Category Archives: Spring-boot

SaaS Application Design Discussion – Part IV

In the previous post, I discussed database design for saas application. To continue design discussion for our social pie saas application, in this post, we will discuss a few more ideas about how a user and user’s company will sign up for application. This will be a user story. We are building a SAAS application. To make it more viable, this application will use the freemium and pay model.

In the freemium model – Any company can join and review what reports it will be able to see and what kind of marketing strategies it can design using those reports.
1. 5 Reports
2. Free Marketing Strategies
3. Up to 3 users
4. Limited usage of twitter and Instagram APIs
In pay model – If a company opts to join a pay subscription, it will be able to get more advance reports, will be able to see reports in a different format, and can also get consultation about strategies for marketing.
1. N number of reports – Your data, your freedom
2. Marketing Consultation
3. KPI tracker and notification
4. Up to N users (won’t be implemented in first version)

User Flow

Once the user lands on the home page, he can opt for either model and sign up. An automated email will be sent to the user for a demo or sign up. Upon sign up, where the user will be entering details about himself and his company. This user will be an administrator and he can add other users with custom roles. The same user can go to reports tab and click on sync data. This will get the latest data from social media and update it in the database. Every new request will compare newly fetched data with current data in the database. If the new request has brought changes, it will be updated in the database. When generating reports, this data from the database will be cached.

We will not be fetching any on-the-fly data from Twitter and Instagram. Administrator users will have an option to send reports to other people from the company. There will be an email/download option.

There are some nitty-gritty details that I have not covered in this post. But with this post, we will be starting to develop a Saas application using java and spring-boot.

Database and design discussion – Part III

To continue the development of a spring-based web application, this post will discuss using of Twitter API in saas application. If you want to understand, what we are building, you can read the first two posts of this series where we discussed the design of the application we are building:

In the previous post, we discussed the Instagram API that we will be using. With recent events around Facebook, I have decided not to use Facebook API for application development. We will still use Instagram and Twitter API.

Using Twitter API in SAAS Application

Firstly, Twitter offers different APIs for developers to build applications. We will be using Engagement API. You can find more details Twitter API.

Our goal is to use this Twitter API to collect engagement metrics in the Saas application.

Secondly, Engagement API offers us details about account engagement metrics which can help us to design marketing strategy. Sample response of this API looks like the below:

{
  "Tweet metrics": {
    "902301386880286721": {
      "engagements": "433",
      "favorites": "21",
      "impressions": "72218"
    },
    "902731270274166784": {
      "engagements": "61",
      "favorites": "27",
      "impressions": "7827"
    },
    "907022936564838401": {
      "engagements": "187",
      "favorites": "37",
      "impressions": "1916"
    }
  }
}

Therefore this API provides metrics for tweets, which tweet generated more traffic. The key decision that can be devised based on these metrics is what kind of tweet, moment or incident generates the traffic.

What fields we will use in our database?

In conclusion, we will be using the following fields in our database table TwitterData

tweet id
engagements
impressions
tweet

Twitter is a viable medium. This data will provide small businesses with a key metric about what tweets have worked with their followers and how they can leverage that pattern. Once the small businesses sort out these patterns, they will be able to create a number of tweets to engage with customers. Eventually, the goal here is to help small businesses to attract customers, and repeat customers.

References

Twitter API documentation – Twitter API

Redis Caching with RedisCacheManager

Introduction

In the previous post Redis Caching, we saw how to use Redis caching with all default settings. We didn’t have any Cache Manager or anything, but we were able to cache data. In this post, we will show how to use RedisCacheManager to cache the data. This manager can further be extended to customize the caching configuration even more. But we will not be looking into customization in this post particularly.

Implement CacheManager for RedisCacheManager

Most of the code for this post will be similar to what we implemented in the previous post. We will just show how to use CacheManager.

To implement CacheManager first we remove @EnableCaching annotation from the main class SpringAppCacheApplication. Now we add a new CacheConfig class to configure our cache manager.

