Comparison of some of the most widely used NoSQL databases and their usage from Java.

The applications try to demonstrate the use cases where NoSQL databases can be considered as an alternative for traditional relational database management systems.

The applications are built using Spring Boot and AngularJS, the initial project structure was generated using JHipster.

Generally:

% cd [cassandra|mongodb|mysql|oracle]
% npm install && bower install
% mvn

After installing npm and bower dependencies, Maven will build the application and run it with an embedded web server using Spring Boot and Tomcat. The application can be tested by opening up a browser and hitting http://localhost:8080.

The databases have to be started before running the applications. For databases other than Cassandra the database objects are created automatically during application launch. In the case of Oracle and MySQL, an initial schema has to be created but database objects (tables, indexes, etc.) are created automatically by Liquibase.

When using Cassandra, the below files containing CQL statements have to be executed manually from the CQL interactive terminal cqlsh before running the application:

% cd cassandra/src/main/resources/config/cql
% cqlsh
cqlsh> USE ontime;
cqlsh> SOURCE 'create-keyspace.cql'
cqlsh> SOURCE 'create-tables-auth.cql'
cqlsh> SOURCE 'create-tables-domain.cql'

Cassandra should be running on the default 9042 port.

Mongeez manages the database initialization. MongoDB should be running on the default 27177 port.

The initial schema should be created:

CREATE SCHEMA ontime;

In the application-dev.yml file of the src/resources/config folder the database user's password should be added. MySQL should be running on the default 3306 port.

For Oracle XE database, the initial schema can be created using the following commands (where <<SECRET>> has to be substituted with an appropriate password):

CREATE USER ontime IDENTIFIED BY <<SECRET>>
  DEFAULT TABLESPACE "USERS"
  TEMPORARY TABLESPACE "TEMP";
GRANT "CONNECT" TO ontime;
GRANT "RESOURCE" TO ontime;

The user's password should be added to the src/resources/config/application-dev.yml file.

When testing the Oracle application the test URL was changed to http://localhost:8081 as Oracle XE Database Home Page is running on port 8080. Oracle database itself should be running on the default 1521 port.

Databases:

• MongoDB
• Cassandra
• Ehcache
• MySQL
• Oracle XE

Server-side:

• Spring Boot
• Java 8

Client-side:

• AngularJS

cd doc
make all