Get started!(IntelliJ IDEA)

Summary

Introduce how to setting up development environment and how to executing basic database access.

Install JDK

You install JDK 8 .

Note

Doma support JDK 9 and JDK 10, 11.

Install IntelliJ IDEA

You install IntelliJ IDEA Community Edition .

Note

In this document, using IntelliJ IDEA Community Edition as IDE. If you use IntelliJ IDEA Ultimate Edition, recommend to you concomitant use with IntelliJ Doma support plugin.

Import template project

You clone simple-boilerplate from GitHub.

$ git clone https://github.com/domaframework/simple-boilerplate.git

You start IntelliJ IDEA and execute Import Project, select the cloned simple-boilerplate.

../_images/idea-welcome.png

You check Import project from external model and select Gradle.

../_images/idea-import-project.png

You check Use auto-import and uncheck Create separate module per source set. Finally you push Finish.

../_images/idea-import-project-settings.png

If the message that is synced successfully is shown at Build tool window then import is success.

Setting of Annotation Processor

You select Open Module Settings from context menu on tool window.

../_images/idea-open-module-settings.png

You open setting screen of Paths of Modules and confirm that Inherit project compile output path is selected. If it is not selected, you select it.

../_images/idea-output-path.png

You open Build, Execution, Deployment > Compiler > Annotation Processors from Preferences. You check Enable annotation processing. You check Module content root. You input gen/production to Production sources directory and input gen/test to Test sources directory. Finally push OK.

../_images/idea-annotation-processors.png

You execute Build Project from menu. By build, the code that is generated by Annotation Processor is output to gen/production. You select Mark Directory as | Generated Sources Root from context menu on Project tool window and add gen/production to source path.

../_images/idea-generated-sources-root.png

Structure of template project

The project source code’s structure is like next.

─ src
  ├── main
  │   ├── java
  │   │   └── boilerplate
  │   │       ├── AppConfig.java
  │   │       ├── dao
  │   │       │   ├── AppDao.java
  │   │       │   └── EmployeeDao.java
  │   │       └── entity
  │   │           └── Employee.java
  │   └── resources
  │       └── META-INF
  │           └── boilerplate
  │               └── dao
  │                   ├── AppDao
  │                   │   ├── create.script
  │                   │   └── drop.script
  │                   └── EmployeeDao
  │                       ├── selectAll.sql
  │                       └── selectById.sql
  └── test
      ├── java
      │   └── boilerplate
      │       ├── DbResource.java
      │       └── dao
      │           └── EmployeeDaoTest.java
      └── resources

Explain about important file.

AppConfig.java
The Configuration that is needed for executing Doma.
AppDao.java
Utility that create/drop the database schema that is using in this application. This is not need in production environment. The script file is under META-INF/boilerplate/dao/AppDao/ and is used for creating and dropping schema.
Employee.java
The Entity classes that correspond to EMPLOYEE table within database.
EmployeeDao.java
The Dao interfaces that is execute getting and updating Employee class. The SQL file is under META-INF/boilerplate/dao/EmployeeDao/ and is used.
EmployeeDaoTest.java
The test that is using EmployeeDao. You can learn about Doma by adding test case to this file. Other test is not affected by updating data because database schema is created and disposed per test method.

SQL file

You open META-INF/boilerplate/dao/EmployeeDao/selectById.sql file. This file is described like next.

select
    /*%expand*/*
from
    employee
where
    id = /* id */0

The /*%expand*/ show that expansioning column list by referencing entity class that is mapped at Java method.

The /* id */ show that Java method parameter value is binding to this SQL.

The 0 that is placed at behind is test data. By including this test data, you can confirm easily that there is not mistake in SQL at executing by tool. Test data is not used at executing Java program.

About detail you reference SQL templates.

Insert

For executing Insert process, you call Dao method that is annotated @Insert annotation.

Execute insert process

You confirm that next code is exists at EmployeeDao.

@Insert
int insert(Employee employee);

Execute insert process by using this code.

You add next code to EmployeeDaoTest.

@Test
public void testInsert() {
    TransactionManager tm = AppConfig.singleton().getTransactionManager();

    Employee employee = new Employee();

    // First transaction
    // Execute inserting
    tm.required(() -> {
        employee.name = "HOGE";
        employee.age = 20;
        dao.insert(employee);
        assertNotNull(employee.id);
    });

    // Second transaction
    // Confirm that inserting is success
    tm.required(() -> {
        Employee employee2 = dao.selectById(employee.id);
        assertEquals("HOGE", employee2.name);
        assertEquals(Integer.valueOf(20), employee2.age);
        assertEquals(Integer.valueOf(1), employee2.version);
    });
}

You execute JUnit and confirm that this code is run.

At that time, created for the inserting SQL is next.

insert into Employee (age, id, name, version) values (20, 100, 'HOGE', 1)

Identifier and version number is automatically setting.

Update

For executing Update process, you call Dao method that is annotated @Update annotation.

Execute update process

You confirm that next code is exists at EmployeeDao.

@Update
int update(Employee employee);

Execute update process by using this code.

You add next code to EmployeeDaoTest.

@Test
public void testUpdate() {
    TransactionManager tm = AppConfig.singleton().getTransactionManager();

    // First transaction
    // Search and update age field
    tm.required(() -> {
        Employee employee = dao.selectById(1);
        assertEquals("ALLEN", employee.name);
        assertEquals(Integer.valueOf(30), employee.age);
        assertEquals(Integer.valueOf(0), employee.version);
        employee.age = 50;
        dao.update(employee);
        assertEquals(Integer.valueOf(1), employee.version);
    });

    // Second transaction
    // Confirm that updating is success
    tm.required(() -> {
        Employee employee = dao.selectById(1);
        assertEquals("ALLEN", employee.name);
        assertEquals(Integer.valueOf(50), employee.age);
        assertEquals(Integer.valueOf(1), employee.version);
    });
}

You execute JUnit and confirm that this code is run.

At that time, created for the updating SQL is next.

update Employee set age = 50, name = 'ALLEN', version = 0 + 1 where id = 1 and version = 0

The version number that is for optimistic concurrency control is automatically increment.

Delete

For executing Delete process, you call Dao method that is annotated @Delete annotation.

Execute delete process

You confirm that next code is exists at EmployeeDao.

@Delete
int delete(Employee employee);

Execute delete process by using this code.

You add next code to EmployeeDaoTest.

@Test
public void testDelete() {
    TransactionManager tm = AppConfig.singleton().getTransactionManager();

    // First transaction
    // Execute deleting
    tm.required(() -> {
        Employee employee = dao.selectById(1);
        dao.delete(employee);
    });

    // Second transaction
    // Confirm that deleting is success
    tm.required(() -> {
        Employee employee = dao.selectById(1);
        assertNull(employee);
    });
}

You execute JUnit and confirm that this code is run.

At that time, created for the deleting SQL is next.

delete from Employee where id = 1 and version = 0

Identifier and version number is specified in search condition.