I am studying while creating an application that uses Spring Boot and PostgreSQL DB.
The other day I created a Spring app that uses PosgreSQL testdb with the following settings


spring.datasource.driver-class-name = org.postgresql.Driver
spring.datasource.url = jdbc: postgresql: // localhost: 5432/testdb
spring.datasource.username = XXXX
spring.datasource.password = XXXX

Currently, I have packaged this app and am trying to start it in an environment different from the development environment, but the DB specification part is not working after starting, and it seems that the external connection setting of PostgeSQL is not working well.

The goal is to be able to connect to testdb in the development environment in an external environment.

What I tried

Currently[Settings for connecting to PostgreSQL from other terminals]I set PostgreSQL as shown in the above, and in the test using A5M2, the connection was successful.
Therefore, I suspect that the cause is probably in the contents of aplication.properties, but I have not been able to resolve it.

If i have any idea about the missing settings or causes, please do so.

Environment, tools, etc.

OS: windows10 (both development and external)
Development tools: STS
Language: Java Spring
Executable: jar (confirmed to start the application itself)
Test tool: A5M2