POC on Hateoas

.gitignore

+HELP.md
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**
+!**/src/test/**
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+
+### VS Code ###
+.vscode/

.mvn/wrapper/MavenWrapperDownloader.java

+/*
+ * Copyright 2007-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import java.net.*;
+import java.io.*;
+import java.nio.channels.*;
+import java.util.Properties;
+
+public class MavenWrapperDownloader {
+
+    private static final String WRAPPER_VERSION = "0.5.6";
+    /**
+     * Default URL to download the maven-wrapper.jar from, if no 'downloadUrl' is provided.
+     */
+    private static final String DEFAULT_DOWNLOAD_URL = "https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/"
+        + WRAPPER_VERSION + "/maven-wrapper-" + WRAPPER_VERSION + ".jar";
+
+    /**
+     * Path to the maven-wrapper.properties file, which might contain a downloadUrl property to
+     * use instead of the default one.
+     */
+    private static final String MAVEN_WRAPPER_PROPERTIES_PATH =
+            ".mvn/wrapper/maven-wrapper.properties";
+
+    /**
+     * Path where the maven-wrapper.jar will be saved to.
+     */
+    private static final String MAVEN_WRAPPER_JAR_PATH =
+            ".mvn/wrapper/maven-wrapper.jar";
+
+    /**
+     * Name of the property which should be used to override the default download url for the wrapper.
+     */
+    private static final String PROPERTY_NAME_WRAPPER_URL = "wrapperUrl";
+
+    public static void main(String args[]) {
+        System.out.println("- Downloader started");
+        File baseDirectory = new File(args[0]);
+        System.out.println("- Using base directory: " + baseDirectory.getAbsolutePath());
+
+        // If the maven-wrapper.properties exists, read it and check if it contains a custom
+        // wrapperUrl parameter.
+        File mavenWrapperPropertyFile = new File(baseDirectory, MAVEN_WRAPPER_PROPERTIES_PATH);
+        String url = DEFAULT_DOWNLOAD_URL;
+        if(mavenWrapperPropertyFile.exists()) {
+            FileInputStream mavenWrapperPropertyFileInputStream = null;
+            try {
+                mavenWrapperPropertyFileInputStream = new FileInputStream(mavenWrapperPropertyFile);
+                Properties mavenWrapperProperties = new Properties();
+                mavenWrapperProperties.load(mavenWrapperPropertyFileInputStream);
+                url = mavenWrapperProperties.getProperty(PROPERTY_NAME_WRAPPER_URL, url);
+            } catch (IOException e) {
+                System.out.println("- ERROR loading '" + MAVEN_WRAPPER_PROPERTIES_PATH + "'");
+            } finally {
+                try {
+                    if(mavenWrapperPropertyFileInputStream != null) {
+                        mavenWrapperPropertyFileInputStream.close();
+                    }
+                } catch (IOException e) {
+                    // Ignore ...
+                }
+            }
+        }
+        System.out.println("- Downloading from: " + url);
+
+        File outputFile = new File(baseDirectory.getAbsolutePath(), MAVEN_WRAPPER_JAR_PATH);
+        if(!outputFile.getParentFile().exists()) {
+            if(!outputFile.getParentFile().mkdirs()) {
+                System.out.println(
+                        "- ERROR creating output directory '" + outputFile.getParentFile().getAbsolutePath() + "'");
+            }
+        }
+        System.out.println("- Downloading to: " + outputFile.getAbsolutePath());
+        try {
+            downloadFileFromURL(url, outputFile);
+            System.out.println("Done");
+            System.exit(0);
+        } catch (Throwable e) {
+            System.out.println("- Error downloading");
+            e.printStackTrace();
+            System.exit(1);
+        }
+    }
+
+    private static void downloadFileFromURL(String urlString, File destination) throws Exception {
+        if (System.getenv("MVNW_USERNAME") != null && System.getenv("MVNW_PASSWORD") != null) {
+            String username = System.getenv("MVNW_USERNAME");
+            char[] password = System.getenv("MVNW_PASSWORD").toCharArray();
+            Authenticator.setDefault(new Authenticator() {
+                @Override
+                protected PasswordAuthentication getPasswordAuthentication() {
+                    return new PasswordAuthentication(username, password);
+                }
+            });
+        }
+        URL website = new URL(urlString);
+        ReadableByteChannel rbc;
+        rbc = Channels.newChannel(website.openStream());
+        FileOutputStream fos = new FileOutputStream(destination);
+        fos.getChannel().transferFrom(rbc, 0, Long.MAX_VALUE);
+        fos.close();
+        rbc.close();
+    }
+
+}

