How to Start Spring Boot Applications without Database Dependency?

Starting Spring Boot Applications without Database Dependency

To ensure that Spring Boot applications can start successfully even in the absence of a database, certain configurations must be implemented.

Exception Encountered

When attempting to launch the application without an operational database, the following exception occurs:

org.hibernate.HibernateException: Access to DialectResolutionInfo cannot be null when 'hibernate.dialect' not set

Cause

This error originates from Hibernate's reliance on database metadata to determine the appropriate dialect for executing SQL statements. Without a database connection, Hibernate cannot obtain this information.

Solution

To resolve this issue, the following configuration settings must be included in the application.yml file:

spring:
  datasource:
    driverClassName: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/schema
    username: root
    password: root
    continueOnError: true
    initialize: false
    initialSize: 0
    timeBetweenEvictionRunsMillis: 5000
    minEvictableIdleTimeMillis: 5000
    minIdle: 0

  jpa:
    show-sql: true
    hibernate:
      ddl-auto: none
      naming_strategy: org.hibernate.cfg.DefaultNamingStrategy
    properties:
      hibernate:
        dialect: org.hibernate.dialect.MySQL5Dialect
        hbm2ddl:
          auto: none
        temp:
          use_jdbc_metadata_defaults: false

These settings configure the following:

• Datasource information: Specify the database connection details. continueOnError ensures the application continues even if the database is unavailable.
• Initialize: False prevents the application from creating the schema automatically.

• Hibernate properties:

  • Dialect: Manually set the database dialect to overcome the missing metadata.
  • hbm2ddl.auto: Set to "none" to disable automatic schema generation.
  • temp.use_jdbc_metadata_defaults: Disable the use of JDBC metadata to avoid the exception.

The above is the detailed content of How to Start Spring Boot Applications without Database Dependency?. For more information, please follow other related articles on the PHP Chinese website!