<< Chapter < Page Chapter >> Page >

Display the JSON string

The code in Listing 2 displays the raw JSON string followed by a blank line.

Listing 2 . Display the JSON string. System.out.println("json string: " + jsonMap); System.out.println();//blank line

This code produces the screen output shown by the screen shot in Figure 1 .

Figure 1. Screen shot of raw JSON string. json string: {"game":[{"cards":["2-club","3-heart","4-diamond","5-spade"],"name":"Tom"},{"cards":["4-heart","5-heart","6-club","7-diamond"],"name":"Joe"}]}

Note that the line break in Figure 1 was inserted by the operating system while displaying the string in the command-line window. The line break does notexist in the data in the file.

Access the game array

Listing 3 calls the get method inherited from the HashMap class to get the game array into an object of type JSONArray , which is a subclass of the ArrayList class.

Listing 3 . Access the game array. JSONArray gameArrayList = (JSONArray)jsonMap.get("game");

Get information about the first player

Recall that a JSONArray object is an ordered list as a subclass of the ArrayList class. The get method inherited from the ArrayList class can be used to access elements in the list on the basis of a zero-based index.At this point, information about the first player is stored in the list as an object of type JSONObject . (It is actually stored as type Object and must be downcast to type JSONObject in order to do much with it.)

Listing 4 begins by accessing the element at an index value of zero, which is the object containing information about the first player.

Listing 4 . Get information about the first player. JSONObject firstPlayerMap = (JSONObject)gameArrayList.get(0); System.out.println("First Player's Name: " +firstPlayerMap.get("name"));

Then Listing 4 uses the get method inherited from the HashMap class to get and display the value associated with the key "name". This produces the screen output shown in Figure 2 .

Figure 2. Display first player's name. First Player's Name: Tom

Display first player's cards

Listing 5 begins by using the get method of the HashMap class to access the JSONArray object that is the value for the key "cards".

Listing 5 . Display first player's cards. JSONArray firstPlayerCardsList = (JSONArray)firstPlayerMap.get("cards");System.out.println("First Player's cards"); Iterator<String>iterator = firstPlayerCardsList.iterator(); while (iterator.hasNext()) {System.out.println(iterator.next()); }//end while loop

Then Listing 5 uses an iterator to iterate through the JSONArray object and to display each of the cards in the array, (which is actually a list at this point) . This code produces the output shown in Figure 3 .

Figure 3. The first player's cards. First Player's cards 2-club3-heart 4-diamond5-spade

Get and display information about the second player

Listing 6 uses similar code to get and display information about the second player.

Listing 6 . Get and display information about the second player. System.out.println(); JSONObject secondPlayerMap = (JSONObject)gameArrayList.get(1);System.out.println("Second Player's Name: " + secondPlayerMap.get("name"));JSONArray secondPlayerCardsList =(JSONArray)secondPlayerMap.get("cards"); System.out.println("Second Player's cards");iterator = secondPlayerCardsList.iterator(); while (iterator.hasNext()) {System.out.println(iterator.next()); }//end while loop}//end main }//end class Code

Questions & Answers

what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
Privacy Information Security Software Version 1.1a
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get the best Algebra and trigonometry course in your pocket!

Source:  OpenStax, Object-oriented programming (oop) with java. OpenStax CNX. Jun 29, 2016 Download for free at https://legacy.cnx.org/content/col11441/1.201
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Object-oriented programming (oop) with java' conversation and receive update notifications?