How To Get Json Object From Restful Web Service

Recently I have to laissez passer JSON data to REST Service and did not have any simple Customer handy. But created very unproblematic Coffee program which read JSON information from file and sends it to Balance service.

Representational Land Transfer (Rest) has gained widespread acceptance across the Web every bit a simpler alternative to Soap- and Web Services Clarification Language (WSDL)-based Spider web services. Key prove of this shift in interface design is the adoption of Residue by mainstream Web 2.0 service providers—including Yahoo, Google, and Facebook—who have deprecated or passed on Lather and WSDL-based interfaces in favor of an easier-to-use, resource-oriented model to expose their services. In this article, Alex Rodriguez introduces you to the bones principles of REST.

Let's beginning coding this:

Create RESTFul Web Service
- Java file: CrunchifyRESTService.coffee
- web.xml file
Create RESTService Customer
1. CrunchifyRESTServiceClient.java file

Another must read: Leap MVC Instance/Tutorial: How-do-you-do World – Spring MVC 3.2.1

Step-1

In Eclipse => File => New => Dynamic Web Projection. Name it as "CrunchifyTutorials". Beneath tutorial also works with Tomcat eight.

Step-2 Create Deployment Descriptor File

If yous don't run across spider web.xml (deployment descriptor) under WebContent\WEB-INF\ and so follow these steps.

Open spider web.xml and supplant content with below contents:

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<? xml version="one.0" encoding="UTF-8" ?>

< web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns : xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi : schemaLocation="http://java.dominicus.com/xml/ns/javaee

http://java.lord's day.com/xml/ns/javaee/web-app_3_0.xsd"

version="three.0" >

< display-name > CrunchifyRESTJerseyExample </brandish-name >

< welcome-file-list >

< welcome-file > index . html </welcome-file >

< welcome-file > index . htm </welcome-file >

< welcome-file > index . jsp </welcome-file >

< welcome-file > default . html </welcome-file >

< welcome-file > default . htm </welcome-file >

< welcome-file > default . jsp </welcome-file >

</welcome-file-listing >

< servlet >

< servlet-name > Jersey Web Application </servlet-name >

< servlet-class > com . dominicus . jersey . spi . container . servlet . ServletContainer </servlet-class >

< load-on-startup > 1 </load-on-startup >

</servlet >

< servlet-mapping >

< servlet-name > Jersey Web Application </servlet-proper name >

< url-pattern >/api/*</url-design >

</servlet-mapping >

</web-app >

Footstep-3 Convert Project to Maven Project

Follow this tutorial: https://crunchify.com/how-to-convert-existing-java-projection-to-maven-in-eclipse/. Here is my pom.xml file.

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< projection xmlns="http://maven.apache.org/POM/4.0.0" xmlns : xsi="http://www.w3.org/2001/XMLSchema-instance"

xsi : schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-four.0.0.xsd" >

< modelVersion > 4.0.0 </modelVersion >

< groupId > CrunchifyTutorials </groupId >

< artifactId > CrunchifyTutorials </artifactId >

< version > 0.0.1-SNAPSHOT </version >

< packaging > state of war </packaging >

< build >

< sourceDirectory > src </sourceDirectory >

< plugins >

< plugin >

< artifactId > maven-compiler-plugin </artifactId >

< version > 3.1 </version >

< configuration >

< source > 1.viii </source >

< target > 1.8 </target >

</configuration >

</plugin >

< plugin >

< artifactId > maven-war-plugin </artifactId >

< version > 2.4 </version >

< configuration >

< warSourceDirectory > WebContent </warSourceDirectory >

< failOnMissingWebXml > false </failOnMissingWebXml >

</configuration >

</plugin >

</plugins >

</build >

< dependencies >

< dependency >

< groupId > asm </groupId >

< artifactId > asm-all </artifactId >

< version > three.iii.1 </version >

</dependency >

< dependency >

< groupId > com . lord's day . jersey </groupId >

< artifactId > jersey-bundle </artifactId >

< version > ane.14 </version >

</dependency >

< dependency >

< groupId > org . json </groupId >

< artifactId > json </artifactId >

< version > 20090211 </version >

</dependency >

</dependencies >

</project >

Footstep-4

Create RESTFul service: CrunchifyRESTService.java. Here we will create two services:

/api/crunchifyService – POST call – we volition use this with our test
/api/verify – Become telephone call – just to make sure service started successfully

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package com . crunchify . tutorials ;

/**

* @author Crunchify.com

import java . io . BufferedReader ;

import java . io . InputStream ;

import coffee . io . InputStreamReader ;

import javax . impress . attribute . standard . Media ;

import javax . ws . rs . Consumes ;

import javax . ws . rs . Get ;

import javax . ws . rs . POST ;

import javax . ws . rs . Path ;

import javax . ws . rs . Produces ;

import javax . ws . rs . core . MediaType ;

import javax . ws . rs . core . Response ;

@Path ( "/" )

public course CrunchifyRESTService {

@POST

@Path ( "/crunchifyService" )

