Sample REST Applications
This topic provides examples that illustrate how multiple clients, both REST and native, can access the same VMware Tanzu GemFire region data.
Note: You must set PDX read-serialized to true when starting the cache server to achieve interoperability between different clients. See Setup and Configuration for instructions on starting up REST-enabled cache servers.
The following examples demonstrate the following:
-
A Java REST client creates a Person object on key 1. This client references the following supporting examples (also provided):
- Tanzu GemFire cache client
- REST client utility
- Date Time utility
- Person class
- Gender class
-
A Ruby REST client also gets data for key 1 and updates it.
- A Python REST Client demonstrates the creation and modification of objects. Note: An additional Python REST client reference application is available here: https://github.com/gemfire/py-gemfire-rest.
The following Java examples assume a project directory structure similar to the following:
#1. REST Java Client (RestClientApp.java)
package org.apache.geode.restclient;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpEntity;
import org.springframework.http.ResponseEntity;
import org.springframework.web.client.HttpClientErrorException;
import org.springframework.web.client.HttpServerErrorException;
import org.apache.geode.util.RestClientUtils;
import java.util.ArrayList;
import java.util.List;
@SuppressWarnings( "unused")
public class RestClientApp {
private static final String PEOPLE_REGION = "/People";
private static final String PERSON1_AS_JSON = "{"
+ "\"@type\ ": \"org.apache.geode.domain.Person\ "," + "\"id\ ": 1,"
+ " \"firstName\ ": \"Jane\ "," + " \"middleName\ ": \"H\ ","
+ " \"lastName\ ": \"Doe1\ "," + " \"birthDate\ ": \"04/12/1983\ ","
+ "\"gender\ ": \"MALE\ "" + "}";
public static void main( final String... args) throws Exception {
doCreate(PEOPLE_REGION, "1");
System.out.println( "Programme has run successfully...!");
}
private static HttpHeaders setAcceptAndContentTypeHeaders(){
List<MediaType> acceptableMediaTypes = new ArrayList<>();
acceptableMediaTypes.add(MediaType.APPLICATION_JSON);
HttpHeaders headers = new HttpHeaders();
headers.setAccept(acceptableMediaTypes);
headers.setContentType(MediaType.APPLICATION_JSON);
return headers;
}
private static void doCreate( final String regionNamePath, final String key) {
HttpHeaders headers = setAcceptAndContentTypeHeaders();
HttpEntity< String> entity = new HttpEntity< String>(PERSON1_AS_JSON, headers);
try {
ResponseEntity< String> result = RestClientUtils.getRestTemplate().exchange(
"http://localhost:8080/gemfire-api/v1/People?key=1" , HttpMethod.POST,
entity, String.class);
System.out.println( "STATUS_CODE = " + result.getStatusCode().value());
System.out.println( "HAS_BODY = " + result.hasBody());
System.out.println( "LOCATION_HEADER = " + result.getHeaders().getLocation().toString());
} catch (HttpClientErrorException e) {
System.out.println( "Http Client encountered error, msg:: " + e.getMessage());
} catch(HttpServerErrorException se) {
System.out.println( "Server encountered error, msg::" + se.getMessage());
} catch (Exception e) {
System.out.println( "Unexpected ERROR...!!");
}
}
}
#1a. Tanzu GemFire Cache Java Client (MyJavaClient.java)
package org.apache.geode.javaclient;
import java.util.Calendar;
import java.util.HashMap;
import java.util.Map;
import org.apache.geode.cache.Region;
import org.apache.geode.cache.client.ClientCache;
import org.apache.geode.cache.client.ClientCacheFactory;
import org.apache.geode.cache.client.ClientRegionFactory;
import org.apache.geode.cache.client.ClientRegionShortcut;
import org.apache.geode.domain.Gender;
import org.apache.geode.domain.Person;
import org.apache.geode.pdx.PdxInstance;
import org.apache.geode.util.DateTimeUtils;
public class MyJavaClient {
