Connect to OceanBase Database by using Spring Batch

This topic provides a Spring Batch connection example.

Environment configuration

• JDK 1.8

• OceanBase Database V3.x (MySQL mode or Oracle mode)

• Spring Batch integrated based on Spring Boot

Configuration dependencies

  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-batch</artifactId>
  </dependency>
  <!--Database driver-->
  <dependency>
   <groupId>mysql</groupId>
   <artifactId>mysql-connector-java</artifactId>
   <version>8.0.25</version>
  </dependency>
  <!--Connection pool-->
  <dependency>
   <groupId>com.alibaba</groupId>
   <artifactId>druid</artifactId>
   <version>1.1.22</version>
  </dependency>
  <!--Automatic table creation based on entity classes-->
  <dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-data-jpa</artifactId>
  </dependency>

  <!--Other Spring Boot dependencies are omitted here.-->

Configuration files

# yml file:
spring:
  datasource:
    url: jdbc:mysql://10.100.xxx.xxx:18815/test
    driver-class-name: com.mysql.cj.jdbc.Driver
#    username: admin@mysql
    username: admin@oracle
    password: ******
  jpa:
    hibernate:
      ddl-auto: update

Sample code

Call the database write class method to write data. The specific steps are as follows:

1. Create required classes.

   Entity classes: People and PeopleDESC

   // Basic People class
   
   @Entity
   @Table(name = "PEOPLE")
   public class People {
       @Id
       @GeneratedValue
       private int id;
       private String lastName;
       private String firstName;
       //...Omitted
   }
   

   // The PeopleDESC class after data processing, with the desc attribute added
   
   @Entity
   @Table(name = "OK_PEOPLE")
   public class PeopleDESC {
   
       @Id
       @GeneratedValue  //strategy = AUTO / IDENTITY / SEQUENCE  None of the three primary key generation strategies are supported.
       private int id;
       private String lastName;
       private String firstName;
       private String desc1;
       //...Omitted
   }
   

   Batch processing class: AddPeopleDescProcessor

   // The processor that adds the desc attribute to the People class and returns the PeopleDESC class.
   
   public class AddPeopleDescProcessor implements ItemProcessor<People, PeopleDESC> {
   
       public PeopleDESC process(People item) throws Exception {
   
           return new PeopleDESC(item.getId() ,
                                 item.getLastName(),
                                 item.getFirstName(),
                                 Thread.currentThread().getName());
       }
   }
   

   Class that writes PeopleDESC to the database: AddDescPeopleWriter

   // Write PeopleDESC to the classes of the database.
   
   public class AddDescPeopleWriter implements ItemWriter<PeopleDESC> {
       private JdbcTemplate jdbcTemplate;
       public void setDataSource(DataSource dataSource) {
           this.jdbcTemplate = new JdbcTemplate(dataSource);
       }
   
       public JdbcTemplate getJdbcTemplate() {
           return jdbcTemplate;
       }
   
       public void write(List<? extends PeopleDESC> items) throws Exception {
           for (PeopleDESC peopleDESC : items) {
               this.jdbcTemplate
                       .update("insert into ok_people (id,first_name,last_name,desc1) values (?, ?, ?, ?)",
                               peopleDESC.getId(), peopleDESC.getFirstName(),
                               peopleDESC.getLastName(), peopleDESC.getDesc());
           }
       }
   }
   

2. Start the spring-data-jpa project. Tables are automatically created based on the entity classes People and PeopleDESC. The sample result is as follows:

   

3. Add test data to people in batches.

   public void addData(){
           jdbcTemplate = new JdbcTemplate(dataSource);
           StringBuilder stringBuilder = new StringBuilder("");
           for (int i = 1 ; i<=100 ; i++){
               stringBuilder.append("insert into people values ("+i+",'first_test"+i+"','last_test"+i+"');");
               jdbcTemplate.execute(stringBuilder.toString());
               stringBuilder.delete(0, stringBuilder.length());
           }
       }
   

   The test result is as follows:

   

4. Execute the batch processing method.

    public void writerTest() throws Exception {
           // Obtain the result set of the people table.
           String sql = "select * from people;";
           preparedStatement = dataSource.getConnection().prepareStatement(sql);
           ResultSet resultSet = preparedStatement.executeQuery();
           List list = new ArrayList<PeopleDESC>();
           // Process the result set by using the processor that adds the desc attribute, and encapsulate the data into a List<PeopleDESC>.
           while (resultSet.next()){
               People people = peopleRowMapper.mapRow(resultSet, resultSet.getRow());
               PeopleDESC desc = addPeopleDescProcessor.process(people);
               list.add(desc);
           }
           // Call the database write class methods to write data.
           addDescPeopleWriter.setDataSource(dataSource);
           addDescPeopleWriter.write(list);
       }