Using Java to operate eXtremeDB
Using Java to operate eXtremeDB can be achieved through the eXtremeDB Java API. The following are the steps to operate eXtremeDB using Java:
1. Add Maven dependency: Add the following dependencies in the pom.xml file:
<dependency>
<groupId>com.extremedb</groupId>
<artifactId>edbjni</artifactId>
<version>7.0.0</version>
</dependency>
2. Create an eXtremeDB database connection: First, import the relevant classes and packages:
import com.extremedb.Database;
import com.extremedb.Session;
import com.extremedb.exceptions.DatabaseNotFoundException;
import com.extremedb.exceptions.SessionNotFoundException;
Then create an eXtremeDB database connection in the code and obtain the Session object:
try {
Database database=new Database ("path/to/database")// Database file path
Session session = database.startSession();
//Using a session to operate the eXtremeDB database
}Catch (DatabaseNotFoundException | SessionNotFoundException e){
e.printStackTrace();
}
3. Data insertion: Use the Session object to insert data. Firstly, create a class to represent entities in the database:
import com.extremedb.*;
public class PersonRecord extends Record {
public String firstName;
public String lastName;
public int age;
}
Then, execute the following code to insert the data:
PersonRecord person = new PersonRecord();
person.firstName = "John";
person.lastName = "Doe";
person.age = 25;
session.begin();
session.create(person);
session.commit();
4. Data Query: Use Session objects to query data. Here is a simple example:
Filter filter = new Filter();
filter.addEqual("firstName", "John");
PersonRecord[] results = session.getRecords(PersonRecord.class, filter);
for (PersonRecord person : results) {
System.out.println(person.firstName + " " + person.lastName + " - " + person.age);
}
5. Data modification: Use the Session object to modify data. Here is an example:
Filter filter = new Filter();
filter.addEqual("lastName", "Doe");
PersonRecord[] results = session.getRecords(PersonRecord.class, filter);
for (PersonRecord person : results) {
person.lastName = "Smith";
session.modify(person);
session.commit();
}
6. Data deletion: Use the Session object to delete data. Here is an example:
Filter filter = new Filter();
filter.addEqual("lastName", "Smith");
PersonRecord[] results = session.getRecords(PersonRecord.class, filter);
for (PersonRecord person : results) {
session.delete(person);
session.commit();
}
Note: The above code is only for example and needs to be adjusted according to the specific situation during actual use.
The above are the basic steps and sample code for using Java to operate eXtremeDB. Using the eXtremeDB Java API can achieve more functions, such as data updates, index creation, transaction management, and so on. For detailed usage methods, please refer to the official documentation of eXtremeDB.