public static void main( String[] args) {
ClientCacheFactory cf = new ClientCacheFactory().addPoolServer( "localhost", 40405);
ClientCache cache = cf.setPdxReadSerialized( true).create();
ClientRegionFactory rf = cache.createClientRegionFactory(ClientRegionShortcut.PROXY);
Region region = rf.create( "People");
//Get data on key "1" , update it and put it again in cache
Person actualObj = null;
Object obj = region.get( "1");
if(obj instanceof PdxInstance){
System.out.println( "Obj is PdxInstance");
PdxInstance pi = (PdxInstance)obj;
Object obj2 = pi.getObject();
if(obj2 instanceof Person){
actualObj = (Person)obj2;
System.out.println( "Received Person :" + actualObj.toString());
} else {
System.out.println( "Error: obj2 is expected to be of type Person");
}
} else {
System.out.println( "Error: obj is expected to be of type PdxInstance");
}
//update the received object and put it in cache
if(actualObj != null){
actualObj.setFirstName( "Jane_updated");
actualObj.setLastName( "Doe_updated");
region.put( "1", actualObj);
}
//Add/putAll set of person objects
final Person person2 = new Person(102L, "Sachin", "Ramesh", "Tendulkar", DateTimeUtils.createDate(1975, Calendar.DECEMBER, 14), Gender.MALE);
final Person person3 = new Person(103L, "Saurabh", "Baburav", "Ganguly", DateTimeUtils.createDate(1972, Calendar.AUGUST, 29), Gender.MALE);
final Person person4 = new Person(104L, "Rahul", "subrymanyam", "Dravid", DateTimeUtils.createDate(1979, Calendar.MARCH, 17), Gender.MALE);
final Person person5 = new Person(105L, "Jhulan", "Chidambaram", "Goswami", DateTimeUtils.createDate(1983, Calendar.NOVEMBER, 25), Gender.FEMALE);
final Person person6 = new Person(101L, "Rahul", "Rajiv", "Gndhi", DateTimeUtils.createDate(1970, Calendar.MAY, 14), Gender.MALE);
final Person person7 = new Person(102L, "Narendra", "Damodar", "Modi", DateTimeUtils.createDate(1945, Calendar.DECEMBER, 24), Gender.MALE);
final Person person8 = new Person(103L, "Atal", "Bihari", "Vajpayee", DateTimeUtils.createDate(1920, Calendar.AUGUST, 9), Gender.MALE);
final Person person9 = new Person(104L, "Soniya", "Rajiv", "Gandhi", DateTimeUtils.createDate(1929, Calendar.MARCH, 27), Gender.FEMALE);
final Person person10 = new Person(104L, "Priyanka", "Robert", "Gandhi", DateTimeUtils.createDate(1973, Calendar.APRIL, 15), Gender.FEMALE);
final Person person11 = new Person(104L, "Murali", "Manohar", "Joshi", DateTimeUtils.createDate(1923, Calendar.APRIL, 25), Gender.MALE);
final Person person12 = new Person(104L, "Lalkrishna", "Parmhansh", "Advani", DateTimeUtils.createDate(1910, Calendar.JANUARY, 01), Gender.MALE);
final Person person13 = new Person(104L, "Shushma", "kumari", "Swaraj", DateTimeUtils.createDate(1943, Calendar.AUGUST, 10), Gender.FEMALE);
final Person person14 = new Person(104L, "Arun", "raman", "jetly", DateTimeUtils.createDate(1942, Calendar.OCTOBER, 27), Gender.MALE);
final Person person15 = new Person(104L, "Amit", "kumar", "shah", DateTimeUtils.createDate(1958, Calendar.DECEMBER, 21), Gender.MALE);
final Person person16 = new Person(104L, "Shila", "kumari", "Dixit", DateTimeUtils.createDate(1927, Calendar.FEBRUARY, 15), Gender.FEMALE);
Map< String, Object> userMap = new HashMap< String, Object>();
userMap.put( "2", person6);
userMap.put( "3", person6);
userMap.put( "4", person6);
userMap.put( "5", person6);
userMap.put( "6", person6);
userMap.put( "7", person7);
userMap.put( "8", person8);
userMap.put( "9", person9);
userMap.put( "10", person10);
userMap.put( "11", person11);
userMap.put( "12", person12);
userMap.put( "13", person13);
userMap.put( "14", person14);
userMap.put( "15", person15);
userMap.put( "16", person16);
//putAll all person
region.putAll(userMap);
System.out.println( "successfully Put set of Person objects into the cache");
}
}
#1b. REST Client Utilities (RestClientUtils.java)
package org.apache.geode.util;