Basically, this CacheConfig will define CacheManager which build a redisTemplate to get JedisConnectionFactory which will be our java client to connect to our Redis server. This JedisConnectionFactory will get server host and port properties from application.properties file. The source code will look like below:

package com.betterjavacode.config;


import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cache.CacheManager;
import org.springframework.cache.annotation.CachingConfigurerSupport;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.context.support.PropertySourcesPlaceholderConfigurer;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;

@Configuration
@EnableCaching
@ComponentScan("com.betterjavacode.config")
@PropertySource("classpath:/application.properties")
public class CacheConfig extends CachingConfigurerSupport
{
    private static final Logger LOGGER = LoggerFactory.getLogger(CacheConfig.class);
    private @Value("${spring.redis.host}") String redisHost;
    private @Value("${spring.redis.port}") int redisPort;

    @Bean
    public static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
        return new PropertySourcesPlaceholderConfigurer();
    }

    @Bean
    public JedisConnectionFactory redisConnectionFactory()
    {
        LOGGER.info(" Inside redisConnectionFactory()...");

        JedisConnectionFactory redisConnectionFactory = new JedisConnectionFactory();

        redisConnectionFactory.setHostName(redisHost);
        redisConnectionFactory.setPort(redisPort);
        redisConnectionFactory.setUsePool(true);
        return redisConnectionFactory;
    }

    @Bean
    public RedisTemplate<String, String> redisTemplate(RedisConnectionFactory rf)
    {
        LOGGER.info(" Inside redisTemplate()...");

        RedisTemplate<String, String> redisTemplate = new RedisTemplate<>();
        redisTemplate.setConnectionFactory(redisConnectionFactory());
        return redisTemplate;
    }

    @Bean
    public CacheManager cacheManager(RedisTemplate redisTemplate)
    {
        LOGGER.info(" Inside cacheManager()...");
        RedisCacheManager cacheManager = new RedisCacheManager(redisTemplate);
        cacheManager.setDefaultExpiration(300);
        return cacheManager;
    }
}

Now if we build our application and run it, Spring boot console will show the following output

