Using Speedment

<build>

<plugins>

<plugin>

<groupId>com.speedment.enterprise</groupId>

<artifactId>speedment-enterprise-maven-plugin</artifactId>

<version>${speedment.version}</version>

<configuration>

<components>

<component>com.speedment.enterprise.datastore.tool.DataStoreToolBundle</component>

</components>

<appName>${project.artifactId}</appName>

<packageName>${project.groupId}</packageName>

</configuration>

<dependencies>

<dependency>

<groupId>org.postgresql</groupId>

<artifactId>postgresql</artifactId>

<version>${postgresql.version}</version>

<scope>runtime</scope>

[email protected] © 2019

CC BY-NC-ND

</dependency>

<dependency>

<groupId>com.h2database</groupId>

<artifactId>h2</artifactId>

<version>${h2.version}</version>

<scope>runtime</scope>

</dependency>

</dependencies>

</plugin>

</plugins>

</build>

<repositories>

<repository>

<id>speedment-enterprise</id>

<name>Speedment Enterprise Repositories</name>

<url>https://repo.speedment.com/nexus/content/repositories/releases/</url>

</repository>

</repositories>

<pluginRepositories>

<pluginRepository>

<id>speedment-enterprise</id>

<name>Speedment Enterprise Repositories</name>

<url>https://repo.speedment.com/nexus/content/repositories/releases/</url>

</pluginRepository>

</pluginRepositories>

Notice the dependency on H2 (which is declared twice). The dependency must be version 1.4.199 or

greater (not version 197 for instance).

Copy the H2 database file into the project folder (next to the pom.xml). Under Eclipse, refresh the

project node (F5 or « Refresh » in the context menu). The database file has the extension .mv.db.

Generation of the Speedment object classes

Now right-click the project node in Project Explorer view and select ‘Run As’ > ‘Maven Build…’

NOTE : make sure you select « Maven Build… », not « Maven Build ». Notice the « … » after « Maven

Build » !

This dialog box will show up :

[email protected] © 2019

CC BY-NC-ND

In the Goals field, enter ‘speedment:tool’ and click Run.

In the Console view of Eclipse, a lot of files will be downloaded. This will take 1-2 minutes.

This dialog will eventually open :

Change it to :

[email protected] © 2019

CC BY-NC-ND

That is :

Database Type : PostgreSQL

Username : sa

Database and Schema Names : use the name of the file, in uppercase. (This name is the name of the

CATALOG in Data Source Explorer when you create a new connection towards this database).

Use Connection String : « h2database » is the name of the file (extension .mv.db), SCHEMA=<name>

is the name of the SCHEMA. Set this to H2DATABASE.

To sum up : in the example above :

 H2 database filename on disk : ../fc.Database.Northwind/northwind

Please enter a RELATIVE file name here, not absolute.

Typically, the database file is somewhere in your workspace directory and can reliably be

accessed with a relative file path. In the example here, the database file is located in a

directory located next to the project folder.

 Database Name : NORTHWIND (file name in upper case, with no extension)

 Schema : SCHEMA=NORTHWIND

The final connection string is

jdbc:h2:../fc.Database.Northwind/northwind;SCHEMA=NORTHWIND;AUTO_SERVER=TRU

E

[email protected] © 2019

CC BY-NC-ND

Click Connect.

This dialog will now show up :

Quickly check that the database is correctly recognized by the tool, and the tables are indeed listed in

the left pane.

Click Generate. This generates a DatabaseApplication\src\main\json\speedment.json file as well as

all java class files for your database.

There may be NoClassDefFound exception (red console output) when you close the Speedment

generation tool window. This is normal.

When the database schema changes

If your database schema changes, you will need to regenerate the files by using

speedment:generate as a Maven goal.

To recreate the Speedment connection from scratch, delete speedment.json and restart the process

from the beginning.

Writing sample code

You can now create your main application class. You can paste the following source code to connect

to the database and perform a simple Java Stream API query :

public static void main(String... params)

{

H2DatabaseApplication app = new

H2DatabaseApplicationBuilder().build();

SuppliersManager suppliers = app.getOrThrow(SuppliersManager.class);

Optional<String> lastName = suppliers.stream()

.filter(Suppliers.FIRST_NAME.equal("Cornelia"))

.map(Suppliers.LAST_NAME)

[email protected] © 2019

CC BY-NC-ND

.findAny();

if (lastName.isPresent())

System.out.println("Present");

else

}

System.out.println("Not present");

When creating a new H2 database

Only read this section if you plan to create your own H2 database for use with Speedment.

When creating the H2 database, if your database file is called ‘mydatabase.mv.db’, make sure that

the SQL script creating the database tables creates everything in the MYDATABASE schema :

create schema if not exists YOURDATABASE;

SET SCHEMA YOURDATABASE;

CREATE TABLE ...

By default, H2 creates a schema called PUBLIC, which Speedment won’t be able to connect to easily.

It is best to have the filename == database name == schema name. It is then possible to specify the

SCHEMA to connect to with the JDBC connection string, as we did it in the section above.

You can check the database file name and SCHEMA using the Data Source Explorer.

[email protected] © 2019

CC BY-NC-ND