import java.net.URI;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.List;
import org.springframework.http.converter.ByteArrayHttpMessageConverter;
import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.StringHttpMessageConverter;
import org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;
import org.springframework.web.client.RestTemplate;
import org.springframework.web.util.UriComponentsBuilder;
public class RestClientUtils {
public static final String BASE_URL = "http://192.0.2.0:8080" ;
public static final String GEODE_REST_API_CONTEXT = "/geode";
public static final String GEODE_REST_API_VERSION = "/v1";
public static final URI GEODE_REST_API_WEB_SERVICE_URL = URI
.create(BASE_URL + GEODE_REST_API_CONTEXT + GEODE_REST_API_VERSION);
public static RestTemplate restTemplate;
public static RestTemplate getRestTemplate() {
if (restTemplate == null) {
restTemplate = new RestTemplate();
final List<HttpMessageConverter<?>> messageConverters = new ArrayList<HttpMessageConverter<?>>();
messageConverters.add( new ByteArrayHttpMessageConverter());
messageConverters.add( new StringHttpMessageConverter());
messageConverters.add(createMappingJackson2HttpMessageConverter());
restTemplate.setMessageConverters(messageConverters);
}
return restTemplate;
}
public static HttpMessageConverter< Object> createMappingJackson2HttpMessageConverter() {
final Jackson2ObjectMapperFactoryBean objectMapperFactoryBean = new Jackson2ObjectMapperFactoryBean();
objectMapperFactoryBean.setFailOnEmptyBeans( true);
objectMapperFactoryBean.setIndentOutput( true);
objectMapperFactoryBean.setDateFormat( new SimpleDateFormat( "MM/dd/yyyy"));
objectMapperFactoryBean
.setFeaturesToDisable(com.fasterxml.jackson.databind.DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
objectMapperFactoryBean
.setFeaturesToEnable(
com.fasterxml.jackson.core.JsonParser.Feature.ALLOW_COMMENTS,
com.fasterxml.jackson.core.JsonParser.Feature.ALLOW_SINGLE_QUOTES,
com.fasterxml.jackson.databind.DeserializationFeature.ACCEPT_EMPTY_STRING_AS_NULL_OBJECT);
objectMapperFactoryBean.afterPropertiesSet();
final MappingJackson2HttpMessageConverter httpMessageConverter = new MappingJackson2HttpMessageConverter();
httpMessageConverter.setObjectMapper(objectMapperFactoryBean.getObject());
return httpMessageConverter;
}
public static URI toUri( final String... pathSegments) {
return toUri(GEODE_REST_API_WEB_SERVICE_URL, pathSegments);
}
public static URI toUri( final URI baseUrl, final String... pathSegments) {
return UriComponentsBuilder.fromUri(baseUrl).pathSegment(pathSegments)
.build().toUri();
}
}
#1c. Date and Time Utilities (DateTimeUtils.java)
package org.apache.geode.util;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
/**
* The DateTimeUtils class is a utility class for working with dates and times.
*/
@SuppressWarnings( "unused")
public abstract class DateTimeUtils {
public static Calendar createCalendar( final int year, final int month, final int day) {
final Calendar dateTime = Calendar.getInstance();
dateTime.clear();
dateTime.set(Calendar.YEAR, year);
dateTime.set(Calendar.MONTH, month);
dateTime.set(Calendar.DAY_OF_MONTH, day);
return dateTime;
}
public static Date createDate( final int year, final int month, final int day) {
return createCalendar(year, month, day).getTime();
}
public static String format( final Date dateTime, final String formatPattern) {
return (dateTime != null ? new SimpleDateFormat(formatPattern).format(dateTime) : null);
}
}
#1d. Person Class (Person.java)
package org.apache.geode.domain;
import java.util.Date;
import org.apache.geode.internal.lang.ObjectUtils;
import org.apache.geode.pdx.PdxReader;
import org.apache.geode.pdx.PdxSerializable;
import org.apache.geode.pdx.PdxWriter;
import org.apache.geode.util.DateTimeUtils;
/**
* The Person class is an abstraction modeling a person.