.mvn/wrapper/maven-wrapper.properties

+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.6.3/apache-maven-3.6.3-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar

mvnw.cmd

+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_pre.bat" call "%HOME%\mavenrc_pre.bat"
+if exist "%HOME%\mavenrc_pre.cmd" call "%HOME%\mavenrc_pre.cmd"
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+
+FOR /F "tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/io/takari/maven-wrapper/0.5.6/maven-wrapper-0.5.6.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% %JVM_CONFIG_MAVEN_PROPS% %MAVEN_OPTS% %MAVEN_DEBUG_OPTS% -classpath %WRAPPER_JAR% "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%HOME%\mavenrc_post.bat" call "%HOME%\mavenrc_post.bat"
+if exist "%HOME%\mavenrc_post.cmd" call "%HOME%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%" == "on" pause
+
+if "%MAVEN_TERMINATE_CMD%" == "on" exit %ERROR_CODE%
+
+exit /B %ERROR_CODE%

pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project 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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-parent</artifactId>
+		<version>2.2.4.RELEASE</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>com.nisum</groupId>
+	<artifactId>hateoas</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>hateoas</name>
+	<description>Demo project for Spring Boot</description>
+
+	<properties>
+		<java.version>1.8</java.version>
+		<mockito-core.version>1.10.19</mockito-core.version>
+		<powermock-module-junit4.version>2.0.4</powermock-module-junit4.version>
+		<powermock-api-mockito.version>1.7.4</powermock-api-mockito.version>
+	</properties>
+
+	<dependencies>
+		<!-- https://mvnrepository.com/artifact/org.springframework.hateoas/spring-hateoas -->
+		<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-hateoas -->
+	<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-hateoas</artifactId>
+		</dependency>
+		<!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpclient -->
+		<dependency>
+			<groupId>org.apache.httpcomponents</groupId>
+			<artifactId>httpclient</artifactId>
+			<version>4.5.8</version>
+		</dependency>
+
+
+
+		<!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-data-cassandra -->
+
+		<dependency>
+			<groupId>org.springframework.hateoas</groupId>
+			<artifactId>spring-hateoas</artifactId>
+			<version>0.24.0.RELEASE</version>
+			<scope>compile</scope>
+		</dependency>
+		<!-- https://mvnrepository.com/artifact/org.slf4j/slf4j-api -->
+		<dependency>
+			<groupId>org.slf4j</groupId>
+			<artifactId>slf4j-api</artifactId>
+			<version>1.7.26</version>
+		</dependency>
+
+		<!-- https://mvnrepository.com/artifact/javax.ws.rs/javax.ws.rs-api -->
+		<dependency>
+			<groupId>javax.ws.rs</groupId>
+			<artifactId>javax.ws.rs-api</artifactId>
+			<version>2.1</version>
+		</dependency>
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-web</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>org.projectlombok</groupId>
+			<artifactId>lombok</artifactId>
+			<optional>true</optional>
+		</dependency>
+		<!-- https://mvnrepository.com/artifact/com.googlecode.json-simple/json-simple -->
+		<dependency>
+			<groupId>com.googlecode.json-simple</groupId>
+			<artifactId>json-simple</artifactId>
+			<version>1.1</version>
+		</dependency>
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+			<exclusions>
+				<exclusion>
+					<groupId>org.junit.vintage</groupId>
+					<artifactId>junit-vintage-engine</artifactId>
+				</exclusion>
+				<exclusion>
+					<groupId>org.mockito</groupId>
+					<artifactId>mockito-core</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+		<dependency>
+			<groupId>org.mockito</groupId>
+			<artifactId>mockito-core</artifactId>
+			<version>${mockito-core.version}</version>
+			<scope>test</scope>
+			<exclusions>
+				<exclusion>
+					<groupId>org.objenesis</groupId>
+					<artifactId>objenesis</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+		<dependency>
+			<groupId>org.powermock</groupId>
+			<artifactId>powermock-module-junit4</artifactId>
+			<version>${powermock-module-junit4.version}</version>
+			<scope>test</scope>
+			<exclusions>
+				<exclusion>
+					<groupId>org.powermock</groupId>
+					<artifactId>powermock-core</artifactId>
+				</exclusion>
+				<exclusion>
+					<groupId>org.powermock</groupId>
+					<artifactId>powermock-reflect</artifactId>
+				</exclusion>
+				<exclusion>
+					<groupId>org.objenesis</groupId>
+					<artifactId>objenesis</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+		<dependency>
+			<groupId>org.powermock</groupId>
+			<artifactId>powermock-api-mockito</artifactId>
+			<version>${powermock-api-mockito.version}</version>
+			<scope>test</scope>
+			<exclusions>
+				<exclusion>
+					<groupId>org.mockito</groupId>
+					<artifactId>mockito-core</artifactId>
+				</exclusion>
+			</exclusions>
+		</dependency>
+	</dependencies>
+
+<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+
+</project>