2018-02-28 20:31:41.913  INFO 9856 --- [ost-startStop-1] o.s.b.w.servlet.FilterRegistrationBean   : Mapping filter: 'requestContextFilter' to: [/*]
2018-02-28 20:31:42.034  INFO 9856 --- [           main] o.s.j.d.DriverManagerDataSource          : Loaded JDBC driver:com.mysql.jdbc.Driver
2018-02-28 20:31:42.244  INFO 9856 --- [           main] j.LocalContainerEntityManagerFactoryBean : Building JPA container EntityManagerFactory for persistence unit 'default'
2018-02-28 20:31:42.288  INFO 9856 --- [           main] o.hibernate.jpa.internal.util.LogHelper  : HHH000204: Processing PersistenceUnitInfo [ name: default        ...]
2018-02-28 20:31:42.495  INFO 9856 --- [           main] org.hibernate.Version                    : HHH000412: Hibernate
 Core {5.2.13.Final}
2018-02-28 20:31:42.499  INFO 9856 --- [           main] org.hibernate.cfg.Environment            : HHH000206: hibernate
.properties not found
2018-02-28 20:31:42.599  INFO 9856 --- [           main] o.hibernate.annotations.common.Version   : HCANN000001: Hiberna
te Commons Annotations {5.0.1.Final}
2018-02-28 20:31:43.688  INFO 9856 --- [           main] org.hibernate.dialect.Dialect            : HHH000400: Using dia
lect: org.hibernate.dialect.MySQL5Dialect
2018-02-28 20:31:43.764  INFO 9856 --- [           main] o.h.e.j.e.i.LobCreatorBuilderImpl        : HHH000423: Disabling
 contextual LOB creation as JDBC driver reported JDBC version [3] less than 4
2018-02-28 20:31:44.684  INFO 9856 --- [           main] j.LocalContainerEntityManagerFactoryBean : Initialized JPA Enti
tyManagerFactory for persistence unit 'default'
2018-02-28 20:31:45.184  INFO 9856 --- [           main] com.betterjavacode.config.CacheConfig    :  Inside redisConnectionFactory()...
2018-02-28 20:31:45.288  INFO 9856 --- [           main] com.betterjavacode.config.CacheConfig    :  Inside redisTemplate()...
2018-02-28 20:31:45.346  INFO 9856 --- [           main] com.betterjavacode.config.CacheConfig    :  Inside cacheManager()...
2018-02-28 20:31:45.985  INFO 9856 --- [           main] s.w.s.m.m.a.RequestMappingHandlerAdapter : Looking for @ControllerAdvice: org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@30946e09: startup dat
e [Wed Feb 28 20:31:37 CST 2018]; root of context hierarchy
2018-02-28 20:31:46.214  INFO 9856 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/cachedemo/v1/companies/{id}/],methods=[GET],produces=[application/json]}" onto public com.betterjavacode.models.Company com.bette
rjavacode.resources.CompanyController.getCompany(int)
2018-02-28 20:31:46.217  INFO 9856 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/cachedemo/v1/companies],methods=[GET],produces=[application/json]}" onto public java.util.List<com.betterjavacode.models.Company>
 com.betterjavacode.resources.CompanyController.getAllCompanies()
2018-02-28 20:31:46.222  INFO 9856 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error]}"onto public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframewo
rk.boot.autoconfigure.web.BasicErrorController.error(javax.servlet.http.HttpServletRequest)
2018-02-28 20:31:46.223  INFO 9856 --- [           main] s.w.s.m.m.a.RequestMappingHandlerMapping : Mapped "{[/error],produces=[text/html]}" onto public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web
.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)
2018-02-28 20:31:46.300  INFO 9856 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/webjars/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-02-28 20:31:46.301  INFO 9856 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-02-28 20:31:46.377  INFO 9856 --- [           main] o.s.w.s.handler.SimpleUrlHandlerMapping  : Mapped URL path [/**/favicon.ico] onto handler of type [class org.springframework.web.servlet.resource.ResourceHttpRequestHandler]
2018-02-28 20:31:47.071  INFO 9856 --- [           main] o.s.j.e.a.AnnotationMBeanExporter        : Registering beans for JMX exposure on startup
2018-02-28 20:31:47.184  INFO 9856 --- [           main] s.b.c.e.t.TomcatEmbeddedServletContainer : Tomcat started on port(s): 8080 (http)
2018-02-28 20:31:47.195  INFO 9856 --- [           main] c.b.S.SpringAppCacheApplication          : Started SpringAppCacheApplication in 10.626 seconds (JVM running for 11.552)

In this console output, we will see our log statements Inside redisConnectionFactory, Inside redisTemplate, Inside cacheManager.

Conclusion

In this short post, we showed how to use RedisCacheManager to configure Redis for a spring boot application.

References

Redis Cache – Redis

Caching: How to use Redis Caching with Spring Boot

In this introductory post, we will show how to use Redis caching in a simple spring boot application. In subsequent posts, we will evaluate different factors of Redis caching. But for now, we will try to focus on the simple problem of providing caching to a rest service that provides companies-related data to the user interface. This data is in a database, but caching will help us improve the performance.

What you need

Java 8
MySQL Database
IntelliJ Editor
Gradle
Redis Server and Redis Desktop Manager

Spring Boot Based Rest Service

As part of this post, we will build a simple spring-boot based rest service. This rest service will provide data related to companies which will be stored in mysql database.

We will be using Gradle to build our dependencies in this project. Important dependencies for this project are spring-boot-starter, spring-boot-jpa and spring-boot-starter-data-redis With all the needed Gradle dependencies, our Gradle script will look like below:

buildscript {
  ext {
    springBootVersion = '1.5.10.RELEASE'
  }
  repositories {
    mavenCentral()
  }
  dependencies {
    classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
  }
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'org.springframework.boot'

group = 'com.betterjavacode'
version = '0.0.1-SNAPSHOT'
sourceCompatibility = 1.8

