can use the advanced image editor to save and edit images.

It will display metadata and hidden information of the file for each one you open. If, in a rare case, if there is a file format that it doesn’t support, you can still use the Text view or Hex view to view the contents of the file.

Price: Free

#2) Altova XMLSpy

Altova XMLSpy is the world’s best-selling XML and JSON editor. This commercially licensed product is meant only for Windows. It offers many features like a text and grid view for XML editing, Graphical editors, XML instance editing and documentation, etc.

It is one powerful tool for opening and editing JSON files. Developers can build the most sophisticated applications using the tools XMLSpy and XML Editor.

Supported file types: .XML, .DTD, .JSON, .RDF, .XQ, .XQL, .XQM, .XQUERY, .XSD, .XSL, .XQY

Price:

  • Professional XML Editor: $476 approximately (€439.00)
  • Enterprise XML Editor: $866 approximately (€799.00)

Website: Altova XMLSpy

#3) Microsoft Notepad

We are all aware of a notepad. It is a simple and fast text editor on WIndows for over three decades. Here you can view and edit a plain document along with searching through it and source code files as well in an instant.

It has limited features and you can only do basic formatting. But it still is useful for many things. You can take notes, view text files, edit source code files with Notepad and that’s why it is a popular text editor.

Supported file types: .CFG, .CONFIG, .CSS, .CSV, .HTML, .INF, .INFO, .INI, .JS, .LOG, .XML,

Price: Free

#4) Microsoft WordPad

It is a simple text editor that comes with Microsoft Windows. It is almost similar to MS Word but with lesser capabilities. However, it offers rich formatting options where you can choose different fonts, customize how the text is arranged, set line spacing, etc. You can also link or embed objects.

It also comes with some convenient features like the ability to send a document in email quickly. It also supports JSON, XML, DOCX format. So you can open and edit these file formats in MS WordPad.

Supported file types: .TXT, .CFG, .CONFIG, .CSS, .CSV, Microsoft Word Document, WordPad Document, .DOCX, .HTML, .INI, .JSON, .LOG, .ODT, .RTF, .WPC, .XML.

Price: $0.99

#5) Notepad++

Notepad++ is a source code editor that supports various languages like C++, Java, YAML, PASCAL, and HTML. It can also be used as a text editor for JSON, XML, etc. It has an efficient interface that also supports plugins for additional functionality.

It is made of split-screen editing and a tabbed document interface with drag and drop function. Don’t get it confused with Notepad and it doesn’t come bundled with Microsoft.

Supported file types: .TXT, .AS, .CMD, .CS, .CSS, .DIZ, .HTML, .JSON, .LST, .LUA, MATLAB Source Code File, Mathematica Input File, .MARKDOWN,.ML, .MXML, .PAS, PHP, .PY, .SH.

Price: Free

Website: Notepad++

#6) Mozilla Firefox

It is the most popular open-source web browser and is said to be the most customizable of all the browsers. It comes with various security features like enhanced tracking protection where you can see the numbers of blocked data-collecting trackers.

With its Lockwise feature, you can sync the passwords across all your devices. It will also notify you if some data breach has compromised your confidential information.

As we have discussed earlier, Firefox uses JSON files to create a copy of bookmarks. So, you can use Firefox to open JSON files as well and not just in Windows, but in Mac and Linux too.

Supported file types: .HTML, .BAK, CHM, .CSS, .JP2, .JPEG, .JPX, .JS, .JSON, .JSP, .MAFF, .MAR, .MFL, .MHT, .MHTML, MJPG, MNG, .OGG, .PART, .RSS, .SESSION, .SLT, .URL, .VTT, .WEBP, .XHTML, .XPI, .XPT.

Price: Free

B) Mac

#1) Apple TextEdit

Apple TextEdit comes bundled with Mac OS X and is an open-source text editor. It is a simple program that you can use for reading and editing JSON, XML, OpenDocument, text documents, etc. It also reads and writes .RTF files.

You can also insert video, audio, and graphic files into the document and convert it into RTFD format. With TextEdit, you can also read and write some character encodings like Unicode, Western, and Traditional Chinese.

Supported file types: .RTF, .CFG, .CONFIG, .CSS, .CSV, .DOC, .DOCX, HTML, .INFO, .LOG, .ODT, .RTFD, .TXT.

Price: Free

#2) BBEdit

Formerly known as Bare Bones TextWrangler, BBEdit is primarily used for editing source code and is a free text editor. It provides a lot of basic text editing features along with the features that are useful for programming.

BBEdit offers function navigation and syntax highlighting for various program languages. You can use it for composing and editing plain-text files. It also provides a clean interface and convenient integration with OS X.

