tsk18.java

package a;

import com.zaxxer.hikari.HikariConfig;
import com.zaxxer.hikari.HikariDataSource;
import lombok.*;
import org.jetbrains.annotations.Nullable;
import org.jetbrains.annotations.TestOnly;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.actuate.endpoint.annotation.Endpoint;
import org.springframework.boot.actuate.endpoint.annotation.ReadOperation;
import org.springframework.boot.actuate.endpoint.annotation.WriteOperation;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.data.repository.NoRepositoryBean;
import org.springframework.orm.hibernate5.HibernateTransactionManager;
import org.springframework.orm.hibernate5.LocalSessionFactoryBean;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Repository;
import org.springframework.stereotype.Service;
import org.springframework.transaction.PlatformTransactionManager;

import javax.persistence.*;
import javax.sql.DataSource;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import java.util.Objects;
import java.util.Properties;

/*
sudo mkdir /run/postgresql
sudo chgrp postgres /run/postgresql
sudo chown postgres /run/postgresql
sudo su - postgres
 pg_ctl -D /var/lib/postgres/data start
 psql -d db
 select * from urs;
 select * from dgs;
 pg_ctl -D /var/lib/postgres/data stop

management.endpoints.web.exposure.include=usr,dg
*/
@SpringBootApplication
public class tsk18 {
 private static final String db = "db";
 private static final String tb1 = "urs";
 private static final String tb2 = "dgs";

 public static void main(String[] args)
 { SpringApplication.run(tsk18.class, args); }

 ////////////////////////////////////////////////////////////////////// configuration

 @Configuration @EnableJpaRepositories(considerNestedRepositories = true)
 public static class A {

 @Bean public DataSource ds() {
 val a = new HikariConfig();
 a.setJdbcUrl("jdbc:postgresql://localhost:5432/" + db);
 a.setDriverClassName("org.postgresql.Driver");
 a.setUsername("postgres");
 a.setPassword("postgres");
 return new HikariDataSource(a);
 }

 @Bean(name = "entityManagerFactory")
 public LocalSessionFactoryBean fc(DataSource b) {
 val a = new LocalSessionFactoryBean();
 a.setDataSource(b);
 a.setPackagesToScan(this.getClass().getPackageName());

 val c = new Properties();
 c.setProperty("hibernate.dialect",
 "org.hibernate.dialect.PostgreSQL92Dialect");
 c.setProperty("hibernate.show_sql", "true");
 c.setProperty("hibernate.hbm2ddl.auto", "update");
 a.setHibernateProperties(c);
 return a;
 }

 @Bean(name = "transactionManager")
 public PlatformTransactionManager
 pt(LocalSessionFactoryBean a) {
 return new HibernateTransactionManager(
 Objects.requireNonNull(a.getObject())); }
 }

 ////////////////////////////////////////////////////////////////////// service

 private interface $$<T extends _$, R extends $$$$<T>>
 { List<T> gal(); void dd(T a); void dl(int a);
 @TestOnly void nw(); @TestOnly String gt(); }

 public interface uss extends $$<usr, usp> {}
 public interface dgs extends $$<dg, dgp> {}

 @RequiredArgsConstructor
 private abstract static class
 $$$<T extends _$, R extends $$$$<T>> implements $$<T, R> {
 private final R rp;

 @Override public List<T> gal() { return rp.findAll(); }
 @Override public void dd(T a) { rp.save(a); }
 @Override public void dl(int a) { rp.deleteById(a); }

 @SuppressWarnings("unchecked")
 @TestOnly @Override
 public void nw() { dd((T) (
 rp instanceof usp ?
 new usr("fn", "ln") :
 new dg("nm", "bd"))); }

 @TestOnly @Override
 public String gt() { return gal().toString(); }
 }

 // GET curl http://localhost:8080/actuator/usr
 @Component @Endpoint(id = "usr") @Service
 public static class ussi extends $$$<usr, usp> implements uss {
 public ussi(usp a) { super(a); }

 @SuppressWarnings("unused") @ReadOperation
 public String a() { return gt(); }
 }

 // GET curl http://localhost:8080/actuator/dg
 @Component @Endpoint(id = "dg") @Service
 public static class dgsi extends $$$<dg, dgp> implements dgs {
 public dgsi(dgp a) { super(a); }

 @SuppressWarnings("unused") @ReadOperation
 public String a() { return gt(); }
 }

 ////////////////////////////////////////////////////////////////////// repository

 @NoRepositoryBean public interface
 $$$$<T extends _$> extends JpaRepository<T, Integer> {}

 @Repository public interface usp extends $$$$<usr> {}
 @Repository public interface dgp extends $$$$<dg> {}

 ////////////////////////////////////////////////////////////////////// data

 @MappedSuperclass
 public static abstract class _$ implements Serializable
 { @GeneratedValue(strategy = GenerationType.IDENTITY)
 @Nullable @Id Integer id; }

 @Table(name = tb1) @Entity
 @RequiredArgsConstructor
 public static class usr extends _$ {
 @NonNull String fn;
 @NonNull String ln;

 @OneToMany(
 mappedBy = "rs",
 fetch = FetchType.EAGER)
 List<dg> dgs = new ArrayList<>();

 public usr() {}

 @Override public String toString()
 { return "(%d %s %s %s)"
 .formatted(id, fn, ln, dgs
 .stream()
 .map(a -> "(%d %s %s)"
 .formatted(a.id, a.nm, a.bd))
 .toList()); }
 }

 @Table(name = tb2) @Entity @ToString
 @RequiredArgsConstructor
 public static class dg extends _$ {
 @NonNull String nm;
 @NonNull String bd;

 @ManyToOne
 @Nullable usr rs;

 public dg() {}
 }
}