repositories {
  mavenCentral()
}

jar {
    manifest {
        attributes 'Main-Class':'com.betterjavacode.SpringAppCache.SpringAppCacheApplication'
    }
    baseName= 'SpringAppCache'
    version='0.0.1-SNAPSHOT'
}

dependencies {
  compile('org.springframework.boot:spring-boot-starter')
  compile('org.springframework.data:spring-data-jpa')
  compile('org.springframework.boot:spring-boot-starter-data-redis')
  compile('org.springframework.boot:spring-boot-starter-web')
        compile('org.hibernate.javax.persistence:hibernate-jpa-2.1-api:1.0.0.Final')
        compile('mysql:mysql-connector-java:5.1.6')
        compile('org.hibernate:hibernate-core:5.2.13.Final')   
        compile('org.aspectj:aspectjweaver:1.8.13')
  testCompile('org.springframework.boot:spring-boot-starter-test')
}

Let’s build a model class for the object Company which will look like below:

package com.betterjavacode.models;

import javax.persistence.*;
import java.io.Serializable;

@Entity(name="Company")
@Table(name="company")
public class Company implements Serializable
{
    public Company()
    {

    }

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private int id;
    @Column(nullable=false)
    private String name;
    @Column(nullable=false)
    private String type;

    public Company(int id, String name, String type)
    {
        this.id = id;
        this.type = type;
        this.name = name;
    }

    public int getId()
    {
        return id;
    }

    public void setId(int id)
    {
        this.id = id;
    }

    public String getName()
    {
        return name;
    }

    public void setName(String name)
    {
        this.name = name;
    }

    public String getType()
    {
        return type;
    }

    public void setType(String type)
    {
        this.type = type;
    }
}

We will not be showing any of the middle layer code which is mostly how the data is going to be built.

Our RestController will use an autowired CompanyManager to fetch company data from the database.

Before we build RestController, we will show the configuration that we have annotated in SpringAppCacheApplication main class.

package com.betterjavacode.SpringAppCache;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;

@SpringBootApplication
@EnableAutoConfiguration
@ComponentScan(basePackages = "com.betterjavacode")
@EnableJpaRepositories(basePackages = "com.betterjavacode.repositories")
@EnableCaching
public class SpringAppCacheApplication
{
  public static void main(String[] args) {
    SpringApplication.run(SpringAppCacheApplication.class, args);
  }
}

Here you can see, we have enabled caching with annotation @EnableCaching.

Now in our RestController class CompanyController , this will show annotation of @Cachable that helps decide when to cache data for the incoming request. This annotation caches data that has been fetched for the request based on configuration.

package com.betterjavacode.resources;

import java.util.List;

import com.betterjavacode.interfaces.CompanyManager;
import com.betterjavacode.models.Company;
import org.hibernate.annotations.Cache;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.Cacheable;
import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.*;


import javax.websocket.server.PathParam;

@RestController
@RequestMapping(value="/cachedemo/v1")
public class CompanyController
{


    @Autowired
    public CompanyManager companyManager;


    @RequestMapping(value = "/companies", method= RequestMethod.GET,
    produces = {"application/json"})
    @ResponseStatus(HttpStatus.OK)
    @ResponseBody
    @Cacheable("companies")
    public List<Company> getAllCompanies()
    {
        return companyManager.getAllCompanies();
    }


    @RequestMapping(value = "/companies/{id}/", method = RequestMethod.GET, produces = {"application/json"})
    @ResponseStatus(HttpStatus.OK)
    @ResponseBody
    @Cacheable(value = "company", key = "#id")
    public Company getCompany(@PathVariable("id") int id)
    {
        return companyManager.getCompany(id);
    }
}

Here is a controller, if you see we are caching the data coming from the database with annotation @Cacheable

To make sure data gets cached with Redis server, we will need certain properties where these annotations will help us to cache the data. The properties to configure Redis server are below:

#########################################################################################
## REDIS CACHE
#########################################################################################
spring.cache.type = redis
spring.redis.host = 127.0.0.1
spring.redis.port = 6379

Once you build the project and run it, we will be able to perform the REST requests to fetch data. If we perform the same requests multiple times, we will be able to see the data in redis.

