In this
post, I am going to explain how to create read only repository (where you can’t
perform update, delete operations).
Step 1:
Create
'ReadOnlyRepository' interface that extends Repository interface and annotate
this interface with @NoRepositoryBean annotation.
@NoRepositoryBean public interface ReadOnlyRepository<T, ID> extends Repository<T, ID> { }
Step 2:
Add read methods to ReadOnlyRepository
interface.
@NoRepositoryBean public interface ReadOnlyRepository<T, ID> extends Repository<T, ID> { <S extends T> S save(S entity); <S extends T> Iterable<S> saveAll(Iterable<S> entities); Optional<T> findById(ID id); boolean existsById(ID id); Iterable<T> findAll(); Iterable<T> findAllById(Iterable<ID> ids); long count(); }
Step 3:
Now extend 'ReadOnlyRepository'
to work with these read methods.
public interface EmployeeRepository extends ReadOnlyRepository<Employee, Integer> { }
That’s it
you are done.
Find the
below working application.
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 Integer id; @Column(name = "first_name") private String firstName; @Column(name = "last_name") private String lastName; @Column(name = "age") private Integer age; @Column(name = "salary") private Double salary; public Integer getId() { return id; } public void setId(Integer 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 Integer getAge() { return age; } public void setAge(Integer 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(); } }
ReadOnlyRepository.java
package com.sample.app.repository; import java.util.Optional; import org.springframework.data.repository.NoRepositoryBean; import org.springframework.data.repository.Repository; @NoRepositoryBean public interface ReadOnlyRepository<T, ID> extends Repository<T, ID> { <S extends T> S save(S entity); <S extends T> Iterable<S> saveAll(Iterable<S> entities); Optional<T> findById(ID id); boolean existsById(ID id); Iterable<T> findAll(); Iterable<T> findAllById(Iterable<ID> ids); long count(); }
EmployeeRepository.java
package com.sample.app.repository; import com.sample.app.model.Employee; public interface EmployeeRepository extends ReadOnlyRepository<Employee, Integer> { }
App.java
package com.sample.app; 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.jpa.repository.config.EnableJpaAuditing; import com.sample.app.model.Employee; import com.sample.app.repository.EmployeeRepository; @SpringBootApplication @EnableJpaAuditing 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(32).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(); Employee emp6 = Employee.builder().firstName("Bhadri").lastName("Venakata RamaRao").age(32) .salary(100000.23).build(); Employee emp7 = Employee.builder().firstName("Sushmithaa").lastName("Kulakarni").age(39).salary(100000.23) .build(); employeeRepository.save(emp1); employeeRepository.save(emp2); employeeRepository.save(emp3); employeeRepository.save(emp4); employeeRepository.save(emp5); employeeRepository.save(emp6); employeeRepository.save(emp7); Iterable<Employee> emps = employeeRepository.findAll(); for (Employee emp : emps) { System.out.println(emp); } }; } }
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
Total
project structure looks like below.
Run
App.java, you can see below messages in console.
. ____ _ __ _ _ /\\ / ___'_ __ _ _(_)_ __ __ _ \ \ \ \ ( ( )\___ | '_ | '_| | '_ \/ _` | \ \ \ \ \\/ ___)| |_)| | | | | || (_| | ) ) ) ) ' |____| .__|_| |_|_| |_\__, | / / / / =========|_|==============|___/=/_/_/_/ :: Spring Boot :: (v2.1.6.RELEASE) Employee [id=1, firstName=Ram, lastName=Gurram, age=32, salary=100000.23] Employee [id=2, firstName=Joel, lastName=Chelli, age=43, salary=60000.0] Employee [id=3, firstName=Gopi, lastName=Battu, age=32, salary=1000000.0] Employee [id=4, firstName=Bomma, lastName=Srikanth, age=39, salary=60000.0] Employee [id=5, firstName=Surendra, lastName=Sami, age=32, salary=100000.23] Employee [id=6, firstName=Bhadri, lastName=Venakata RamaRao, age=32, salary=100000.23] Employee [id=7, firstName=Sushmithaa, lastName=Kulakarni, age=39, salary=100000.23]
You can
download the complete working application from this link.
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