tkint / mini-dao

License	Master	Develop	Version

MiniDAO

MiniDAO is a java library created to form a quick connection between java model and database.

Its purpose is to simplify requests, but it is not made for creating a database automatically. I will maybe add a feature to execute scripts on initialization, or to expose a maven job, a bit like Artisan and Eloquent in PHP.

If you want to participate, I'm fully open to it. If you want a new feature incorporated or encounter a bug, don't hesitate to fill an issue.

Summary

• Quick Start
  • Maven dependency
  • Simple use case
• Installation
  • Through git
  • Download and install ojdbc8
  • Install ojdbc8 during maven build
• Annotations
  • @MDEntity
  • @MDField
  • @MDId
  • @MDInheritLink
  • @MDManyToOne
  • @MDOneToMany
• Configuration
• Main class : MiniDAO
  • read() - MDRead
  • create() - MDCreate
  • update() - MDUpdate
  • delete() - MDDelete
• Query Builders
  • MDSelectBuilder
  • MDInsertBuilder
  • MDUpdateBuilder
  • MDDeleteBuilder
• Development
• License

Quick Start

Maven dependency

Add those lines in your pom.xml:

<dependencies>
    <!-- Other dependencies -->
    <dependency>
        <groupId>com.thomaskint</groupId>
        <artifactId>minidao</artifactId>
        <version>{version}</version>
    </dependency>
</dependencies>

Simple use case

Start by creating an MDConnectionConfig object with login informations to your database:

MDConnectionConfig connectionConfig = new MDConnectionConfig(MDDriver.MYSQL, "{url}", "{port}", "{username}", "{password}", "{database}");

For example:

MDConnectionConfig connectionConfig = new MDConnectionConfig(MDDriver.MYSQL, "127.0.0.1", "3306", "minidao", "password", "minidao");

Then, set the library config:

MiniDAO miniDAO = new MiniDAO(connectionConfig);

Create an object reflecting one of your database table:

@MDEntity(tableName = "user")
public class User {
    
    @MDId
    @MDField(fieldName = "id", allowedSQLActions = SELECT)
    public BigDecimal id;
    
    @MDField(fieldName = "email")
    public String email;
    
    @MDField(fieldName = "login")
    public String login;
    
    @MDField(fieldName = "password")
    public String password;
}

Now, you can retrieve data from your database:

public List<User> getUsers() {
    List<User> users = null;
    try {
        users = miniDAO.read().getEntities(User.class);
    } catch (MDException e) {
        e.printStackTrace();
    }
    return users;
}

Installation

Through git

Clone project:

git clone https://gitlab.com/tkint/MiniDAO.git

If ojdbc8 (12.2.0.1) is not already installed in your local maven repository will need to create an oracle account. Then you can either download and install ojdbc8 or install ojdbc8 during maven build

Now, install MiniDAO in your local maven repository:

mvn clean install

Download and install ojdbc8

First of all, you should create an oracle account

Go to oracle website, accept OTN License Agreement and download ojdbc8.jar.

Now, go to your download directory, open a bash and run the following command:

mvn install:install-file -Dfile=ojdbc8.jar -DgroupId=com.oracle -DartifactId=ojdbc8 -Dversion=12.2.0.1 -Dpackaging=jar

It will install ojdbc8 on your local maven repository, making it available to you and MiniDAO.

Install ojdbc8 during maven build

First of all, you should create an oracle account

Next, you have to accept the license agreement

In settings.xml, there are fields for credentials:

<username>{oracle_username}</username>
<password>{oracle_password}</password>

Change {oracle_username} and {oracle_password} respectively by your oracle username and password.

Now, next time you want to install MiniDAO in your local maven repository, you will have to run the following command:

mvn clean install -s settings.xml

It will automatically install MiniDAO and ojdbc8 on your local maven repository based on the oracle credentials you have given.

Annotations

@MDEntity

Define class as an object of database

• constraints:
  • class must be public
  • must have an empty constructor if custom ones are defined
• properties:
  • tableName: table name in database
  • allowedSQLActions: authorized verbs on this entity
    • default: { SELECT, INSERT, UPDATE, DELETE }
• examples:

@MDEntity(tableName = "user")
public class User {
}

@MDEntity(tableName = "user_token", allowedSQLActions = { SELECT, INSERT })
public class UserToken {
}

@MDField

Define field as a column of the entity table

• constraints:
  • field must be public
• properties:
  • fieldName: field name in database
  • allowedSQLActions: authorized verbs on this field
    • default: { SELECT, INSERT, UPDATE, DELETE }
• examples:

@MDEntity(tableName = "user")
public class User {

    @MDField(fieldName = "id", allowedSQLActions = SELECT)
    public BigDecimal id;
    
    @MDField(fieldName = "email")
    public String email;
}

@MDId

Define field as the primary key of the entity table

• constraints:
  • must be on a field annotated with MDField
• examples:

