Caused by: jakarta.persistence.PersistenceException: [PersistenceUnit: default] Unable to build Hibernate SessionFactory; nested exception is org.hibernate.exception.JDBCConnectionException: Unable to open JDBC Connection for DDL execution [The connection attempt failed.] [n/a]
        at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.buildNativeEntityManagerFactory(AbstractEntityManagerFactoryBean.java:431)
        at org.springframework.orm.jpa.AbstractEntityManagerFactoryBean.afterPropertiesSet(AbstractEntityManagerFactoryBean.java:400)

Caused by: java.net.UnknownHostException: postgres
        at java.base/sun.nio.ch.NioSocketImpl.connect(NioSocketImpl.java:567)
        at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:327)
        at java.base/java.net.Socket.connect(Socket.java:751)
        at org.postgresql.core.PGStream.createSocket(PGStream.java:260)
        at org.postgresql.core.PGStream.<init>(PGStream.java:121)
        at org.postgresql.core.v3.ConnectionFactoryImpl.tryConnect(ConnectionFactoryImpl.java:140)
        at org.postgresql.core.v3.ConnectionFactoryImpl.openConnectionImpl(ConnectionFactoryImpl.java:268)

APPlication.Props

spring.application.name=student-app


spring.datasource.driver-class-name=org.postgresql.Driver
spring.datasource.url=jdbc:postgresql://postgres:5432/student
spring.datasource.username=ABCD
spring.datasource.password=1234
spring.jpa.hibernate.ddl-auto=update
spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect

server.port=8090

docker-compose

version: '3.7'

services:
  app:
    build: .
    ports:
      - "8090:8080"
    depends_on:
      - postgres
    networks:
      - mynetwork
      
  postgres:
    image: postgres:latest
    environment:
      POSTGRES_USER: ABCD
      POSTGRES_PASSWORD: 1234
      POSTGRES_DB: student
    ports:
      - "5433:5432"
    networks:
      - mynetwork

networks:
  mynetwork:
    driver: bridge

Dockerfile

FROM openjdk:25-slim-bullseye

ADD target/spring-postgres-docker.jar tmp/spring-postgres-docker.jar

ENTRYPOINT [ "java", "-jar" ,"tmp/spring-postgres-docker.jar" ]

1. built the m=jar file without changing the properties no errors
2. after changing the configuration to the Postgres container it is unable to connect and the dependencies were added prior

Why this state is happening cannot resolve the root cause for this , can any one sort this out?