*/
public class Person implements PdxSerializable /*ResourceSupport implements DomainObject< Long>*/ {
private static final long serialVersionUID = 42108163264l;
protected static final String DOB_FORMAT_PATTERN = "MM/dd/yyyy";
private Long id;
private Date birthDate;
private Gender gender;
private String firstName;
private String middleName;
private String lastName;
public Person() {
}
public Person( final Long id) {
this.id = id;
}
public Person( final String firstName, final String lastName) {
this.firstName = firstName;
this.lastName = lastName;
}
public Person( final Long id, final String firstName, final String middleName, final String lastName, Date date, Gender gender) {
this.id = id;
this.firstName = firstName;
this.middleName = middleName;
this.lastName = lastName;
this.birthDate = date;
this.gender = gender;
}
public Long getId() {
return id;
}
public void setId( final Long id) {
this.id = id;
}
public String getFirstName() {
return firstName;
}
public void setFirstName( final String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName( final String lastName) {
this.lastName = lastName;
}
public String getMiddleName() {
return middleName;
}
public void setMiddleName( final String middleName) {
this.middleName = middleName;
}
public Date getBirthDate() {
return birthDate;
}
public void setBirthDate( final Date birthDate) {
this.birthDate = birthDate;
}
public Gender getGender() {
return gender;
}
public void setGender( final Gender gender) {
this.gender = gender;
}
@Override
public boolean equals( final Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof Person)) {
return false;
}
final Person that = (Person) obj;
return (ObjectUtils.equals( this.getId(), that.getId())
|| (ObjectUtils.equals( this.getBirthDate(), that.getBirthDate())
&& ObjectUtils.equals( this.getLastName(), that.getLastName())
&& ObjectUtils.equals( this.getFirstName(), that.getFirstName())));
}
@Override
public int hashCode() {
int hashValue = 17;
hashValue = 37 * hashValue + ObjectUtils.hashCode(getId());
hashValue = 37 * hashValue + ObjectUtils.hashCode(getBirthDate());
hashValue = 37 * hashValue + ObjectUtils.hashCode(getLastName());
hashValue = 37 * hashValue + ObjectUtils.hashCode(getFirstName());
return hashValue;
}
@Override
public String toString() {
final StringBuilder buffer = new StringBuilder( "{ type = ");
buffer.append(getClass().getName());
buffer.append( ", id = ").append(getId());
buffer.append( ", firstName = ").append(getFirstName());
buffer.append( ", middleName = ").append(getMiddleName());
buffer.append( ", lastName = ").append(getLastName());
buffer.append( ", birthDate = ").append(DateTimeUtils.format(getBirthDate(), DOB_FORMAT_PATTERN));
buffer.append( ", gender = ").append(getGender());
buffer.append( " }");
return buffer.toString();
}
@Override
public void fromData(PdxReader pr) {
id = pr.readLong( "id");
firstName = pr.readString( "firstName");
middleName = pr.readString( "middleName");
lastName = pr.readString( "lastName");
birthDate = pr.readDate( "birthDate");
gender = (Gender)pr.readObject( "gender");
}
@Override
public void toData(PdxWriter pw) {
pw.writeLong( "id", id);
pw.writeString( "firstName", firstName);
pw.writeString( "middleName", middleName);
pw.writeString( "lastName", lastName);
pw.writeDate( "birthDate", birthDate);
pw.writeObject( "gender", gender);
}
}
#1e. Gender Class (Gender.java)
package org.apache.geode.domain;
/**
* The Gender enum is a enumeration of genders (sexes).
*/
public enum Gender {
FEMALE,
MALE
}
#2. Ruby REST Client (restClient.rb)
#!/usr/bin/ruby -w
puts "Hello, Ruby!";
# !/usr/bin/env ruby
require 'json'
require 'net/http'
class JsonSerializable
def to_json
hash = {}
hash["@type"] = "org.apache.geode.web.rest.domain.Person"
self.instance_variables.each do |var|
if !var.to_s.end_with?("links")
hash[var.to_s[1..-1]] = self.instance_variable_get var
end
end
hash.to_json
end
def from_json! jsonString
JSON.load(jsonString).each do |var, val|
if !var.end_with?("type")
self.instance_variable_set "@".concat(var), val
end
end
end
end
class Person < JsonSerializable
attr_accessor :id, :firstName, :middleName, :lastName, :birthDate, :gender
def initialize(id = nil, firstName = nil, middleName = nil, lastName = nil )
@id = id
@firstName = firstName
@middleName = middleName
@lastName = lastName
@birthDate = nil
@gender = nil
end
def to_s
s = "{ type = Person, id = #{@id}"
s += ", firstName = #{@firstName}"
s += ", middleName = #{@middleName}"
s += ", lastName = #{@lastName}"
s += ", birthDate = #{@birthDate}"
s += ", gender = #{@gender}"
s += "}"
end
end
if __FILE__ == $0
#p = Person.new(1, "Jon", "T", "Doe")
#puts p
#puts p.inspect
#puts p.to_json
uri = URI("http://localhost:8080/gemfire-api/v1/People/1");
personJson = Net::HTTP::get(uri);
# JSON from server
puts "JSON read from Server for Person with ID 1...\n #{personJson}"
p = Person.new
p.from_json! personJson
# print the Person to standard out
puts "Person is...\n #{p}"
p.id = 1
p.firstName = "Jack"
p.lastName = "Handy"
p.gender = "MALE"
# prints modified Person to standard out
puts "Person modified is...\n #{p}"
puts "JSON sent to Server for Person with ID 1...\n #{p.to_json}"
Net::HTTP.start(uri.hostname, uri.port) do |http|
putRequest = Net::HTTP::Put.new uri.path, { "Content-Type" => "application/json" }
putRequest.body = p.to_json
http.request(putRequest)
end
end
Output from running the Ruby client:
prompt# ruby restClient.rb
Hello, Ruby!