@MDEntity(tableName = "user")
public class User {
    
    @MDId
    @MDField(fieldName = "id", allowedSQLActions = SELECT)
    public BigDecimal id;
    
    @MDField(fieldName = "email")
    public String email;
}

@MDInheritLink

Define field as a link of the entity table to the parent class table

• constraints:
  • must be on a field annotated with MDField
  • MDField must be a foreign key referencing the parent entity primary key
• examples:

@MDEntity(tableName = "user")
public class User {
    
    @MDId
    @MDField(fieldName = "id", allowedSQLActions = SELECT)
    public BigDecimal id;
    
    @MDField(fieldName = "email")
    public String email;
}

@MDEntity(tableName = "player")
public class Player extends User {
    
	@MDId
	@MDField(fieldName = "id_player")
	public BigDecimal idPlayer;
    
	@MDInheritLink
	@MDField(fieldName = "id_user")
	public BigDecimal idUser;

	@MDField(fieldName = "pseudo")
	public String pseudo;
}

NB: This feature is not really useful, I made it as a Proof of Concept for linking entities between them before making @MDManyToOne and @MDOneToMany

@MDManyToOne

Define field as a foreign key link to the referenced entity

• constraints:
  • field must be public
  • field must be an MDEntity object reference
  • field must NOT be annotated with MDField
• properties:
  • fieldName: field name of the link key in database
  • targetFieldName: field name of the target key
  • target: entity to link
  • loadPolicy:
    • LAZY: avoid loading of linked entity when current one is retrieved
    • HEAVY: force loading of linked entity when current one is retrieved
• examples:

@MDEntity(tableName = "user")
public class User {
    
    @MDId
    @MDField(fieldName = "id", allowedSQLActions = SELECT)
    public BigDecimal id;
    
    @MDField(fieldName = "email")
    public String email;
}

@MDEntity(tableName = "user_token")
public class UserToken {
    
    @MDManyToOne(fieldName = "id_user", targetFieldName = "id", target = User.class, loadPolicy = HEAVY)
    public User user;
    
    @MDField(fieldName = "token")
    public String token;
}

@MDOneToMany

Define field as a foreign key link to the referenced entity

• constraints:
  • field must be public
  • field must be a collection of MDEntity object
  • field must NOT be annotated with MDField
• properties:
  • fieldName: field name of the link key in database
  • targetFieldName: field name of the target foreign key
  • target: entity to link
  • loadPolicy:
    • LAZY: avoid loading of linked entity when current one is retrieved
    • HEAVY: force loading of linked entity when current one is retrieved
• examples:

@MDEntity(tableName = "user")
public class User {
    
    @MDId
    @MDField(fieldName = "id", allowedSQLActions = SELECT)
    public BigDecimal id;
    
    @MDField(fieldName = "email")
    public String email;

    @MDOneToMany(fieldName = "id", targetFieldName = "id_user", target = UserToken.class, loadPolicy = HEAVY)
    public List<UserToken> userTokens;
}

@MDEntity(tableName = "user_token")
public class UserToken {
    
    @MDManyToOne(fieldName = "id_user", targetFieldName = "id", target = User.class, loadPolicy = HEAVY)
    public User user;
    
    @MDField(fieldName = "token")
    public String token;
}

Configuration

The MDConnectionConfig object allow you to setup a connection with a database. You can instantiate multiple MiniDAO connections and MDConnectionConfig.

This object has the following properties:

• MDDriver driver:
  The driver is used by MiniDAO to build the uri and instantiate Connection.
  For now, supported drivers are MYSQL, ORACLE and H2 (file only). In the future, MiniDAO will be able to do specific requests based on this value.
• String url:
  Ip address or domain name of the database server
• String port:
  Port used to access database server instance
• String login:
  Login of the user
• String password:
  Password of the user
• String instance:
  Name of database

Main class : MiniDAO

read() - MDRead

In progress

create() - MDCreate

In progress

update() - MDUpdate

In progress

delete() - MDDelete

In progress

Query Builders

When the default methods are not enough to get what you want, you can use Query Builders to make your own queries and execute them.

MDSelectBuilder

public class UserRetriever {
    	
    private MiniDAO miniDAO;
    
    public UserRetriever(MiniDAO miniDAO) {
        this.miniDAO = miniDAO;
    }
	
    public List<User> getUsersByFirstName(String firstName) throws MDException {
        MDSelectBuilder selectBuilder = new MDSelectBuilder();
        selectBuilder.select().from(User.class).where("first_name", EQUAL, firstName);
        String query = selectBuilder.build();
        
        ResultSet resultSet;
        List<User> users;
        try {
        	resultSet = miniDAO.executeQuery(query);
        	users = miniDAO.mapResultSetToEntities(resultSet, User.class);
        } catch (MDException exception) {
        	throw exception;
        }
        
        return users;
    }
}

MDInsertBuilder

In progress

MDUpdateBuilder

In progress

MDDeleteBuilder

In progress

License

MiniDAO is developed and distributed under the terms of the MIT License