@Consumes ( MediaType . APPLICATION_JSON )

public Response crunchifyREST ( InputStream incomingData ) {

StringBuilder crunchifyBuilder = new StringBuilder ( ) ;

endeavor {

BufferedReader in = new BufferedReader ( new InputStreamReader ( incomingData ) ) ;

String line = zilch ;

while ( ( line = in . readLine ( ) ) != null ) {

crunchifyBuilder . suspend ( line ) ;

}

} catch ( Exception e ) {

Arrangement . out . println ( "Error Parsing: - " ) ;

}

System . out . println ( "Information Received: " + crunchifyBuilder . toString ( ) ) ;

// return HTTP response 200 in instance of success

return Response . status ( 200 ) . entity ( crunchifyBuilder . toString ( ) ) . build ( ) ;

}

@Get

@Path ( "/verify" )

@Produces ( MediaType . TEXT_PLAIN )

public Response verifyRESTService ( InputStream incomingData ) {

String event = "CrunchifyRESTService Successfully started.." ;

// render HTTP response 200 in case of success

render Response . status ( 200 ) . entity ( effect ) . build ( ) ;

}

Step-v

Deploy project CrunchifyTutorials on Tomcat. Web projection should exist deployed without any exception.

Correct Click onServers tab in Eclipse
Click on Add together and Remove... Projection
Add together Project CrunchifyTutorials to right Configured: side.
Click on Publish
Click on Get-go

Step-6 Verify REST service

Residuum service should be attainable using this URL: http://127.0.0.i:8080/CrunchifyTutorials/api/verify

If you try to access http://127.0.0.1:8080/CrunchifyTutorials/api/crunchifyService then you lot will see mistake code 405 - Method not immune – which is valid response. Every bit you lot tin can see it's POST phone call and should await some data with the request.

Permit's movement on.

Stride-7

Re-create beneath JSON content and put it under C:\\CrunchifyJSON.txt file for windows or /Users/<username>/Documents/CrunchifyJSON.txt file if Macbook.

{

"tutorials" : {

"id" : "Crunchify" ,

"topic" : "REST Service" ,

"description" : "This is REST Service Case by Crunchify."

}

Footstep-8

Create REST Call Client: CrunchifyRESTServiceClient.java.

Please modify path to CrunchifyJSON.txt in below plan.

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bundle com . crunchify . tutorials ;

import java . io . BufferedReader ;

import java . io . FileInputStream ;

import coffee . io . InputStream ;

import java . io . InputStreamReader ;

import java . io . OutputStreamWriter ;

import java . net . URL ;

import java . net . URLConnection ;

import org . json . JSONObject ;

/**

* @author Crunchify.com

public class CrunchifyRESTServiceClient {

public static void main ( String [ ] args ) {

Cord string = "" ;

try {

// Step1: Let'due south 1st read file from fileSystem

// Change CrunchifyJSON.txt path here

InputStream crunchifyInputStream = new FileInputStream ( "/Users/<username>/Documents/CrunchifyJSON.txt" ) ;

InputStreamReader crunchifyReader = new InputStreamReader ( crunchifyInputStream ) ;

BufferedReader br = new BufferedReader ( crunchifyReader ) ;

String line ;

while ( ( line = br . readLine ( ) ) != null ) {

string += line + "\n" ;

}

JSONObject jsonObject = new JSONObject ( string ) ;

Organisation . out . println ( jsonObject ) ;

// Step2: Now laissez passer JSON File Information to REST Service

attempt {

URL url = new URL ( "http://localhost:8080/CrunchifyTutorials/api/crunchifyService" ) ;

URLConnection connection = url . openConnection ( ) ;

connection . setDoOutput ( true ) ;

connexion . setRequestProperty ( "Content-Blazon" , "application/json" ) ;

connection . setConnectTimeout ( 5000 ) ;

connectedness . setReadTimeout ( 5000 ) ;

OutputStreamWriter out = new OutputStreamWriter ( connectedness . getOutputStream ( ) ) ;

out . write ( jsonObject . toString ( ) ) ;

out . close ( ) ;

BufferedReader in = new BufferedReader ( new InputStreamReader ( connectedness . getInputStream ( ) ) ) ;

while ( in . readLine ( ) != zippo ) {

}

System . out . println ( "\nCrunchify Residue Service Invoked Successfully.." ) ;

in . close ( ) ;

} catch ( Exception e ) {

System . out . println ( "\nError while calling Crunchify REST Service" ) ;

System . out . println ( due east ) ;

}

br . close ( ) ;

} grab ( Exception e ) {

e . printStackTrace ( ) ;

}

Step-9

Now let's run Client Plan by right click on CrunchifyRESTServiceClient.java and y'all should encounter below two outputs

i) in Tomcat Console

two) in Local Customer Console

I'm an Engineer past profession, Blogger by passion & Founder of Crunchify, LLC, the largest free blogging & technical resource site for beginners. Dear SEO, SaaS, #webperf, WordPress, Java. With over 16 millions+ pageviews/month, Crunchify has changed the life of over thousands of individual around the world teaching Java & Web Tech for FREE.