src/main/java/com/nisum/Clients/HttpClient.java

+package com.nisum.Clients;
+
+import com.nisum.HateoasApplication;
+import com.nisum.constants.Constants;
+import org.apache.http.HttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.DefaultHttpClient;
+import org.json.simple.JSONObject;
+import org.json.simple.parser.JSONParser;
+import org.json.simple.parser.ParseException;
+import org.springframework.beans.factory.annotation.Autowired;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.URL;
+
+public class HttpClient {
+
+    @Autowired
+    HateoasApplication hateoasApplication;
+
+
+
+    //Using HTTP (Method 2)
+    public void getUsingHttpClient() throws IOException, ParseException {
+
+        try {
+            DefaultHttpClient httpClient = new DefaultHttpClient();
+            HttpGet getRequest = new HttpGet(Constants.URL_EMPLOYEES);
+            getRequest.addHeader("accept", "application/json");
+            HttpResponse response = httpClient.execute(getRequest);
+
+            if (response.getStatusLine().getStatusCode() != 200) {
+                throw new RuntimeException("Failed : HTTP error code : "
+                        + response.getStatusLine().getStatusCode());
+            } else {
+
+                int i = 0;
+                JSONObject obj = null;
+                do {
+                    if (i == 0) {
+                        System.out.println(response);
+                        obj = getJsonObjectHttp(response, 0);
+                        hateoasApplication.saveInFile(obj, i);
+                    } else {
+                        URL url = new URL(obj.get("next").toString());
+                        HttpGet getRequestNew = new HttpGet(url.toString());
+                        getRequestNew.addHeader("accept", "application/json");
+                        HttpResponse responseNew = httpClient.execute(getRequestNew);
+                        JSONObject objnew = getJsonObjectHttp(responseNew, i);
+                        hateoasApplication.saveInFile(objnew, i);
+                        obj = objnew;
+                    }
+                    i++;
+
+                } while (i <= Constants.no_of_pages - 1);
+                httpClient.getConnectionManager().shutdown();
+            }
+        }
+        catch(RuntimeException e){
+            e.getStackTrace();
+        }
+    }
+
+
+
+    //Method to get a json object from the content of a get call when using httpClient
+    public JSONObject getJsonObjectHttp(HttpResponse response, int i) throws IOException, ParseException {
+        BufferedReader br = new BufferedReader(new InputStreamReader((response.getEntity().getContent())));
+        String output;
+        output=br.readLine();
+        JSONParser parser = new JSONParser();
+        JSONObject obj = (JSONObject) parser.parse(output);
+        return obj;
+    }
+
+
+}