JSON read from Server for Person with ID 1...
{
"@type" : "org.gopivotal.app.domain.Person",
"id" : 1,
"firstName" : "Jane_updated",
"middleName" : "H",
"lastName" : "Doe_updated",
"gender" : "MALE",
"birthDate" : "04/12/1983"
}
Person is...
{ type = Person, id = 1, firstName = Jane_updated, middleName = H, lastName = Doe_updated, birthDate = 04/12/1983, gender = MALE}
Person modified is...
{ type = Person, id = 1, firstName = Jack, middleName = H, lastName = Handy, birthDate = 04/12/1983, gender = MALE}
JSON sent to Server for Person with ID 1...
{"@type":"org.apache.geode.web.rest.domain.Person","id":1,"firstName":"Jack","middleName":"H","lastName":"Handy","birthDate":"04/12/1983","gender":"MALE"}
#3. Python REST Client (restClient.py)
This example uses Python 3 and shows the creation and modification of objects. It uses one external library called requests, which is nearly ubiquitous and avoids having to use HTTP code.
#!/usr/bin/env python3
# This is simple, repetitive and assumes you have created a region called
# "demoRegion".
import sys
import json
import uuid
import requests
REGION = "demoRegion"
BASE_URI = "http://localhost:8080/gemfire-api/v1"
headers = {'content-type': 'application/json'}
person = {'type': 'Person',
'firstName': 'John',
'middleName': 'Q',
'lastName': 'Public',
'birthDate': '1 Jan 1900'}
def resource_uri(res=None, region=REGION):
if res:
return "%s/%s/%s" % (BASE_URI, region, res)
return "%s/%s" % (BASE_URI, region)
print("[*] First, we'll empty out our demo region - DELETE %s" %
requests.delete(resource_uri()))
r = requests.delete(resource_uri())
r.raise_for_status()
print("[*] Now, we'll create 5 demo objects")
keys = []
for i in range(1, 6):
key = uuid.uuid1()
keys.append(key)
person['uuid'] = str(key)
print("\t Creating object with key: POST %s" % key)
r = requests.post(resource_uri(), data=json.dumps(person),
params={'key': key},
headers=headers)
r.raise_for_status()
print("[*] List our keys - GET %s" % resource_uri("keys"))
r = requests.get(resource_uri("keys"))
print(r.text)
print("[*] Here's all our data - GET %s" % resource_uri())
r = requests.get(resource_uri())
print(r.text)
print("[*] Now each key one by one")
for key in keys:
print("Fetching key - GET %s" % resource_uri(res=key))
r = requests.get(resource_uri(res=key))
print(r.text)
print("[*] Now grab one, change the first name to 'Jane' and save it")
print(" GET - %s" % resource_uri(res=keys[0]))
r = requests.get(resource_uri(res=keys[0]))
p = json.loads(r.text)
p['firstName'] = 'Jane'
print(" PUT - %s" % resource_uri(res=keys[0]))
r = requests.put(resource_uri(res=keys[0]), data=json.dumps(p),
headers=headers)
print(" GET - %s" % resource_uri(res=keys[0]))
r = requests.get(resource_uri(res=keys[0]))
print(r.text)