Conclusion

In this post, we showed how to use redis-caching to cache the data for a spring boot based REST service. The code from this post is available to download github

One Tip to Avoid Bouncy Castle Error

java.lang.NoSuchMethodError: org.bouncycastle.math.ec.ECCurve$Fp – Issue

In this post, I will discuss one tip everyone can use to avoid bouncy castle error.

Problem

Recently I was working on building a SOAP webservice where we were using Apache CXF libraries along with Spring boot. We built the webservice, but when we were sending a SOAP request through the client, we kept getting following error:

Caused by: java.lang.NoSuchMethodError: org.bouncycastle.math.ec.ECCurve$Fp.<init>(Ljava/math/BigInteger;Ljava/math/BigInteger;Ljava/math/BigInteger;)V
  at org.bouncycastle.jcajce.provider.asymmetric.util.EC5Util.convertCurve(Unknown Source)
  at org.bouncycastle.jcajce.provider.asymmetric.util.EC5Util.convertPoint(Unknown Source)
  at org.bouncycastle.jcajce.provider.asymmetric.ec.BCECPublicKey.<init>(Unknown Source)
  at org.bouncycastle.jcajce.provider.asymmetric.ec.KeyFactorySpi.engineGeneratePublic(Unknown Source)
  at java.security.KeyFactory.generatePublic(KeyFactory.java:334)
  at sun.security.ssl.HandshakeMessage$ECDH_ServerKeyExchange.<init>(HandshakeMessage.java:1075)
  at sun.security.ssl.ClientHandshaker.processMessage(ClientHandshaker.java:284)
  at sun.security.ssl.Handshaker.processLoop(Handshaker.java:1026)
  at sun.security.ssl.Handshaker.process_record(Handshaker.java:961)
  at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1062)
  at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1375)
  at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1403)
  at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1387)
  at org.apache.http.conn.ssl.SSLSocketFactory.connectSocket(SSLSocketFactory.java:553)
  at org.apache.http.conn.ssl.SSLSocketFactory.connectSocket(SSLSocketFactory.java:412)
  at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:179)
  at org.apache.http.impl.conn.ManagedClientConnectionImpl.open(ManagedClientConnectionImpl.java:328)
  at org.apache.http.impl.client.DefaultRequestDirector.tryConnect(DefaultRequestDirector.java:612)
  at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:447)
  at org.apache.http.impl.client.AbstractHttpClient.doExecute(AbstractHttpClient.java:884)
  at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:82)
  at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:107)
  at org.apache.http.impl.client.CloseableHttpClient.execute(CloseableHttpClient.java:55)
  at org.springframework.ws.transport.http.HttpComponentsConnection.onSendAfterWrite(HttpComponentsConnection.java:121)

A Simple tip to avoid this error –

We tried different things to resolve this issue. We tried to exclude bouncycastle jars from cxf-rt-ws-security dependencies we were using as we were pulling them from other dependencies. But this error would still pop up intermittently. Eventually, I figured out the issue. We had to add this dependency of bouncycastle explicitly as below in our Gradle build file. That’s when the error went away.

compile (‘org.bouncycastle:bcprov-jdk15on:1.56’)

Conclusion

In this post, I showed how to use this one tip to avoid the error caused by the bouncy castle. If you enjoyed this post, subscribe to my blog here.

Code Complete

Another Java Blog

Category Archives: Spring-boot

SaaS Application Design Discussion – Part IV

User Flow

Database and design discussion – Part III

Using Twitter API in SAAS Application

What fields we will use in our database?

References

Redis Caching with RedisCacheManager

Introduction

Implement CacheManager for RedisCacheManager

Conclusion

References

Caching: How to use Redis Caching with Spring Boot

What you need

Spring Boot Based Rest Service

Conclusion

One Tip to Avoid Bouncy Castle Error

java.lang.NoSuchMethodError: org.bouncycastle.math.ec.ECCurve$Fp – Issue

Problem

A Simple tip to avoid this error –

Conclusion