src/main/java/com/nisum/Clients/RestTemplateClient.java

+package com.nisum.Clients;
+
+import com.nisum.HateoasApplication;
+import com.nisum.constants.Constants;
+import org.json.simple.JSONObject;
+import org.json.simple.parser.JSONParser;
+import org.json.simple.parser.ParseException;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.web.client.RestTemplate;
+
+import java.io.BufferedWriter;
+import java.io.FileWriter;
+import java.io.IOException;
+
+
+
+public class RestTemplateClient {
+
+    @Autowired
+    HateoasApplication hateoasApplication;
+
+
+    @Bean
+    public RestTemplate getRestTemplate() {
+        return new RestTemplate();
+    }
+
+    //using Spring Rest Template(Method 1)
+    public void getUsingRestTemplate()  {
+        try {
+            int i = 0;
+            JSONObject obj = null;
+            do {
+                if (i == 0) {
+                    obj = getJSONObject(Constants.URL_EMPLOYEES);
+                    hateoasApplication.saveInFile(obj, 0);
+                } else {
+                    JSONObject objnew = getJSONObject(obj.get("next").toString());
+                    hateoasApplication.saveInFile(objnew, i);
+                    obj = objnew;
+                }
+                i++;
+            } while (i <= Constants.no_of_pages - 1);
+        }
+        catch(ParseException e){
+            e.getStackTrace();
+        }
+        catch(IOException ex){
+            ex.getStackTrace();
+        }
+    }
+
+    //Method to get a json object from the content of a get call when using rest template
+    public JSONObject getJSONObject(String URL) throws ParseException {
+        String result = getRestTemplate().getForObject(URL, String.class);
+        JSONParser parser = new JSONParser();
+        JSONObject obj = (JSONObject) parser.parse(result);
+        return obj;
+    }
+
+
+}

src/main/java/com/nisum/HateoasApplication.java

+package com.nisum;
+
+
+import com.nisum.Clients.HttpClient;
+import com.nisum.Clients.RestTemplateClient;
+import com.nisum.constants.Constants;
+
+
+import org.apache.http.HttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.DefaultHttpClient;
+import org.json.simple.JSONObject;
+import org.json.simple.parser.JSONParser;
+import org.json.simple.parser.ParseException;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringApplication;
+
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import org.springframework.web.client.RestTemplate;
+
+import java.io.*;
+import java.net.URL;
+
+@SpringBootApplication
+public class HateoasApplication {
+
+	@Autowired
+	RestTemplateClient restTemplateClient;
+
+	@Autowired
+	HttpClient httpClient;
+
+
+	//Get Calls using 2 clients:Rest client and HttpClient
+	public static void main(String[] args) {
+		try {
+			SpringApplication.run(HateoasApplication.class, args);
+			HateoasApplication ha = new HateoasApplication();
+			restTemplateClient.getUsingRestTemplate();
+			hhttpClient.getUsingHttpClient();
+		} catch (ParseException e) {
+			e.getStackTrace();
+		} catch (IOException ex) {
+			ex.getStackTrace();
+		}
+		catch(Exception et){
+			et.getStackTrace();
+		}
+	}
+
+	//Method to save the json object to different files with data of each page in separate file
+	public void saveInFile(JSONObject jsonObject, int i) throws IOException {
+		BufferedWriter writer = new BufferedWriter(new FileWriter("D:\\Backup Folder\\hateoas" + (i + 1) + ".json"));
+		writer.newLine();
+		writer.write(jsonObject.toString());
+		writer.close();
+	}
+
+
+
+
+
+
+
+}
+
+
+
+

src/main/java/com/nisum/constants/Constants.java

+package com.nisum.constants;
+
+public class Constants {
+
+    public static final  int page_size=5;
+    public static final  int no_of_pages=4;
+    public static final String URL_EMPLOYEES = "http://localhost:8080/start/users/0";
+}

src/main/java/com/nisum/controller/UserController.java

+package com.nisum.controller;
+
+
+import com.nisum.model.FirstResponse;
+import com.nisum.model.User;
+import com.nisum.model.Users;
+import com.nisum.service.UserServiceImpl;
+import lombok.extern.slf4j.Slf4j;
+import org.apache.tomcat.util.file.ConfigurationSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.hateoas.Resource;
+import org.springframework.hateoas.mvc.ControllerLinkBuilder;
+import org.springframework.util.StreamUtils;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.client.RestTemplate;
+
+
+import javax.ws.rs.HttpMethod;
+import javax.ws.rs.QueryParam;
+import java.io.File;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+
+import static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;
+
+@Slf4j
+@RestController
+@RequestMapping(value = "/start")
+public class UserController {
+    public int startOffset=0;
+
+    @Autowired
+    UserServiceImpl userServiceImpl;
+
+    @Autowired
+    private RestTemplate restTemplate;
+
+    @GetMapping("/users/firstpage")
+    public Resource<FirstResponse>  getFirstPage() {
+        FirstResponse fr=new FirstResponse();
+        log.info("Getting all Users...");
+        Resource<FirstResponse> resource=new Resource<>(fr);
+        ControllerLinkBuilder linkTo=linkTo(ControllerLinkBuilder.methodOn(this.getClass()).getAllUsers(0));
+        resource.add(linkTo.withRel("all_users"));
+        return resource;
+    }
+
+    @GetMapping("/users/{startOffset}")
+    public Users getAllUsers(@PathVariable("startOffset") int startOffset) {
+        return userServiceImpl.getAllUsers(startOffset);
+    }
+
+
+}

