Using Java to Operate VelocityDB
VelocityDB is a high-performance Object database that can be operated through Java. The following are the steps to operate VelocityDB using Java:
1. Add Maven dependency: Add the following dependencies in the pom.xml file of the project:
<dependency>
<groupId>com.objy.db</groupId>
<artifactId>velocitydb</artifactId>
<version>9.0.0.2</version>
</dependency>
2. Create a database: First, you need to create a VelocityDB instance and open the database connection. You can create and open a database connection using the following code:
import com.objy.db.app.Session;
import com.objy.dqc.Db;
import com.objy.dqc.DbType;
public class VelocityDBExample {
private static final String DATABASE_PATH = "path/to/database";
public static void main(String[] args) {
//Create and open a database connection
Session session = new Session();
session.addLogStream(System.out);
Db.open(session, DATABASE_PATH, true, null, DbType.durable);
//Perform database operations here
//Close database connection
session.close();
}
}
3. Create Entity Class: Create a Java class to represent the data that needs to be stored in VelocityDB. For example:
import com.objy.db.app.ooId;
import com.objy.db.app.ooObj;
public class Person extends ooObj {
private String name;
private int age;
public Person() {
}
public Person(String name, int age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
4. Data insertion: Use the following code to insert data into VelocityDB:
//Create a Person object
Person person = new Person("John Doe", 30);
//Save Person object to database
person.store();
5. Data modification: Get the object's' ooId 'and use the' set 'method to modify the object's properties, and then call the' store 'method to save the changes to the database. For example:
//Obtain the ooId of the Person object
ooId personOid = person.getOid();
//Obtain object through ooId
Person storedPerson = (Person) ooObj.store().objectWithOid(personOid);
//Modify the properties of an object
storedPerson.setAge(35);
//Save modifications to database
storedPerson.store();
6. Data Query: Use the following code to query data from VelocityDB:
//Query all objects of the specified type
ooObj[] objects = ooObj.store().getAllInstances(Person.class);
//Traverse query results
for (ooObj obj : objects) {
Person person = (Person) obj;
System.out.println("Name: " + person.getName() + ", Age: " + person.getAge());
}
7. Data deletion: Use the following code to delete data from VelocityDB:
//Delete Object
person.deleteObject();
These steps demonstrate how to operate VelocityDB using Java. You can expand and modify as needed.