Supported file types: .TXT, .ANS, .BBLM, .C, .FTN, .HTML, .INC, .JSON, .PHP, .PM, .RB, .TEXTFACTORY, .UTF8

Price: Free

Website: BBEdit

#3) MacVim

If you are a user of OS X 10.6, 10.7, and 10.8, you will find MacVim as a useful source code editor and a powerful tool for programming needs. But it won’t work with Mac OS X 10.9 Mavericks.

Its graphical interface makes editing the source code more convenient. It supports many programming languages and is highly customizable.

Supported file types: .VIMRC, .A, .ASM, .ASP, .ASPX, .AWK, .BAS, .BSH, .C, .CONF, .CPP, .CS, .CSH, CSS, .F, .H, .HPP, .HS, .HTML, .JAVA, .JS, .JSON, .JSP, .LHS, .M, .M4, .MD, .PAS, .PHP, .PL, .PROPERTIES, .PY, .RB, .SH, .SQL, .SWP, .TXT, .VB, .XML

Price: Free

Website: MacVim

C) Linux

#1) Vim

Vim is yet another open-source text editor that was meant for editing source code. It is extensively customizable and is not meant for inexperienced users. It can be used with either a graphical user interface or a command user interface.

It allows you to customize key mapping and then use them to automate work. It compares the files and merges them. It also has many plugins that add to the functionality of this program.

If you are an expert in using computers and like to use apps with minimal GUI interference, then Vim is a good choice for opening various files like JSON and text editing.

Supported file types: .TXT, .A, .ANS, .ASM, .AWK, .BSH, .BVH, .C, .CELX, .CFG, Wesnoth Markup Language File, .CGI, .COMMAND, .CONF, .CSH, .DXL, .ERR, .EXW, .GVIMRC, .H, .HS, .INC, .JAVA, .JSON, .L, .LHS, .LUA, Mercury Source Code File, Objective-C Implementation File, .MARKDOWN, .MD, .ML, .MXML, .P6, .PHP3, .PROPERTIES, .RPY, .RST, .S, .SH, .SQL, .TEX, .UTF8, .YML

Price: Free

Website: Vim

#2) PICO

PICO or Pine Composer is a text editor for UNIX that offers various text editing features like cut and paste, spell check, text justification, and searching. You can use the control key sequences for editing commands. You can also configure the functionality of this text editor like function keys, search and replace, and mouse support.

Linux users use PICO to compose and edit files in plain text. It only offers basic editing capabilities but you can customize it according to your need.

Supported file types: .TXT, .ASM, .CONF, .EX, .JSON, .MAN, .ME, .OPTS, .S, .UNX

Price: Free

Website: PICO

#3) GNU Emacs

This open-source text editor is compatible with Linux, Windows, and OS X as well. With GNU Emacs, you can not only edit the plain text but also test programs along with managing files and playing games like Tetris too.

This simple text editor is used for editing web pages, source code, directory listings, email messages, and shells. GNU Emacs operates through keystroke commands for editing and automating tasks for more efficient and quick work.

This program also works as IDE, so you can compile, run, and test programs. You can also use it as a file manager but its most prominent feature is that you can customize the program according to your need.

You can save macros to automate repetitive tasks and use Emacs Lisp language for altering and extending almost any feature within Emacs.

Supported File Types: .1, .A, .ASM, .C, .CC, .CEL, .CFG, .CONF, .ELC, .ERR, .EX, .EXW, .H, .HS, .INC, .INFO, .JAVA, .JSON, .L, .LHS, .LPD, .LUA, .M, .MAN, Machine Description File, Markdown Documentation File, .MENU, .ML, .MPS, .OPTS, Java Properties File, Minecraft Properties File, .PY, .S, .TRI, .TXT, .UTF8

Price: Free

Website: GNU Emacs

D) Android

#1) File Viewer for Android

It is a free app for android where you can open and view files. It can display contents of over 150 file formats and you can view the hidden file details and metadata in the information panel of File Viewer. Its extract archives include 7-Zip, TGZ, Zip, Tar, Gzip, 7-Zip, and Bzip2.

Supported file types: .ada, .ahk, .as, bas, C/C++, .coffee, .cs, .css, .dart, .gradle, .groovy, .haml, .htaccess, .ini, .java, .js, .json, .kt, .less, .lisp, .lua, .m, .mk, .nim, .nsi, .pas, .php. .pl, .py, .ps1, .r, .rb, .sh, .sql, .xml, .vb, .tcl.

Price: Free

Conclusion

JSON is a minimal readable data format for structuring data. It was used mainly as an alternative to XML for transmitting data between a server and a web application. It is so easy to use as you can decode a whole site worth of JSON just by learning a few key principles.

JSON is an extremely popular and preferred data transition format. It is a text-based structure that makes it easy to read and deconstruct into individual data either by a machine or a user. It comes with the .json extension and you can create it by using any programming language.

Suggested reading =>> How to open a WebP file

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