src/main/java/com/nisum/model/FirstResponse.java

+package com.nisum.model;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class FirstResponse {
+
+    private int no_of_pages=4;
+
+}

src/main/java/com/nisum/model/User.java

+package com.nisum.model;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class User {
+
+
+    private int id;
+    private String name;
+    private String place;
+
+
+
+}

src/main/java/com/nisum/model/Users.java

+package com.nisum.model;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import org.springframework.hateoas.mvc.ControllerLinkBuilder;
+
+import java.net.URI;
+import java.util.List;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class Users {
+   private int page_no;
+   private  List<User> users;
+   private URI next;
+   private URI previous;
+
+}

src/main/java/com/nisum/service/UserService.java

+package com.nisum.service;
+
+import com.nisum.model.User;
+import com.nisum.model.Users;
+import org.springframework.hateoas.Resource;
+
+import java.util.List;
+import java.util.Map;
+
+public interface UserService {
+
+    List<User> getList();
+    Users getAllUsers(int startOffset);
+
+}

src/main/java/com/nisum/service/UserServiceImpl.java

+package com.nisum.service;
+
+import com.nisum.constants.Constants;
+
+import com.nisum.controller.UserController;
+import com.nisum.model.User;
+
+
+import com.nisum.model.Users;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.hateoas.Resource;
+import org.springframework.hateoas.mvc.ControllerLinkBuilder;
+import org.springframework.stereotype.Service;
+
+import java.util.ArrayList;
+
+import java.util.List;
+
+import static com.nisum.constants.Constants.page_size;
+import static org.springframework.hateoas.mvc.ControllerLinkBuilder.linkTo;
+
+//Server End Code
+
+@Service
+public class UserServiceImpl implements UserService {
+
+    @Autowired
+    UserController userController;
+
+    private User buildUser(Integer id,  String name, String place){
+        User user=new User(id,name,place);
+        return user;
+    }
+
+
+    public List<User> getList(){
+        List<User> UserList=new ArrayList<>();
+        UserList.add(buildUser(1,"Divisha","Udaipur"));
+        UserList.add(buildUser(2,"Ashwarya","Hyderabad"));
+        UserList.add(buildUser(3,"Vinit","Delhi"));
+        UserList.add(buildUser(4,"Deepika","Jaipur"));
+        UserList.add(buildUser(5,"Priyanka","Mumbai"));
+        UserList.add(buildUser(6,"Rahul","Pune"));
+        UserList.add(buildUser(7,"Dev","Bangalore"));
+        UserList.add(buildUser(8,"Kapil","Kochi"));
+        UserList.add(buildUser(9,"Sachin","Bhopal"));
+        UserList.add(buildUser(10,"Yuvraj","Indore"));
+        UserList.add(buildUser(11,"Virat","Ahmedabad"));
+        UserList.add(buildUser(12,"Rohit","Kozikhode"));
+        UserList.add(buildUser(13,"Virendra","Rohtak"));
+        UserList.add(buildUser(14,"Mithali","Ranchi"));
+        UserList.add(buildUser(15,"Shafali","Nagpur"));
+        UserList.add(buildUser(16,"Harmanpreet","Vishakhapatnam"));
+        UserList.add(buildUser(17,"Veda","Sambalpur"));
+        UserList.add(buildUser(18,"Smriti","Jamshedpur"));
+        UserList.add(buildUser(19,"Sania","Goa"));
+        UserList.add(buildUser(20,"Usha","Noida"));
+        return UserList;
+
+    }
+
+
+    @Override
+    public  Users getAllUsers(int startOffset) {
+        int i ;
+        for (i = 0; i <= getList().size(); i = i + page_size) {
+        List<User> subList = getList().subList(startOffset, startOffset + page_size);
+        Users userList = new Users();
+        userList.setUsers(subList);
+        userList.setPage_no((startOffset/page_size)+1);
+        Resource<Users> resource = new Resource<Users>(userList);
+        ControllerLinkBuilder next = linkTo(ControllerLinkBuilder.methodOn(UserController.class).getAllUsers(startOffset + page_size));
+        ControllerLinkBuilder previous = linkTo(ControllerLinkBuilder.methodOn(UserController.class).getAllUsers(startOffset-page_size ));
+
+        if(startOffset==getList().size()-page_size) {
+                userList.setNext(null);
+            }
+        else {
+            userList.setNext(next.toUri());
+        }
+        if (startOffset == 0){
+            userList.setPrevious(null);
+        }
+        else
+        {
+            userList.setPrevious(previous.toUri());
+        }
+
+        resource.add(next.withRel("all_users"));
+
+        return userList;
+        }
+        return null;
+        }
+
+
+    }
+

