PagingAndSortingRepository
interface provides 'findAll(Sort sort)' method, it return all entities sorted
by the given options.
Example
// SELECT * FROM my_employee ORDER BY
age, first_name;
Sort sort
= new Sort(Direction.ASC, Arrays.asList("age","firstName"));
Iterable<Employee>
emps = employeeRepository.findAll(sort);
Above
statements get all the employees in sorting order of age and firstName.
Find the
below working application.
Step 1:
Define Employee class
like below.
package com.sample.app.model; import javax.persistence.Column; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.GenerationType; import javax.persistence.Id; import javax.persistence.Table; @Entity @Table(name = "my_employee") public class Employee { @Id @GeneratedValue(strategy = GenerationType.AUTO) private int id; @Column(name = "first_name") private String firstName; @Column(name = "last_name") private String lastName; @Column(name = "age") private int age; @Column(name = "salary") private double salary; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public double getSalary() { return salary; } public void setSalary(double salary) { this.salary = salary; } public static EmployeeBuilder builder() { return new EmployeeBuilder(); } public static class EmployeeBuilder { private Employee emp; public EmployeeBuilder() { emp = new Employee(); } public EmployeeBuilder firstName(String firstName) { emp.setFirstName(firstName); return this; } public EmployeeBuilder lastName(String lastName) { emp.setLastName(lastName); return this; } public EmployeeBuilder age(int age) { emp.setAge(age); return this; } public EmployeeBuilder salary(double salary) { emp.setSalary(salary); return this; } public Employee build() { return emp; } } @Override public String toString() { StringBuilder builder = new StringBuilder(); builder.append("Employee [id=").append(id).append(", firstName=").append(firstName).append(", lastName=") .append(lastName).append(", age=").append(age).append(", salary=").append(salary).append("]"); return builder.toString(); } }
Step 2:
Define EmployeeRepository
like below.
package com.sample.app.repository; import org.springframework.data.repository.PagingAndSortingRepository; import com.sample.app.model.Employee; public interface EmployeeRepository extends PagingAndSortingRepository<Employee, Integer> { }
Step 3:
Create 'application.properties' file under src/main/resources folder.
logging.level.root=WARN logging.level.org.hibernate=ERROR ## H2 specific properties spring.h2.console.enabled=true spring.h2.console.path=/h2 spring.datasource.url=jdbc:h2:file:~/db/myOrg.db;DB_CLOSE_ON_EXIT=FALSE;DB_CLOSE_DELAY=-1; spring.datasource.username=krishna spring.datasource.password=password123 spring.datasource.driverClassName=org.h2.Driver ## JPA specific properties # Creates the schema, destroying previous data. spring.jpa.hibernate.ddl-auto=create spring.jpa.database-platform=org.hibernate.dialect.H2Dialect spring.jpa.show-sql=true spring.jpa.properties.hibernate.format_sql=true ## Database connection pooling properties # Number of ms to wait before throwing an exception if no connection is available. spring.datasource.max-wait=10000 # Maximum number of active connections that can be allocated from this pool at the same time. spring.datasource.tomcat.max-active=10 spring.datasource.tomcat.max-idle=5 spring.datasource.tomcat.min-idle=3
Step 4:
pom.xml looks like
below.
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>springJPA</groupId> <artifactId>springJPA</artifactId> <version>1</version> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.6.RELEASE</version> </parent> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> </properties> <dependencies> <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-data-jpa --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <!-- https://mvnrepository.com/artifact/com.h2database/h2 --> <dependency> <groupId>com.h2database</groupId> <artifactId>h2</artifactId> </dependency> </dependencies> </project>
Step 5:
Define App.java like
below.
App.java package com.sample.app; import java.util.Arrays; import org.springframework.boot.CommandLineRunner; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.context.annotation.Bean; import org.springframework.data.domain.Sort.Direction; import com.sample.app.model.Employee; import com.sample.app.repository.EmployeeRepository; import org.springframework.data.domain.Sort; @SpringBootApplication public class App { public static void main(String args[]) { SpringApplication.run(App.class, args); } @Bean public CommandLineRunner demo(EmployeeRepository employeeRepository) { return (args) -> { Employee emp1 = Employee.builder().firstName("Ram").lastName("Gurram").age(32).salary(100000.23).build(); Employee emp2 = Employee.builder().firstName("Joel").lastName("Chelli").age(43).salary(60000).build(); Employee emp3 = Employee.builder().firstName("Gopi").lastName("Battu").age(45).salary(1000000).build(); Employee emp4 = Employee.builder().firstName("Bomma").lastName("Srikanth").age(39).salary(60000).build(); Employee emp5 = Employee.builder().firstName("Surendra").lastName("Sami").age(32).salary(100000.23).build(); employeeRepository.save(emp1); employeeRepository.save(emp2); employeeRepository.save(emp3); employeeRepository.save(emp4); employeeRepository.save(emp5); //SELECT * FROM my_employee ORDER BY age, first_name; Sort sort = new Sort(Direction.ASC, Arrays.asList("age","firstName")); Iterable<Employee> emps = employeeRepository.findAll(sort); for(Employee emp: emps) { System.out.println(emp); } }; } }
Total
project structure looks like below.
Run App.java, you can see below messages in console.
. ____ _ __ _ _
/\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \
( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \
\\/ ___)| |_)| | | | | || (_| | ) ) ) )
' |____| .__|_| |_|_| |_\__, | / / / /
=========|_|==============|___/=/_/_/_/
:: Spring Boot :: (v2.1.6.RELEASE)
Hibernate:
drop table my_employee if exists
Hibernate:
drop sequence if exists hibernate_sequence
Hibernate: create sequence hibernate_sequence start with 1 increment by 1
Hibernate:
create table my_employee (
id integer not null,
age integer,
first_name varchar(255),
last_name varchar(255),
salary double,
primary key (id)
)
Hibernate:
call next value for hibernate_sequence
Hibernate:
insert
into
my_employee
(age, first_name, last_name, salary, id)
values
(?, ?, ?, ?, ?)
Hibernate:
call next value for hibernate_sequence
Hibernate:
insert
into
my_employee
(age, first_name, last_name, salary, id)
values
(?, ?, ?, ?, ?)
Hibernate:
call next value for hibernate_sequence
Hibernate:
insert
into
my_employee
(age, first_name, last_name, salary, id)
values
(?, ?, ?, ?, ?)
Hibernate:
call next value for hibernate_sequence
Hibernate:
insert
into
my_employee
(age, first_name, last_name, salary, id)
values
(?, ?, ?, ?, ?)
Hibernate:
call next value for hibernate_sequence
Hibernate:
insert
into
my_employee
(age, first_name, last_name, salary, id)
values
(?, ?, ?, ?, ?)
Hibernate:
select
employee0_.id as id1_0_,
employee0_.age as age2_0_,
employee0_.first_name as first_na3_0_,
employee0_.last_name as last_nam4_0_,
employee0_.salary as salary5_0_
from
my_employee employee0_
order by
employee0_.age asc,
employee0_.first_name asc
Employee [id=1, firstName=Ram, lastName=Gurram, age=32, salary=100000.23]
Employee [id=5, firstName=Surendra, lastName=Sami, age=32, salary=100000.23]
Employee [id=4, firstName=Bomma, lastName=Srikanth, age=39, salary=60000.0]
Employee [id=2, firstName=Joel, lastName=Chelli, age=43, salary=60000.0]
Employee [id=3, firstName=Gopi, lastName=Battu, age=45, salary=1000000.0]
You can
download the complete working application from this location.
No comments:
Post a Comment