src/main/resources/application.yml

+spring:
+  data:
+    cassandra:
+      keyspace-name: userspace # We need to create keyspace manually from cassandra console
+      contact-points:
+        - 127.0.0.1                # IP Address where Cassandra is running
+      port: 9042
+      schema-action: create_if_not_exists
+
+server:
+  port: 8080

src/test/java/com/nisum/HateoasApplicationTests.java

+package com.nisum;
+
+import org.apache.http.HttpResponse;
+import org.apache.http.StatusLine;
+import org.apache.http.client.HttpClient;
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.DefaultHttpClient;
+import org.json.simple.JSONObject;
+import org.json.simple.parser.JSONParser;
+import org.json.simple.parser.ParseException;
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+import org.powermock.core.classloader.annotations.PowerMockIgnore;
+import org.powermock.core.classloader.annotations.PrepareForTest;
+import org.powermock.modules.junit4.PowerMockRunner;
+import java.io.IOException;
+import static org.mockito.Mockito.*;
+
+
+@RunWith(PowerMockRunner.class)
+@PowerMockIgnore("jdk.internal.reflect.*")
+@PrepareForTest({HateoasApplication.class,JSONObject.class})
+public class HateoasApplicationTests {
+
+	@InjectMocks
+	HateoasApplication hateoasApplication;
+
+	@Mock
+	public JSONParser parser;
+
+	@Before()
+	public void setUp() throws Exception {
+		MockitoAnnotations.initMocks(this);
+		JSONObject mock = Mockito.mock(JSONObject.class);
+		when(hateoasApplication.getRestTemplate().getForObject(anyString(),String.class)).thenReturn(anyString());
+		when(parser.parse(anyString())).thenReturn(mock);
+		when(hateoasApplication.getJSONObject(anyString())).thenReturn(mock);
+	}
+
+	@Test
+	public void getUsingRestTemplateTest() throws IOException, ParseException {
+		hateoasApplication.getUsingRestTemplate();
+	}
+
+	@Test
+	public void getUsingHttpClientTest() throws IOException, ParseException {
+		DefaultHttpClient httpClient = mock(DefaultHttpClient.class);
+		HttpGet getRequest = mock(HttpGet.class);
+		HttpResponse httpResponse = mock(HttpResponse.class);
+		StatusLine statusLine = mock(StatusLine.class);
+		when(statusLine.getStatusCode()).thenReturn(200);
+		when(httpResponse.getStatusLine()).thenReturn(statusLine);
+		when(httpClient.execute(getRequest)).thenReturn((CloseableHttpResponse) httpResponse);
+		Assert.assertEquals(statusLine.getStatusCode(),200);
+		hateoasApplication.getUsingHttpClient();
+	}
+
+	@Test
+	public void getUsingHttpClientExceptionTest() throws IOException, ParseException {
+		HttpClient httpClient = mock(HttpClient.class);
+		HttpGet httpGet = mock(HttpGet.class);
+		StatusLine statusLine = mock(StatusLine.class);
+		when(httpClient.execute(httpGet)).thenThrow(RuntimeException.class);
+		Assert.assertEquals(statusLine.getStatusCode(),0);
+		hateoasApplication.getUsingHttpClient();
+	}
+
+	@Test
+	public void getJSONObjectTest() throws ParseException, IOException {
+		verify(hateoasApplication.getJSONObject(anyString()), times(4));
+	}
+
+	@Test
+	public void getJSONObjectHttpTest() throws ParseException, IOException {
+		verify(hateoasApplication.getJsonObjectHttp(any(HttpResponse.class),anyInt()), times(4));
+	}
+
+}